US20070233844A1 - Relay device and communication system - Google Patents

Relay device and communication system Download PDF

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Publication number
US20070233844A1
US20070233844A1 US11/723,466 US72346607A US2007233844A1 US 20070233844 A1 US20070233844 A1 US 20070233844A1 US 72346607 A US72346607 A US 72346607A US 2007233844 A1 US2007233844 A1 US 2007233844A1
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United States
Prior art keywords
relay
relay device
communication
connection
communication device
Prior art date
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Abandoned
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US11/723,466
Inventor
Yoshifumi Tanimoto
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Murata Machinery Ltd
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Murata Machinery Ltd
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Filing date
Publication date
Priority claimed from JP2006090692A external-priority patent/JP4333684B2/en
Priority claimed from JP2006090691A external-priority patent/JP4535019B2/en
Priority claimed from JP2006090690A external-priority patent/JP4492575B2/en
Application filed by Murata Machinery Ltd filed Critical Murata Machinery Ltd
Assigned to MURATA KIKAI KABUSHIKI KAISHA reassignment MURATA KIKAI KABUSHIKI KAISHA ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: TANIMOTO, YOSHIFUMI
Publication of US20070233844A1 publication Critical patent/US20070233844A1/en
Priority to US13/341,711 priority Critical patent/US8499083B2/en
Abandoned legal-status Critical Current

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    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L67/00Network arrangements or protocols for supporting network services or applications
    • H04L67/01Protocols
    • H04L67/10Protocols in which an application is distributed across nodes in the network
    • H04L67/1095Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L67/00Network arrangements or protocols for supporting network services or applications
    • H04L67/50Network services
    • H04L67/56Provisioning of proxy services
    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04LTRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L67/00Network arrangements or protocols for supporting network services or applications
    • H04L67/50Network services
    • H04L67/56Provisioning of proxy services
    • H04L67/568Storing data temporarily at an intermediate stage, e.g. caching

Definitions

  • the present invention relates to technology for relaying data transmitted and received between communication devices.
  • VPN Virtual Private Network
  • data transmitted from a terminal located inside a private network can be relayed to a terminal located in another private network via the Internet.
  • LAN Local Area Network
  • LAN of a headquarter office and a LAN of a branch office via the VPN
  • data can be relayed between terminals connected to different LANs via the Internet.
  • TCP Transmission Control Protocol
  • the technology such as the VPN is basically technology for establishing a connection between networks, for example, between a LAN and a LAN, and is not technology for establishing a connection between individual terminals. Therefore, the technology such as the VPN is technology for enabling communication to be carried out between networks in which the VPN is developed as an infrastructure, and is not technology for supporting a case in which an individual personally demands a communication with a specific network.
  • performance of a relay device may decrease due to a fact that resources may become insufficient when a plurality of connections are generated according to the request from terminals.
  • preferred embodiments of the present invention provide a system in which relaying of data between networks connected via the Internet can be set dynamically.
  • Preferred embodiments of the present invention also provide a system in which relaying of data between networks connected via the Internet can be set dynamically according to a request of each terminal.
  • a relay device can carry out communication with a first communication device, and includes a relay unit and a holding unit.
  • the relay unit relays data received from the first communication device to another relay device.
  • the holding unit inquires a status of the other relay device to a server device.
  • the holding unit carries out a connection request to the other relay device, dynamically establishes a relay connection with the other relay device, and holds the established relay connection.
  • the other relay device can carry out communication with a second communication device.
  • the relay device relays the data received from the first communication device to the other relay device to further relay the data to the second communication device.
  • the holding unit also establishes relay connections with a plurality of relay devices, and the relay unit uses the plurality of the relay connections to relay the data to the plurality of the relay devices.
  • the holding unit can separately disconnect the relay connections held with the plurality of the relay devices.
  • a communication system for relaying data between terminals includes a first relay device that can carry out communication with a first communication device, a server device, and a second relay device that can carry out communication with a second communication device.
  • the first relay device includes a holding unit.
  • the holding unit inquires a status of the second relay device to the server device and the second relay device is capable of accepting a connection
  • the holding unit carries out a connection request to the second relay device, dynamically establishes a relay connection with the second relay device, and holds the established relay connection.
  • the first relay device relays data received from the first communication device to the second relay device, and the second relay device further relays the data to the second communication device.
  • the first communication device and the second communication device are respectively provided in different private networks. Accordingly, a connection request for a TCP connection cannot be carried out to the first communication device and the second communication device from an external network.
  • a relay device can carry out communication with a first communication device.
  • the relay device includes an accepting unit and a holding unit.
  • the accepting unit accepts a relay transmission instruction designating another relay device from the first communication device.
  • the holding unit inquires a status of the other relay device to the server device.
  • the holding unit carries out a connection request to the other relay device, dynamically establishes a relay connection with the other relay device, and holds the established relay connection.
  • the other relay device can carry out communication with a second communication device.
  • the relay device relays data received from the first communication device to the other relay device, and the other relay device further relays the data to the second communication device.
  • the holding unit When the other relay device is incapable of accepting a connection, the holding unit notifies such a connection impossible state to the first communication device.
  • the holding unit receives a notification from the server device that the other relay device has become capable of accepting a connection, the holding unit notifies a connection possible state to the first communication device.
  • a communication system for relaying data between terminals includes a first relay device that can carry out communication with a first communication device, a server device, and a second relay device that can carry out communication with a second communication device.
  • the first relay device includes an accepting unit and a holding unit.
  • the accepting unit accepts a relay instruction of data designating the second relay device from the first communication device.
  • the holding unit inquires a status of the second relay device to the server device.
  • the holding unit carries out a connection request to the second relay device, dynamically establishes a relay connection with the second relay device, and holds the established relay connection.
  • the first relay device relays data received from the first communication device to the second relay device so that the second relay device can further relay the data to the second communication device.
  • the first communication device and the second communication device are respectively provided in different private networks.
  • a connection request for a TCP connection cannot be carried out to the first communication device and the second communication device from an external network.
  • a relay device can carry out communication with a first communication device.
  • the relay device includes an accepting unit and a holding unit.
  • the accepting unit accepts a relay transmission instruction designating another relay device from the first communication device.
  • the holding unit inquires a status of the other relay device to the server device.
  • the holding unit dynamically establishes a relay connection with the other relay device, and holds the established relay connection.
  • the holding unit sets such relay connection to be shared with the first communication device.
  • the other relay device can carry out communication with the second communication device.
  • the relay device relays data received from the first communication device to the other relay device, and the other relay device further relays the data to the second communication device.
  • the holding unit disconnects the relay connection held with the other relay device.
  • a communication system for relaying data between terminals includes a first relay device that can carry out communication with a first communication device, a server device, and a second relay device that can carry out communication with the second communication device.
  • the first relay device includes an accepting unit and a holding unit.
  • the accepting unit accepts a relay transmission instruction of data designating the second relay device from the first communication device.
  • the holding unit inquires a status of the second relay device to the server device.
  • the holding unit dynamically establishes a relay connection with the second relay device and holds the established relay connection.
  • the holding unit sets such relay connection to be shared with the first communication device.
  • the first relay device relays data received from the first communication device to the second relay device, and the second relay device further relays the data to the second communication device.
  • the first communication device and the second communication device are respectively provided in different private networks.
  • a connection request for a TCP connection cannot be carried out to the first communication device and the second communication device from an external network.
  • the relay device of the present invention inquires a status of another relay device to the server device.
  • the relay device When the other relay device is capable of accepting a connection, the relay device carries out a connection request, and establishes and holds a relay connection with the other relay device. Therefore, a communication device, which can carry out communication with the relay device, can carry out communication via the private network with a communication device, which can carry out communication with the other relay device.
  • the relay device of the present invention can establish a relay connection with a plurality of relay devices, and hold the established relay connections. Therefore, when communication devices to which communication is to be carried out belong to different networks, a plurality of connections can be generated independently.
  • the relay device of the present invention can independently disconnect each of the relay connections being held with a plurality of the relay devices. Therefore, the relay device of the present invention can maintain only the connections that are necessary for communication, and resources can be utilized efficiently.
  • the relay device of the present invention accepts a relay transmission instruction designating the other relay device from the first communication device, and inquires a status of the other relay device to the server device.
  • the relay device dynamically establishes a relay connection with the other relay device and holds the established relay connection. Therefore, by carrying out a request designating a relay destination to the relay device of the present invention, a communication device, which can carry out communication with the relay device of the present invention, can carry out communication with a communication device, which can carry out communication with the other relay device. Since a connection is established between the relay devices according to a request from the communication device, a network of a communication destination can be selected and a connection can be established more dynamically.
  • the relay device When receiving a notification from the server device that the other relay device has become capable of accepting a connection, the relay device notifies a connection possible state to the first communication device. Accordingly, at a point of time when a preparation is completed at the relay destination, a relay transmission can be started immediately.
  • a terminal which has carried out a connection request to the relay device, can exclusively use the established connection.
  • the relay device of the present invention accepts a relay transmission instruction designating another relay device from the first communication device.
  • the relay device of the present invention sets the first communication device to share the already established relay connection. Therefore, by carrying out a request designating a relay destination to the relay device of the present invention, a communication device, which can carry out communication with the relay device of the present invention, can carry out communication with a communication device, which can carry out communication with the other relay device.
  • the already established relay connection is shared. Therefore, processing load for establishing a connection can be reduced, and resources can be saved.
  • the relay connection established with the other relay device is maintained. Accordingly, an end of communication of one communication device does not influence a communication of another communication device.
  • a communication device sharing the relay connection can use the relay connection until the communication of the communication device itself is completed.
  • FIG. 1 illustrates a configuration of a communication system according to a first preferred embodiment of the present invention.
  • FIG. 2 illustrates a registration example of a relay device database.
  • FIG. 3 is a flowchart illustrating a processing carried out in the communication system according to the first preferred embodiment of the present invention.
  • FIG. 4 is a flowchart illustrating a processing carried out in the communication system focusing on a relay device.
  • FIG. 5 is a flowchart illustrating a processing carried out in the communication system focusing on a relay device.
  • FIG. 6 illustrates an imaginary state in which a plurality of relay connections are established.
  • FIG. 7 illustrates a configuration of a communication system according to a second preferred embodiment of the present invention.
  • FIG. 8 illustrates a registration example of a relay connection database.
  • FIG. 9 is a flowchart illustrating a processing carried out in the communication system according to the second preferred embodiment of the present invention.
  • FIG. 10 is a flowchart illustrating a processing carried out in the communication system focusing on a relay device.
  • FIG. 11 is a flowchart illustrating a processing carried out in the communication system focusing on a relay device.
  • FIG. 12 illustrates a registration example of a relay connection database.
  • FIG. 13 is a flowchart illustrating a processing carried out in a communication system according to a third preferred embodiment of the present invention.
  • FIG. 14 is a flowchart illustrating a processing carried out in the communication system focusing on a relay device.
  • FIG. 15 is a flowchart illustrating a processing carried out in the communication system focusing on a relay device.
  • FIG. 1 illustrates a configuration of a communication system according to a first preferred embodiment.
  • two Local Area Networks (LANs) 10 and 20 are connected via a Wide Area Network (WAN) 30 .
  • LANs 10 and 20 are an in-house LAN of a company
  • the WAN 30 is a public network such as the Internet. That is, two different private LANs 10 and 20 are connected via a public network such as the Internet.
  • two communication devices 11 and 12 and a relay device 15 are connected in the LAN 10 .
  • the LAN 10 is connected to the WAN 30 via a gateway (GW) 16 .
  • Two communication devices 21 and 22 and a relay device 25 are connected in the LAN 20 .
  • the LAN 20 is connected to the WAN 30 via a gateway 26 .
  • the communication devices 11 and 12 are terminals such as personal computers, and include a network function. Specifically, each of the communication devices 11 and 12 includes a Transmission Control Protocol/Internet Protocol (TCP/IP), and uses the TCP/IP to carry out communication with the relay device 15 and other computers or the like connected to the LAN 10 . In the same manner, each of the communication devices 21 and 22 includes a TCP/IP, and uses the TCP/IP to carry out communication with the relay device 25 and other computers or the like connected to the LAN 20 . The relay devices 15 and 25 and the gateways 16 and 26 can also carry out communication by the TCP/IP.
  • TCP/IP Transmission Control Protocol/Internet Protocol
  • each of the communication devices 21 and 22 includes a TCP/IP, and uses the TCP/IP to carry out communication with the relay device 25 and other computers or the like connected to the LAN 20 .
  • the relay devices 15 and 25 and the gateways 16 and 26 can also carry out communication by the TCP/IP.
  • a server device 35 is connected to the WAN 30 .
  • the WAN 30 is a public network such as the Internet. Therefore, a terminal connected to the LAN 10 , the LAN 20 , or the WAN 30 can establish a TCP connection by designating a global IP address of the server device 35 .
  • a private IP address is assigned to the communication devices 11 and 12 and the relay device 15 connected to the LAN 10 and the communication devices 21 and 22 and the relay device 25 connected to the LAN 20 .
  • the gateways 16 and 26 function as a firewall, and a connection cannot be established directly from an external network by designating a terminal located inside of the network. Therefore, a terminal or the like connected to the WAN 30 has restrictions when carrying out a TCP connection request to the relay device 15 or 25 .
  • the gateways 16 and 26 are set such that communication designating a specific port corresponding to the relay servers 15 and 25 can be carried out to the gateways 16 and 26 , respectively.
  • SIP Session Initiation Protocol
  • FIG. 2 illustrates a registration example of a relay device database 351 managed by the server device 35 .
  • the relay devices A, B, and C are device names that are assigned to the relay device 15 or the relay device 25 , for example.
  • Flags of a Uniform Resource Locator (URL), an IP address, and a login status are set for each of the relay devices A, B, and C.
  • URL Uniform Resource Locator
  • An IP address of each of the relay devices registered in the relay device database 351 is not an IP address in a private network, but is a global IP address converted by a gateway by a function such as a Network Address Translation (NAT) or an IP masquerade.
  • the relay device 15 is assigned with a private address in the LAN 10 .
  • the IP address assigned to the relay device 15 is converted into a global IP address by the gateway 16 .
  • Each of the relay devices A through C establishes a connection with the server device 35 , and logs into the server device 35 .
  • a “status” field of the relay device database 351 stores information indicating whether each of the relay devices A through C is currently under a logged-in status or a logged-out status with respect to the server device 35 .
  • the server device 35 determines that a TCP connection is prepared to be established between the logged-in relay devices.
  • a status in which the relay device is logged in the server device 35 indicates a status in which the relay device is capable of accepting a TCP connection request transmitted from another terminal.
  • FIG. 3 illustrates a flow of the processing of the entire communication system including the relay devices 15 and 25 and the server device 35 .
  • a Session Initiation Protocol (SIP) is used for communication between the relay device 15 and the server device 35 , and between the relay device 25 and the server device 35 .
  • SIP Session Initiation Protocol
  • other protocols may also be used.
  • Each of the relay devices 15 and 25 transmits a “REGISTER request message” of the SIP to the server device 35 at initialization or periodically to notify position information (for example, an IP address, and/or a port number) of the relay device to the server device 35 .
  • the server device 35 manages the relay device database 351 illustrated in FIG. 2 according to the notified position information.
  • the server device 35 can carry out communication with each of the relay devices over the gateway according to the position information.
  • the relay device 15 and the relay device 25 are logged in the server device 35 .
  • the relay device 25 notifies logout status information to the server device 35 (step S 101 ), and the server device 35 responds to the notification (step S 102 ).
  • the server device 35 executes a logout processing of the relay device 25 , and updates the “status” field of the relay device 25 in the relay device database 351 to “logout”.
  • step S 103 when the relay device 15 carries out a notification request of the status information to the server device 35 (step S 103 ), the server device 35 carries out a response (step S 104 ), and notifies that the relay device 25 is logged-out (step S 105 ). The relay device 15 responds to this notification (step S 106 ).
  • the relay device 25 notifies login status information to the server device 35 (step S 107 ), and the server device 35 responds to the notification (step S 108 ).
  • the server device 35 executes the login processing of the relay device 25 , and updates the “status” field of the relay device database 351 to “login”. Furthermore, the server device 35 notifies the relay device 15 that the relay device 25 has logged in (step S 109 ). The relay device 15 responds to this notification (step S 110 ).
  • this connection request is an “INVITE request message” of the SIP, and includes TCP connection information in a body portion following a blank line.
  • the connection request includes an IP address (200.1.1.1) and a TCP port number (6109) or the like of the relay device 15 (transmitter).
  • the server device 35 relays the connection request to the relay device 25 (step S 112 ).
  • the relay device 25 which has received the connection request, transmits a response to the server device 35 to permit a connection (step S 113 ). As illustrated in FIG.
  • this response is “200 OK response message” of the SIP, and includes TCP connection information in a body portion following a blank line.
  • the response includes an IP address (200.2.2.2) and a TCP port number (7109) or the like of the relay device 25 (transmitter).
  • the server device 35 relays the response to the relay device 15 (step S 114 ).
  • the relay device 15 and the relay device 25 use the INVITE request and the OK response of the SIP to exchange TCP connection information, and carry out a negotiation for establishing a TCP connection.
  • the relay device 15 transmits a TCP connection request to the relay device 25 (step S 115 ). Accordingly, a TCP connection is established between the relay device 15 and the relay device 25 .
  • the above-described processing is executed by a network administrator of the LAN 10 or the LAN 20 , for example. That is, in order to prepare such that a connection with another LAN can be carried out dynamically, a relay device in a network is logged into the server device 35 by the network administrator as illustrated at step S 107 . Accordingly, a preparation is completed for receiving a TCP connection request from another relay device.
  • the network administrator wishes to carry out a connection with another LAN, the network administrator accesses the server device 35 , and acquires status of a destination relay device. When the network administrator learns that the destination relay device is under a logged-in status, the network administrator transmits a connection request to the server device 35 .
  • the relay device 15 transmits an INVITE request of the SIP via the server device 35 to establish a TCP connection (media session) for relaying.
  • a relay channel as a media session is generated by a call control protocol, a relay communication channel can be established dynamically.
  • the relay device 15 and the relay device 25 hold the established TCP connection.
  • the relay device 15 receives data from the communication device 11 , 12 or the like to be transmitted to the communication device 21 , 22 or the like, the relay device 15 relays the received data to the relay device 25 (step S 116 ).
  • the relay device 25 further relays the relayed data to the communication device 21 , 22 or the like. Data transmitted from the communication device 21 , 22 or the like is also relayed to the communication device 11 , 12 , or the like via the relay device 25 and the relay device 15 (step S 117 ).
  • each of the relay devices 15 and 25 manages a list of device names of communication devices connected to each of the LANs 10 and 20 , respectively.
  • the relay device 15 and the relay device 25 exchange the list.
  • a device name of a relay device of a LAN of a transmission destination and a device name of a communication device of the transmission destination are designated.
  • a unique device name (registered in the relay device database 351 ) is assigned to a relay device using such a communication system, by designating both the device name of the relay device and the device name of the communication device, the communication device of the transmission destination can be identified uniquely. For example, a name such as “communication device name@relay device name” may be used.
  • Each relay device knows an association between a communication device name and an IP address for a communication device connected to the LAN to which the relay device itself is also connected. Therefore, the relay device can relay data to a communication device designated by “communication device name@relay device name”.
  • the relay device 15 transmits a disconnection request for the relay device 25 to the server device 35 (step S 118 ).
  • the server device 35 relays the disconnection request to the relay device 25 (step S 119 ).
  • a response from the relay device 25 is transmitted to the server device 35 (step S 120 ), and relayed to the relay device 15 (step S 121 ).
  • FIG. 4 is a flowchart focusing on a processing carried out by the relay device 15 in the processing described with reference to FIG. 3 .
  • the relay device 15 transmits a starting request for starting a relay connection to the server device 35 (step S 201 ).
  • the relay-device 25 is designated as the relay destination in the starting request.
  • the relay device 15 stands by until receiving a login notification (step S 203 ).
  • the process proceeds onto step S 204 .
  • the relay device 15 When a determination is made at step S 202 that the relay device 25 of the relay destination is logged in, the relay device 15 generates TCP connection information (step S 204 ), and transmits a connection request (step S 205 ). Then, the relay device 15 stands by for a response from the relay device 25 (step S 206 ). When receiving a response (step S 206 : YES), the relay device 15 analyzes the TCP connection information included in the received response (step S 207 ). That is, the relay device 15 acquires port number information or the like included in the response transmitted from the relay device 25 . Then, the relay device 15 carries out a TCP connection with the relay device 25 (step S 208 ).
  • step S 209 Under a state in which a TCP connection is established and held, when the communication device 11 or the like transmits relay data (step S 209 : YES), the relay device 15 relays the data to the communication device 21 or the like (step S 210 ).
  • step S 211 When the relay device 15 receives relay data to be relayed to the communication device 11 or the like (step S 211 : YES), the relay device 15 relays the data to the communication device 11 or the like of the relay destination (step S 212 ).
  • step S 213 YES
  • the relay device 15 transmits a response (step S 214 ) and disconnects the TCP connection (step S 215 ).
  • the relay device 15 transmits a disconnection request to the relay device 25 (step S 217 ).
  • the relay device 15 receives a response (step S 218 : YES)
  • the relay device 15 disconnects the TCP connection (step S 219 ).
  • FIG. 5 is a flowchart focusing on a processing carried out by the relay device 25 in the processing described with reference to FIG. 3 .
  • a network administrator of the LAN 20 determines whether or not to prepare for establishing a connection with another LAN.
  • an operation is performed for validating a relay function of the relay device 25 .
  • the relay device 25 transmits a login command to the server device 35 (step S 302 ).
  • the relay device 25 receives a response from the server device 35 (step S 303 ), and a processing for validating the relay function is completed.
  • the relay device 15 dynamically establishes a TCP connection with the relay device 25 .
  • data can be transmitted and received via the WAN 30 such as the Internet.
  • the WAN 30 such as the Internet.
  • LANs may be connected fixedly by using the conventionally used VPN.
  • the communication system of the present preferred embodiment can be used.
  • the relay device when a connection environment (an IP address and/or a port number) of the relay device of the other party is changed, the relay device carries out a negotiation first (steps S 111 through S 114 ). Therefore, a connection for relaying data can be established reliably.
  • the relay devices 15 and 25 of the present preferred embodiment can establish a TCP connection with a plurality of relay devices.
  • the relay device 15 can establish a separate TCP connection with each of three relay devices 25 , 45 and 55 .
  • a method for establishing a TCP connection with the relay devices 45 and 55 is the same as the processing carried out with respect to the relay device 25 .
  • Each of the relay devices 15 and 25 or the like establishes a TCP connection with a plurality of relay devices, and relays data to the plurality of the relay devices.
  • the relay device 15 relays data transmitted from a certain communication device to the relay device 45 , and relays data transmitted from another communication device to the relay device 55 .
  • a method for disconnecting the TCP connection established with each of the relay devices 45 and 55 is also the same as the processing carried out with respect to the relay device 25 . That is, a TCP connection can be established independently with each of the plurality of the relay devices 25 , 45 , and 55 , and the TCP connection can be disconnected independently.
  • the communication system of the present preferred embodiment when a plurality of LANs are connected, the plurality of the LANs are connected as one VPN. Meanwhile, according to the communication system of the present preferred embodiment, a connection is established independently with just a relay device to which a communication is to be carried out, and a connection established with a relay device to which a communication is no longer necessary to be carried out can be disconnected independently. Therefore, efficient communication system can be constituted without consuming unnecessary resources.
  • a connection is established dynamically between relay devices according to an instruction from a network administrator.
  • a connection is established between relay devices according to a designation from a communication device.
  • a network administrator by predicting a status of communication to be generated between the communication devices, a network administrator carries out an operation for establishing or disconnecting a connection between the relay devices.
  • a control is carried out to establish or disconnect a connection between the relay devices more dynamically according to a communication processing that generates from a communication device.
  • FIG. 7 illustrates an example of a configuration of a communication system according to the second preferred embodiment of the present invention.
  • a LAN 40 is added to the system configuration illustrated in FIG. 1 .
  • the basic system configuration illustrated in FIG. 7 is the same as the first preferred embodiment.
  • a communication device 41 and a relay device 45 are connected to the LAN 40 , and the LAN 40 is connected to a WAN 30 via a gateway 46 .
  • the relay devices 15 , 25 , and 45 include relay connection databases 151 , 251 , and 451 , respectively.
  • FIG. 8 illustrates an example of registration of the relay connection database 151 stored in the relay device 15 .
  • the relay connection database 151 is a database for managing a TCP connection currently established by the relay device 15 .
  • a “client” field stores a setting of a device name of a communication device that has requested a connection to be established with a relay device (hereinafter referred to as a “requesting communication device”).
  • a relay device hereinafter referred to as a “requesting communication device”.
  • “ClientX” and “ClientY” in FIG. 8 are a device name assigned to the communication device 11 , 21 or the like.
  • “Relay destination URL” and “IP address” fields store a setting of a URL and an IP address of a relay device of a relay destination, respectively.
  • Connection number” field stores a setting of a port number of a generated TCP connection.
  • “Generated time” field stores a setting of time when a TCP connection has been established.
  • a TCP connection is established with a relay device of a communication destination.
  • a device that can use such a TCP connection for carrying out communication is only the requesting communication device. That is, as illustrated in FIG. 8 , one-to-one relation is established for a communication device and a TCP connection.
  • the contents of the relay connection databases 251 and 451 are the same as the relay connection databases 151 illustrated in FIG. 8 .
  • the relay connection databases 251 and 451 include registration of a status of a TCP connection currently established by the relay devices 25 and 45 , respectively.
  • FIG. 9 illustrates a flow of the processing of the entire communication system including the communication devices 11 and 12 , the relay devices 15 and 25 , and the server device 35 . Further, in the following description, a description will be made of an example in which the SIP is used for the communication between the relay devices 15 and the server device 35 and between the server device 35 and the relay device 25 . However, other protocols may also be used.
  • each of the relay devices 15 and 25 transmits a “REGISTER request message” of the SIP to the server device 35 at initialization or periodically to notify position information (for example, an IP address and/or a port number) of the relay device to the server device 35 .
  • position information for example, an IP address and/or a port number
  • FIG. 9 under an initial state, the relay device 15 and the relay device 25 are logged in the server device 35 .
  • the relay device 25 notifies logout status information to the server device 35 (step S 401 ), and the server device 35 responds to the notified logout status information (step S 402 ).
  • the server device 35 executes a logout processing of the relay device 25 , and updates the “status” field of the relay device 25 in the relay device database 351 to “logout”.
  • the communication device 11 transmits a relay transmission request of data and a status confirmation request, which designate the relay device 25 , to the relay device 15 (step S 403 ).
  • the relay device 15 carries out a notification request of the status information to the server device 35 (step S 404 )
  • the server device 35 carries out a response (step S 405 ) and notifies the relay device 15 that the relay device 25 is logged out (step S 406 ).
  • the relay device 15 responds to the notification (step S 407 ).
  • the relay device 15 notifies the communication device 11 that the relay device 25 is a logged out (step S 408 ). Accordingly, the communication device 11 stands by until the relay device 25 logs in.
  • the relay device 25 notifies login status information to the server device 35 (step S 409 ), and the server device 35 responds to the notified login status information (step S 410 ).
  • the server device 35 executes a login processing of the relay device 25 , and updates the “status” field of the relay device database 351 to “login”.
  • the server device 35 also notifies the relay device 15 that the relay device 25 has logged in (step S 411 ).
  • the relay device 15 responds to the notification (step S 412 ).
  • the relay device 15 notifies the communication device 11 that the relay device 25 has logged in (step S 413 ).
  • the communication device 11 When the communication device 11 , which has been on standby, receives the notification carried out at step S 413 , the communication device 11 carries out a relay transmission request again designating the relay device 25 (step S 414 ). Further, in the second preferred embodiment, the communication device 11 is provided to standby until receiving a notification that the relay device 25 has logged in. However, as another preferred embodiment, without standing by for such a notification, the communication device 11 may periodically transmit a relay transmission request to the relay device 15 .
  • the relay device 15 When the relay device 15 receives the relay transmission request from the communication device 11 , the relay device 15 transmits a connection request for the relay device 25 to the server device 35 (step S 415 ).
  • the connection request is an “INVITE request message” of the SIP, and includes TCP connection information.
  • the server device 35 relays the connection request to the relay device 25 (step S 416 ).
  • the relay device 25 transmits a response to the server device 25 to permit a connection (step S 417 ).
  • the response is “200 OK response message” of the SIP, and includes TCP connection information.
  • the server device 35 relays the response to the relay device 15 (step S 418 ).
  • the relay device 15 and the relay device 25 exchange the TCP connection information as described above.
  • the relay device 15 transmits a TCP connection request to the relay device 25 (step S 419 ). Accordingly, a TCP connection is established between the relay device 15 and the relay device 25 .
  • the above-described processing is carried out dynamically, for example, when a communication processing from the communication device 11 to the communication device 21 generates. That is, the relay devices are not connected fixedly, but a connection is carried out when traffic generates. However, in order to prepare for a connection request from a relay device of another end, a network administrator is required to be prepared by logging a relay device within a network into the server device 35 as illustrated at step S 409 .
  • the relay device 15 receives an instruction from the communication device 11 , and the relay device 15 transmits an INVITE request of the SIP via the server device 35 to establish a relay TCP connection (media session). That is, at a point of time when a connection request from a communication device generates, since a relay channel as a media session is generated by a call control protocol, a relay communication channel can be established dynamically.
  • the relay device 15 and the relay device 25 hold the established TCP connection.
  • the communication device 11 transmits data addressed to the communication device 21 , 22 or the like (step S 421 )
  • the relay device 15 relays the data to the relay device 25 (step S 422 ).
  • the relay device 25 further relays the relayed data to the communication device 21 , 22 or the like.
  • the data transmitted from the communication device 21 , 22 or the like is relayed to the relay device 15 via the relay device 25 in the same manner (step S 423 ) and relayed further to the communication device 11 via the relay device 15 (step S 424 ).
  • the communication device 11 transmits a disconnection instruction to the relay device 15 (step S 425 ).
  • the relay device 15 transmits a disconnection request for the relay device 25 to the server device 35 (step S 426 ).
  • the server device 35 relays the received disconnection request to the relay device 25 (step S 427 ).
  • a response from the relay device 25 is transmitted to the server device 35 (step S 428 ) and relayed to the relay device 15 (step S 429 ). Accordingly, the TCP connection between the relay device 15 and the relay device 25 is disconnected, and the relay device 15 notifies the communication device 11 that the TCP connection has been disconnected (step S 430 ).
  • step S 431 when another communication device 12 carries out a relay transmission request designating the relay device 25 again (step S 431 ), a connection request is transmitted from the relay device 15 to the server device 35 (step S 432 ).
  • step S 432 when the relay device 25 is under a logged-out status, the server device 35 notifies the logged-out status (step S 433 ), and the communication device 12 is notified that the relay device 25 is under a logged-out status.
  • the communication device 12 when the relay device 25 logs in, the communication device 12 carries out a relay transmission request to the relay device 25 again. Accordingly, a TCP connection is established between the relay device 15 and the relay device 25 .
  • FIG. 10 is a flowchart focusing on a processing carried out by the relay device 15 in the processing described with reference to FIG. 9 .
  • the relay device 15 confirms whether or not a relay instruction from the communication device 11 , 12 or the like is generated (step S 501 ).
  • the relay device 15 confirms whether or not a status monitoring instruction is generated (step S 502 ).
  • the relay device 15 checks whether or not the relay device of the relay destination is logged in (step S 503 ).
  • the relay device 15 confirms that the relay device of the relay destination is logged out (step S 503 : NO)
  • the relay device 15 stands by until receiving a login notification (step S 504 ).
  • stepS 504 When receiving a notification from the server device 35 indicating that the relay device of the relay destination has logged in (stepS 504 : YES), the relay device 15 notifies the requesting communication device that the relay destination has logged in (step S 505 ). Then, the relay device 15 stands by until receiving a relay instruction from the communication device 11 , 12 or the like again (step S 506 ). When the relay device 15 receives a relay instruction, the process proceeds onto step S 508 . When a determination is made at step S 503 that the relay device of the relay destination is logged in, the process proceeds immediately onto step S 508 .
  • step S 502 When a status monitoring instruction is not included in the request from the communication device (step S 502 : NO), if the relay destination is logged in (step S 507 : YES), the process proceeds onto step S 508 . If the relay destination is not logged in, the process returns to step S 502 and the processing is repeated. That is, when a status monitoring instruction has been received from a requesting communication device, the relay device 15 monitors the relay device of the relay destination until the relay device of the relay destination logs in. When receiving a notification that the relay device of the relay destination has logged in, the relay device 15 notifies such information also to the requesting communication device.
  • the relay device 15 generates TCP connection information (step S 508 ) and transmits a connection request (step S 509 ).
  • the relay device 15 stands by until receiving a response from the relay device 25 (step S 510 ).
  • the relay device 15 carries out an error notification to the requesting communication device (step S 511 ).
  • the process returns to step S 501 and the processing is repeated.
  • the relay device 15 analyzes the TCP connection information included in the received response (step S 512 ). That is, the relay device 15 acquires port number information or the like included in the response transmitted from the relay device 25 .
  • the relay device 15 carries out a TCP connection to the relay device 25 (step S 513 ).
  • the relay device 15 notifies the requesting communication device that a connection has been established with the relay destination (step S 514 ).
  • the relay device 15 registers information of the newly established TCP connection in the relay connection database 151 (step S 515 ).
  • step S 516 when relay data is transmitted from the communication device 11 or the like (step S 516 : YES), the relay device 15 relays the data to the communication device 21 or the like (step S 517 ).
  • step S 518 When receiving relay data to be relayed to the communication device 11 or the like (step S 518 : YES), the relay device 15 relays the data to the communication device 11 or the like of the relay destination (step S 519 ).
  • step S 520 When receiving a disconnection request from the relay device 25 (step S 520 : YES), the relay device 15 transmits a response (step S 521 ) and disconnects the TCP connection (step S 522 ).
  • the relay device 15 transmits a disconnection request to the relay device 25 of the relay destination (step S 524 ).
  • the relay device 15 disconnects the TCP connection (step S 526 ). Then, the relay device 15 notifies the requesting communication device that a connection with the relay destination has been disconnected (step S 527 ), and the information of the TCP connection registered in the relay connection database 151 is deleted (step S 528 ).
  • a TCP connection is established dynamically with the relay device of the relay destination, and communication can be carried out between private networks.
  • a connection necessary for such communication is established. Therefore, resources can be utilized efficiently.
  • a communication connection is established according to a request from a certain communication device
  • only such a requesting communication device is permitted to use the established communication connection.
  • a TCP connection is established between the relay device 15 and the relay device 25 according to the request.
  • the established TCP connection is used only for the communication between the communication device 11 and the communication device 21 .
  • the relay device 15 and the relay device 25 use the TCP connection just for relaying the data transmitted and received between the communication device 11 and the communication device 21 . Therefore, a connection established according to a request from a certain communication device is used exclusively by such a communication device.
  • a connection is carried out between relay devices according to a request from a communication device.
  • another communication device shares the already established connection. This feature differs from the second preferred embodiment.
  • a description will be made primarily of aspects that are different from the second preferred embodiment.
  • FIG. 12 illustrates an example of registration of the relay connection database 151 stored in the relay device 15 .
  • a plurality of clients (communication devices) are associated with one TCP connection.
  • a relay transmission request has generated from two communication devices (ClientX and ClientY), and both of the communication devices designate the same relay device (Relayserver1@sample.net). Therefore, the two communication devices are sharing a TCP connection with a connection number 49583.
  • the contents of the relay connection databases 251 and 451 stored in the relay devices 25 and 45 , respectively, are the same as the relay connection database 151 illustrated in FIG. 12 .
  • the relay connection databases 251 and 451 store a status of a TCP connection currently established by the relay devices 25 and 45 , respectively.
  • FIG. 13 illustrates a flow of a processing of the entire communication system including the communication devices 11 and 12 , the relay devices 15 and 25 , and the server device 35 . Further, in the following description, a description will be made of an example in which the SIP is used for the communication between the relay device 15 and the server device 35 , and between the server device 35 and the relay device 25 . However, other protocols may also be used.
  • step S 701 to step S 724 in FIG. 13 corresponds to the processing from step S 401 to step S 424 in FIG. 9 . Since the processing is the same, a description will be omitted. That is, the communication device 11 generates a relay transmission request designating the relay device 25 , and a TCP connection is established between the relay device 15 and the relay device 25 . Then, data is transmitted and received between the communication device 11 and the communication device 21 or the like.
  • a different communication device 12 carries out a relay transmission request designating the relay device 25 again (step S 725 ). Since the TCP connection is currently being established between the relay device 15 and the relay device 25 , the relay device 15 notifies the communication device 12 that a relay transmission of the data can be carried out (step S 726 ). Accordingly, when data is transmitted from the communication device 12 (step S 727 ), the relay device 15 uses the already established TCP connection to relay the data transmitted from the communication device 12 to the relay device 25 (step S 728 ). The relay device 25 also uses the already established TCP connection for relaying the data, which has been transmitted from the communication device 21 or the like to the communication device 12 , to the relay device 15 (step S 729 ). The relay device 15 further transmits the received data to the communication device 12 (step S 730 ).
  • a TCP connection is already established between the relay devices, and when the already established TCP connection can be used for a newly generated relay transmission request, a new TCP connection is not established.
  • a plurality of communication terminals share the same TCP connection. Accordingly, load required for establishing a TCP connection can be reduced, and communication between different networks can be carried out under higher speed.
  • resources of the relay device can be saved. For example, when carrying out communication via the Internet between a plurality of communication terminals connected to the LAN 10 and a plurality of communication terminals connected to the LAN 20 , an increase in the processing speed and saving of the resources are possible and efficient.
  • the above-described third preferred embodiment is also efficient when data volume to be relayed from one communication device is small.
  • the communication device 11 transmits a disconnection instruction to the relay device 15 (step S 731 ). Since the communication device 12 is using the same TCP connection, the relay device 15 does not carry out a processing in particular with respect to the disconnection instruction of step S 731 , and just carries out a response (step S 732 ).
  • the communication device 12 transmits a disconnection instruction to the relay device 15 (step S 733 ). Since the relay device 15 has already received the disconnection instruction from the communication device 11 , the relay device 15 can determine that the shared TCP connection has become unnecessary. Therefore, the relay device 15 transmits a disconnection request for the relay device 25 to the server device 35 (step S 734 ). The server device 35 relays the disconnection request to the relay device 25 (step S 735 ). The relay device 25 transmits a response to the server device 35 (step S 736 ). Then, the server device 35 relays the response to the relay device 15 (step S 737 ). Accordingly, the TCP connection between the relay device 15 and the relay device 25 is disconnected, and the relay device 15 notifies the communication device 11 that the TCP connection has been disconnected (step S 738 ).
  • FIG. 14 is a flowchart focusing on a processing carried out by the relay device 15 in the processing described with reference to FIG. 13 .
  • the relay device 15 confirms whether or not a relay instruction from the communication device 11 or 12 or the like has generated (step S 801 ).
  • the relay device 15 confirms whether or not a TCP connection is already established with a relay device of a relay destination (step S 802 ). That is, the relay device 15 confirms whether or not the same relay device has already been designated by another communication device and a communication is being carried out with such a relay device.
  • the relay device 15 When a connection is already established with the already instructed relay destination (step S 802 : YES), the relay device 15 notifies that data can be relayed to a requesting communication device (step S 815 ). Then, the relay device 15 updates the information of the relay connection database 151 (step S 816 ). That is, since information regarding the TCP connection is already registered in the relay connection database 151 , the relay device 15 just adds a client (communication device). In the example illustrated in FIG. 12 , for example, when ClientX and a TCP connection with a connection number 49583 are associated and stored, the relay device 15 carries out a processing for adding ClientY to the “client” field of such record.
  • the relay device 15 executes the processing from step S 803 to step S 814 .
  • This processing corresponds to the processing from step S 502 to step S 513 in FIG. 10 . Since the processing is the same, a description will be omitted.
  • step S 817 When a state in which a TCP connection is established and held, when relay data is transmitted from the communication device 11 or the like (step S 817 : YES), the data is relayed to the communication device 21 or the like (step S 818 ).
  • step S 819 When receiving relay data to be relayed to the communication device 11 or the like (step S 819 : YES), the relay device 15 relays the data to the communication device 11 or the like of the relay destination (step S 820 ).
  • step S 821 When receiving a disconnection request from the relay device 25 of the relay destination (step S 821 : YES), the relay device 15 transmits a response (step S 822 ) and disconnects the TCP connection (step S 823 ).
  • the relay device 15 notifies the communication device to which relay transmission is being carried out that the connection with the relay destination has been disconnected to (step S 824 ).
  • the disconnection is notified to all of the communication devices (steps S 824 and S 825 ).
  • the relay device 15 checks whether or not the TCP connection instructed to be disconnected is being shared with another communication device (step S 827 ). When such a TCP connection is being shared with another communication device (step S 827 : YES), without disconnecting the TCP connection, a formal disconnection notification is carried out to the communication device that has carried out the disconnection instruction (step S 828 ). Then, the relay device 15 updates the information stored in the relay connection database 151 (stepS 829 ). That is, the relay device 15 deletes information of the client (communication device) that has requested the disconnection instruction from the information of the shared TCP connection. The relay device 15 manages a currently established TCP connection and communication devices sharing the TCP connection at all times as described above.
  • the relay device 15 transmits a disconnection request to the relay device 25 (step S 830 ).
  • the TCP connection is disconnected (step S 832 ).
  • the relay device 15 notifies the requesting communication device that the connection with the relay destination has been disconnected (step S 833 ) and deletes the information of the TCP connection registered in the relay connection database 151 (step S 834 ).
  • a TCP connection is dynamically established with a relay device of a relay destination, and communication can be carried out between private networks. Furthermore, when a relay instruction generates, if a TCP connection is already established with the relay destination, the already established TCP connection is shared. Accordingly, speed of the processing is increased, and resources can be utilized efficiently.

Abstract

A relay device requests a status notification of another relay device to a server device. When the relay device is notified that the other relay device is under a logged-out status, the relay device stands by. When the relay device is notified that the other relay device has logged in, the relay device transmits a connection request to the server device. The server device relays the connection request to the other relay device. A response is transmitted from the other relay device to the server device, and further relayed to the relay device. Accordingly, a TCP connection is established between the relay device and the other relay device. A communication device connected to a different network can transmit and receive data to and from the relay device via the other relay device.

Description

    BACKGROUND OF THE INVENTION
  • 1. Field of the Invention
  • The present invention relates to technology for relaying data transmitted and received between communication devices.
  • 2. Description of the Related Art
  • By using technology such as a Virtual Private Network (VPN) and tunneling, data transmitted from a terminal located inside a private network can be relayed to a terminal located in another private network via the Internet. For example, by establishing a connection between a Local Area Network (LAN) of a headquarter office and a LAN of a branch office via the VPN, data can be relayed between terminals connected to different LANs via the Internet.
  • According to known technology, data is relayed between local systems connected via the Internet. According to this technology, each terminal located within a local system accesses a relay server on the Internet to establish a Transmission Control Protocol (TCP) connection, and uses the established TCP connection to transmit and receive data between the local systems.
  • By using the technology of the VPN and the tunneling, data can be transmitted and received between different LANs connected via the Internet. However, such technology provides a system which is constructed by a fixed setting. That is, a relay device provided on the Internet between the LANs carries out a fixed connection setting between the LANs. Therefore, there is no problem when a VPN connection is preferably established constantly between a headquarter office and a branch office of a company, for example. However, the above-described technology cannot support a case in which a connection is to be established dynamically between different private networks.
  • The technology such as the VPN is basically technology for establishing a connection between networks, for example, between a LAN and a LAN, and is not technology for establishing a connection between individual terminals. Therefore, the technology such as the VPN is technology for enabling communication to be carried out between networks in which the VPN is developed as an infrastructure, and is not technology for supporting a case in which an individual personally demands a communication with a specific network.
  • Meanwhile, when constructing a system in which a connection is established between networks in response to a request from individual terminals, performance of a relay device may decrease due to a fact that resources may become insufficient when a plurality of connections are generated according to the request from terminals.
  • SUMMARY OF THE INVENTION
  • In order to overcome the problems described above, preferred embodiments of the present invention provide a system in which relaying of data between networks connected via the Internet can be set dynamically.
  • Preferred embodiments of the present invention also provide a system in which relaying of data between networks connected via the Internet can be set dynamically according to a request of each terminal.
  • According to an aspect of the present invention, a relay device can carry out communication with a first communication device, and includes a relay unit and a holding unit. The relay unit relays data received from the first communication device to another relay device. The holding unit inquires a status of the other relay device to a server device. When the other relay device is capable of accepting a connection, the holding unit carries out a connection request to the other relay device, dynamically establishes a relay connection with the other relay device, and holds the established relay connection. The other relay device can carry out communication with a second communication device. The relay device relays the data received from the first communication device to the other relay device to further relay the data to the second communication device.
  • The holding unit also establishes relay connections with a plurality of relay devices, and the relay unit uses the plurality of the relay connections to relay the data to the plurality of the relay devices.
  • The holding unit can separately disconnect the relay connections held with the plurality of the relay devices.
  • According to another aspect of the present invention, a communication system for relaying data between terminals includes a first relay device that can carry out communication with a first communication device, a server device, and a second relay device that can carry out communication with a second communication device. The first relay device includes a holding unit. When the holding unit inquires a status of the second relay device to the server device and the second relay device is capable of accepting a connection, the holding unit carries out a connection request to the second relay device, dynamically establishes a relay connection with the second relay device, and holds the established relay connection. The first relay device relays data received from the first communication device to the second relay device, and the second relay device further relays the data to the second communication device.
  • The first communication device and the second communication device are respectively provided in different private networks. Accordingly, a connection request for a TCP connection cannot be carried out to the first communication device and the second communication device from an external network.
  • According to another aspect of the present invention, a relay device can carry out communication with a first communication device. The relay device includes an accepting unit and a holding unit. The accepting unit accepts a relay transmission instruction designating another relay device from the first communication device. The holding unit inquires a status of the other relay device to the server device. When the other relay device is capable of accepting a connection, the holding unit carries out a connection request to the other relay device, dynamically establishes a relay connection with the other relay device, and holds the established relay connection. The other relay device can carry out communication with a second communication device. The relay device relays data received from the first communication device to the other relay device, and the other relay device further relays the data to the second communication device.
  • When the other relay device is incapable of accepting a connection, the holding unit notifies such a connection impossible state to the first communication device. When the holding unit receives a notification from the server device that the other relay device has become capable of accepting a connection, the holding unit notifies a connection possible state to the first communication device.
  • Only data, which has the first communication device as a transmitter or a transmission destination, is relayed over the relay connection held by the holding unit.
  • According to another aspect of the present invention, a communication system for relaying data between terminals includes a first relay device that can carry out communication with a first communication device, a server device, and a second relay device that can carry out communication with a second communication device. The first relay device includes an accepting unit and a holding unit. The accepting unit accepts a relay instruction of data designating the second relay device from the first communication device. The holding unit inquires a status of the second relay device to the server device. When the second relay device is capable of accepting a connection, the holding unit carries out a connection request to the second relay device, dynamically establishes a relay connection with the second relay device, and holds the established relay connection. The first relay device relays data received from the first communication device to the second relay device so that the second relay device can further relay the data to the second communication device.
  • The first communication device and the second communication device are respectively provided in different private networks. A connection request for a TCP connection cannot be carried out to the first communication device and the second communication device from an external network.
  • According to another aspect of the present invention a relay device can carry out communication with a first communication device. The relay device includes an accepting unit and a holding unit. The accepting unit accepts a relay transmission instruction designating another relay device from the first communication device. When a relay connection has not been established yet with the other relay device, the holding unit inquires a status of the other relay device to the server device. When the other relay device is capable of accepting a connection, the holding unit dynamically establishes a relay connection with the other relay device, and holds the established relay connection. When a relay connection is already established with the other relay device, the holding unit sets such relay connection to be shared with the first communication device. The other relay device can carry out communication with the second communication device. The relay device relays data received from the first communication device to the other relay device, and the other relay device further relays the data to the second communication device.
  • When receiving a notification from the first communication device to terminate the relay transmission to the other relay device, if the other communication device is carrying out a relay transmission to the other relay device, the relay connection established between the relay device and the other relay device is maintained. When none of the communication devices is carrying out a relay transmission to the other relay device, the holding unit disconnects the relay connection held with the other relay device.
  • According to another aspect of the present invention, a communication system for relaying data between terminals includes a first relay device that can carry out communication with a first communication device, a server device, and a second relay device that can carry out communication with the second communication device. The first relay device includes an accepting unit and a holding unit. The accepting unit accepts a relay transmission instruction of data designating the second relay device from the first communication device. When a relay connection is yet to be established with the second relay device, the holding unit inquires a status of the second relay device to the server device. When the second relay device is capable of accepting a connection, the holding unit dynamically establishes a relay connection with the second relay device and holds the established relay connection. When a relay connection is already established with the second relay device, the holding unit sets such relay connection to be shared with the first communication device. The first relay device relays data received from the first communication device to the second relay device, and the second relay device further relays the data to the second communication device.
  • The first communication device and the second communication device are respectively provided in different private networks. A connection request for a TCP connection cannot be carried out to the first communication device and the second communication device from an external network.
  • The relay device of the present invention inquires a status of another relay device to the server device. When the other relay device is capable of accepting a connection, the relay device carries out a connection request, and establishes and holds a relay connection with the other relay device. Therefore, a communication device, which can carry out communication with the relay device, can carry out communication via the private network with a communication device, which can carry out communication with the other relay device.
  • The relay device of the present invention can establish a relay connection with a plurality of relay devices, and hold the established relay connections. Therefore, when communication devices to which communication is to be carried out belong to different networks, a plurality of connections can be generated independently.
  • The relay device of the present invention can independently disconnect each of the relay connections being held with a plurality of the relay devices. Therefore, the relay device of the present invention can maintain only the connections that are necessary for communication, and resources can be utilized efficiently.
  • The relay device of the present invention accepts a relay transmission instruction designating the other relay device from the first communication device, and inquires a status of the other relay device to the server device. When the other relay device is capable of accepting a connection, the relay device dynamically establishes a relay connection with the other relay device and holds the established relay connection. Therefore, by carrying out a request designating a relay destination to the relay device of the present invention, a communication device, which can carry out communication with the relay device of the present invention, can carry out communication with a communication device, which can carry out communication with the other relay device. Since a connection is established between the relay devices according to a request from the communication device, a network of a communication destination can be selected and a connection can be established more dynamically.
  • When receiving a notification from the server device that the other relay device has become capable of accepting a connection, the relay device notifies a connection possible state to the first communication device. Accordingly, at a point of time when a preparation is completed at the relay destination, a relay transmission can be started immediately.
  • Only the data having the first communication device as a transmitter or a transmission destination is relayed over the relay connection held by the holding unit. Therefore, a terminal, which has carried out a connection request to the relay device, can exclusively use the established connection.
  • The relay device of the present invention accepts a relay transmission instruction designating another relay device from the first communication device. When a relay connection is already established between the relay device of the present invention and the other relay device, the relay device of the present invention sets the first communication device to share the already established relay connection. Therefore, by carrying out a request designating a relay destination to the relay device of the present invention, a communication device, which can carry out communication with the relay device of the present invention, can carry out communication with a communication device, which can carry out communication with the other relay device. When a relay connection is already established between the relay device of the present invention and the designated relay device, the already established relay connection is shared. Therefore, processing load for establishing a connection can be reduced, and resources can be saved.
  • When receiving a notification from the first communication device to terminate the relay transmission to the other relay device, if the other communication device is carrying out a relay transmission to the other relay device, the relay connection established with the other relay device is maintained. Accordingly, an end of communication of one communication device does not influence a communication of another communication device. A communication device sharing the relay connection can use the relay connection until the communication of the communication device itself is completed.
  • Other features, elements, processes, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the present invention with reference to the attached drawings.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • FIG. 1 illustrates a configuration of a communication system according to a first preferred embodiment of the present invention.
  • FIG. 2 illustrates a registration example of a relay device database.
  • FIG. 3 is a flowchart illustrating a processing carried out in the communication system according to the first preferred embodiment of the present invention.
  • FIG. 4 is a flowchart illustrating a processing carried out in the communication system focusing on a relay device.
  • FIG. 5 is a flowchart illustrating a processing carried out in the communication system focusing on a relay device.
  • FIG. 6 illustrates an imaginary state in which a plurality of relay connections are established.
  • FIG. 7 illustrates a configuration of a communication system according to a second preferred embodiment of the present invention.
  • FIG. 8 illustrates a registration example of a relay connection database.
  • FIG. 9 is a flowchart illustrating a processing carried out in the communication system according to the second preferred embodiment of the present invention.
  • FIG. 10 is a flowchart illustrating a processing carried out in the communication system focusing on a relay device.
  • FIG. 11 is a flowchart illustrating a processing carried out in the communication system focusing on a relay device.
  • FIG. 12 illustrates a registration example of a relay connection database.
  • FIG. 13 is a flowchart illustrating a processing carried out in a communication system according to a third preferred embodiment of the present invention.
  • FIG. 14 is a flowchart illustrating a processing carried out in the communication system focusing on a relay device.
  • FIG. 15 is a flowchart illustrating a processing carried out in the communication system focusing on a relay device.
  • DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS First Preferred Embodiment
  • Preferred embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 illustrates a configuration of a communication system according to a first preferred embodiment. In the communication system of the first preferred embodiment, two Local Area Networks (LANs) 10 and 20 are connected via a Wide Area Network (WAN) 30. For example, the LANs 10 and 20 are an in-house LAN of a company, and the WAN 30 is a public network such as the Internet. That is, two different private LANs 10 and 20 are connected via a public network such as the Internet.
  • As illustrated in FIG. 1, two communication devices 11 and 12 and a relay device 15 are connected in the LAN 10. The LAN 10 is connected to the WAN 30 via a gateway (GW) 16. Two communication devices 21 and 22 and a relay device 25 are connected in the LAN 20. The LAN 20 is connected to the WAN 30 via a gateway 26.
  • The communication devices 11 and 12 are terminals such as personal computers, and include a network function. Specifically, each of the communication devices 11 and 12 includes a Transmission Control Protocol/Internet Protocol (TCP/IP), and uses the TCP/IP to carry out communication with the relay device 15 and other computers or the like connected to the LAN 10. In the same manner, each of the communication devices 21 and 22 includes a TCP/IP, and uses the TCP/IP to carry out communication with the relay device 25 and other computers or the like connected to the LAN 20. The relay devices 15 and 25 and the gateways 16 and 26 can also carry out communication by the TCP/IP.
  • A server device 35 is connected to the WAN 30. As described above, the WAN 30 is a public network such as the Internet. Therefore, a terminal connected to the LAN 10, the LAN 20, or the WAN 30 can establish a TCP connection by designating a global IP address of the server device 35.
  • A private IP address is assigned to the communication devices 11 and 12 and the relay device 15 connected to the LAN 10 and the communication devices 21 and 22 and the relay device 25 connected to the LAN 20. The gateways 16 and 26 function as a firewall, and a connection cannot be established directly from an external network by designating a terminal located inside of the network. Therefore, a terminal or the like connected to the WAN 30 has restrictions when carrying out a TCP connection request to the relay device 15 or 25. In the first preferred embodiment, since the server device 35 functions as a Session Initiation Protocol (SIP) server (a proxy server and a registered server of the SIP) as to be described hereinafter, the gateways 16 and 26 are set such that communication designating a specific port corresponding to the relay servers 15 and 25 can be carried out to the gateways 16 and 26, respectively.
  • FIG. 2 illustrates a registration example of a relay device database 351 managed by the server device 35. In the example illustrated in FIG. 2, three relay devices A, B, and C are registered. The relay devices A, B, and C are device names that are assigned to the relay device 15 or the relay device 25, for example. Flags of a Uniform Resource Locator (URL), an IP address, and a login status are set for each of the relay devices A, B, and C.
  • An IP address of each of the relay devices registered in the relay device database 351 is not an IP address in a private network, but is a global IP address converted by a gateway by a function such as a Network Address Translation (NAT) or an IP masquerade. For example, the relay device 15 is assigned with a private address in the LAN 10. When the relay device 15 accesses the server device 35, the IP address assigned to the relay device 15 is converted into a global IP address by the gateway 16.
  • Each of the relay devices A through C establishes a connection with the server device 35, and logs into the server device 35. A “status” field of the relay device database 351 stores information indicating whether each of the relay devices A through C is currently under a logged-in status or a logged-out status with respect to the server device 35. When each of the relay devices is under a logged-in status, the server device 35 determines that a TCP connection is prepared to be established between the logged-in relay devices. In other words, a status in which the relay device is logged in the server device 35 indicates a status in which the relay device is capable of accepting a TCP connection request transmitted from another terminal.
  • With reference to FIG. 3 through FIG. 5, a description will be made of a flow of a communication processing in the above-described communication system. FIG. 3 illustrates a flow of the processing of the entire communication system including the relay devices 15 and 25 and the server device 35. Further, in the following description, a Session Initiation Protocol (SIP) is used for communication between the relay device 15 and the server device 35, and between the relay device 25 and the server device 35. However, other protocols may also be used.
  • Each of the relay devices 15 and 25 transmits a “REGISTER request message” of the SIP to the server device 35 at initialization or periodically to notify position information (for example, an IP address, and/or a port number) of the relay device to the server device 35. The server device 35 manages the relay device database 351 illustrated in FIG. 2 according to the notified position information. The server device 35 can carry out communication with each of the relay devices over the gateway according to the position information. In FIG. 3, under an initial state, the relay device 15 and the relay device 25 are logged in the server device 35. First, the relay device 25 notifies logout status information to the server device 35 (step S101), and the server device 35 responds to the notification (step S102). The server device 35 executes a logout processing of the relay device 25, and updates the “status” field of the relay device 25 in the relay device database 351 to “logout”.
  • Under this state, when the relay device 15 carries out a notification request of the status information to the server device 35 (step S103), the server device 35 carries out a response (step S104), and notifies that the relay device 25 is logged-out (step S105). The relay device 15 responds to this notification (step S106).
  • Next, the relay device 25 notifies login status information to the server device 35 (step S107), and the server device 35 responds to the notification (step S108). The server device 35 executes the login processing of the relay device 25, and updates the “status” field of the relay device database 351 to “login”. Furthermore, the server device 35 notifies the relay device 15 that the relay device 25 has logged in (step S109). The relay device 15 responds to this notification (step S110).
  • When the relay device 15 receives a notification that the relay device 25 has logged in, the relay device 15 transmits a connection request for the relay device 25 to the server device 35 (step S111). As illustrated in FIG. 3, this connection request is an “INVITE request message” of the SIP, and includes TCP connection information in a body portion following a blank line. In the illustrated example, the connection request includes an IP address (200.1.1.1) and a TCP port number (6109) or the like of the relay device 15 (transmitter). The server device 35 relays the connection request to the relay device 25 (step S112). The relay device 25, which has received the connection request, transmits a response to the server device 35 to permit a connection (step S113). As illustrated in FIG. 3, this response is “200 OK response message” of the SIP, and includes TCP connection information in a body portion following a blank line. In the illustrated example, the response includes an IP address (200.2.2.2) and a TCP port number (7109) or the like of the relay device 25 (transmitter). The server device 35 relays the response to the relay device 15 (step S114). As described above, the relay device 15 and the relay device 25 use the INVITE request and the OK response of the SIP to exchange TCP connection information, and carry out a negotiation for establishing a TCP connection. When the relay device 15 receives the response, the relay device 15 transmits a TCP connection request to the relay device 25 (step S115). Accordingly, a TCP connection is established between the relay device 15 and the relay device 25.
  • The above-described processing is executed by a network administrator of the LAN 10 or the LAN 20, for example. That is, in order to prepare such that a connection with another LAN can be carried out dynamically, a relay device in a network is logged into the server device 35 by the network administrator as illustrated at step S107. Accordingly, a preparation is completed for receiving a TCP connection request from another relay device. When the network administrator wishes to carry out a connection with another LAN, the network administrator accesses the server device 35, and acquires status of a destination relay device. When the network administrator learns that the destination relay device is under a logged-in status, the network administrator transmits a connection request to the server device 35.
  • That is, in the present preferred embodiment, the relay device 15 transmits an INVITE request of the SIP via the server device 35 to establish a TCP connection (media session) for relaying. In other words, since a relay channel as a media session is generated by a call control protocol, a relay communication channel can be established dynamically.
  • When a TCP connection is established between the relay device 15 and the relay device 25 as described above, the relay device 15 and the relay device 25 hold the established TCP connection. When the relay device 15 receives data from the communication device 11, 12 or the like to be transmitted to the communication device 21, 22 or the like, the relay device 15 relays the received data to the relay device 25 (step S116). The relay device 25 further relays the relayed data to the communication device 21, 22 or the like. Data transmitted from the communication device 21, 22 or the like is also relayed to the communication device 11, 12, or the like via the relay device 25 and the relay device 15 (step S117).
  • Further, in order to carry out communication between the LAN 10 and the LAN 20 via the WAN 30, each of the relay devices 15 and 25 manages a list of device names of communication devices connected to each of the LANs 10 and 20, respectively. When a TCP connection is established between the relay device 15 and the relay device 25, the relay device 15 and the relay device 25 exchange the list. When carrying out communication between a communication device connected to the LAN 10 and a communication device connected to the LAN 20, a device name of a relay device of a LAN of a transmission destination and a device name of a communication device of the transmission destination are designated. That is, since a unique device name (registered in the relay device database 351) is assigned to a relay device using such a communication system, by designating both the device name of the relay device and the device name of the communication device, the communication device of the transmission destination can be identified uniquely. For example, a name such as “communication device name@relay device name” may be used. Each relay device knows an association between a communication device name and an IP address for a communication device connected to the LAN to which the relay device itself is also connected. Therefore, the relay device can relay data to a communication device designated by “communication device name@relay device name”.
  • When transmission and reception of data between the communication devices end and the connection established between the relay device 15 and the relay device 25 becomes unnecessary, the network administrator disconnects the connection. First, the relay device 15 transmits a disconnection request for the relay device 25 to the server device 35 (step S118). The server device 35 relays the disconnection request to the relay device 25 (step S119). A response from the relay device 25 is transmitted to the server device 35 (step S120), and relayed to the relay device 15 (step S121).
  • FIG. 4 is a flowchart focusing on a processing carried out by the relay device 15 in the processing described with reference to FIG. 3. First, the relay device 15 transmits a starting request for starting a relay connection to the server device 35 (step S201). The relay-device 25 is designated as the relay destination in the starting request. When a fact that the relay device 25 of the relay destination is logged out becomes apparent from the response from the server device 35 (step S202: NO), the relay device 15 stands by until receiving a login notification (step S203). When receiving a login notification (step S203: YES), the process proceeds onto step S204.
  • When a determination is made at step S202 that the relay device 25 of the relay destination is logged in, the relay device 15 generates TCP connection information (step S204), and transmits a connection request (step S205). Then, the relay device 15 stands by for a response from the relay device 25 (step S206). When receiving a response (step S206: YES), the relay device 15 analyzes the TCP connection information included in the received response (step S207). That is, the relay device 15 acquires port number information or the like included in the response transmitted from the relay device 25. Then, the relay device 15 carries out a TCP connection with the relay device 25 (step S208).
  • Under a state in which a TCP connection is established and held, when the communication device 11 or the like transmits relay data (step S209: YES), the relay device 15 relays the data to the communication device 21 or the like (step S210). When the relay device 15 receives relay data to be relayed to the communication device 11 or the like (step S211: YES), the relay device 15 relays the data to the communication device 11 or the like of the relay destination (step S212). When the relay device 15 receives a disconnection request from the relay device 25 (step S213: YES), the relay device 15 transmits a response (step S214) and disconnects the TCP connection (step S215).
  • When a disconnection request is carried out by a network administrator of the LAN 10 (step S216: YES), the relay device 15 transmits a disconnection request to the relay device 25 (step S217). When the relay device 15 receives a response (step S218: YES), the relay device 15 disconnects the TCP connection (step S219).
  • FIG. 5 is a flowchart focusing on a processing carried out by the relay device 25 in the processing described with reference to FIG. 3. First, a network administrator of the LAN 20 determines whether or not to prepare for establishing a connection with another LAN. When preparing for establishing a connection with another LAN, an operation is performed for validating a relay function of the relay device 25. When the relay function is validated (step S301: YES), the relay device 25 transmits a login command to the server device 35 (step S302). Then, the relay device 25 receives a response from the server device 35 (step S303), and a processing for validating the relay function is completed.
  • As described above, when the relay device 25 of the relay destination is under a logged-in status, that is, when the relay device 25 is capable of accepting a connection, the relay device 15 dynamically establishes a TCP connection with the relay device 25. Accordingly, data can be transmitted and received via the WAN 30 such as the Internet. For example, in case of a headquarter office and a branch office of a company where traffic constantly generates stably, LANs may be connected fixedly by using the conventionally used VPN. Meanwhile, when carrying out data communication by establishing connections with different networks via the WAN 30 under any timing, the communication system of the present preferred embodiment can be used.
  • According to the communication system of the present preferred embodiment, when a connection environment (an IP address and/or a port number) of the relay device of the other party is changed, the relay device carries out a negotiation first (steps S111 through S114). Therefore, a connection for relaying data can be established reliably.
  • The relay devices 15 and 25 of the present preferred embodiment can establish a TCP connection with a plurality of relay devices. For example, as illustrated in FIG. 6, the relay device 15 can establish a separate TCP connection with each of three relay devices 25, 45 and 55. A method for establishing a TCP connection with the relay devices 45 and 55 is the same as the processing carried out with respect to the relay device 25. Each of the relay devices 15 and 25 or the like establishes a TCP connection with a plurality of relay devices, and relays data to the plurality of the relay devices. In an example illustrated in FIG. 6, the relay device 15 relays data transmitted from a certain communication device to the relay device 45, and relays data transmitted from another communication device to the relay device 55.
  • A method for disconnecting the TCP connection established with each of the relay devices 45 and 55 is also the same as the processing carried out with respect to the relay device 25. That is, a TCP connection can be established independently with each of the plurality of the relay devices 25, 45, and 55, and the TCP connection can be disconnected independently.
  • Conventionally, in the VPN or the like, when a plurality of LANs are connected, the plurality of the LANs are connected as one VPN. Meanwhile, according to the communication system of the present preferred embodiment, a connection is established independently with just a relay device to which a communication is to be carried out, and a connection established with a relay device to which a communication is no longer necessary to be carried out can be disconnected independently. Therefore, efficient communication system can be constituted without consuming unnecessary resources.
  • Second Preferred Embodiment
  • Next, a second preferred embodiment of the present invention will be described. In the first preferred embodiment, a connection is established dynamically between relay devices according to an instruction from a network administrator. In the second preferred embodiment, a connection is established between relay devices according to a designation from a communication device. Specifically, in the first preferred embodiment, by predicting a status of communication to be generated between the communication devices, a network administrator carries out an operation for establishing or disconnecting a connection between the relay devices. Meanwhile, in the second preferred embodiment, a control is carried out to establish or disconnect a connection between the relay devices more dynamically according to a communication processing that generates from a communication device. In the following description, a description that is the same as the first preferred embodiment will be omitted.
  • FIG. 7 illustrates an example of a configuration of a communication system according to the second preferred embodiment of the present invention. In FIG. 7, a LAN 40 is added to the system configuration illustrated in FIG. 1. The basic system configuration illustrated in FIG. 7 is the same as the first preferred embodiment. A communication device 41 and a relay device 45 are connected to the LAN 40, and the LAN 40 is connected to a WAN 30 via a gateway 46.
  • The relay devices 15, 25, and 45 include relay connection databases 151, 251, and 451, respectively. FIG. 8 illustrates an example of registration of the relay connection database 151 stored in the relay device 15.
  • The relay connection database 151 is a database for managing a TCP connection currently established by the relay device 15. A “client” field stores a setting of a device name of a communication device that has requested a connection to be established with a relay device (hereinafter referred to as a “requesting communication device”). For example, “ClientX” and “ClientY” in FIG. 8 are a device name assigned to the communication device 11, 21 or the like. “Relay destination URL” and “IP address” fields store a setting of a URL and an IP address of a relay device of a relay destination, respectively. “Connection number” field stores a setting of a port number of a generated TCP connection. “Generated time” field stores a setting of time when a TCP connection has been established.
  • In the present preferred embodiment, according to a designation from the requesting communication device, a TCP connection is established with a relay device of a communication destination. However, a device that can use such a TCP connection for carrying out communication is only the requesting communication device. That is, as illustrated in FIG. 8, one-to-one relation is established for a communication device and a TCP connection.
  • The contents of the relay connection databases 251 and 451 are the same as the relay connection databases 151 illustrated in FIG. 8. The relay connection databases 251 and 451 include registration of a status of a TCP connection currently established by the relay devices 25 and 45, respectively.
  • Next, with reference to FIG. 9 through FIG. 11, a description will be made of a flow of a communication processing carried out in the above-described communication system. FIG. 9 illustrates a flow of the processing of the entire communication system including the communication devices 11 and 12, the relay devices 15 and 25, and the server device 35. Further, in the following description, a description will be made of an example in which the SIP is used for the communication between the relay devices 15 and the server device 35 and between the server device 35 and the relay device 25. However, other protocols may also be used.
  • In the same manner as in the first preferred embodiment, each of the relay devices 15 and 25 transmits a “REGISTER request message” of the SIP to the server device 35 at initialization or periodically to notify position information (for example, an IP address and/or a port number) of the relay device to the server device 35. In FIG. 9, under an initial state, the relay device 15 and the relay device 25 are logged in the server device 35. First, the relay device 25 notifies logout status information to the server device 35 (step S401), and the server device 35 responds to the notified logout status information (step S402). The server device 35 executes a logout processing of the relay device 25, and updates the “status” field of the relay device 25 in the relay device database 351 to “logout”.
  • Under this state, the communication device 11 transmits a relay transmission request of data and a status confirmation request, which designate the relay device 25, to the relay device 15 (step S403). When the relay device 15 carries out a notification request of the status information to the server device 35 (step S404), the server device 35 carries out a response (step S405) and notifies the relay device 15 that the relay device 25 is logged out (step S406). The relay device 15 responds to the notification (step S407). Furthermore, the relay device 15 notifies the communication device 11 that the relay device 25 is a logged out (step S408). Accordingly, the communication device 11 stands by until the relay device 25 logs in.
  • Next, the relay device 25 notifies login status information to the server device 35 (step S409), and the server device 35 responds to the notified login status information (step S410). The server device 35 executes a login processing of the relay device 25, and updates the “status” field of the relay device database 351 to “login”. The server device 35 also notifies the relay device 15 that the relay device 25 has logged in (step S411). The relay device 15 responds to the notification (step S412). Furthermore, the relay device 15 notifies the communication device 11 that the relay device 25 has logged in (step S413).
  • When the communication device 11, which has been on standby, receives the notification carried out at step S413, the communication device 11 carries out a relay transmission request again designating the relay device 25 (step S414). Further, in the second preferred embodiment, the communication device 11 is provided to standby until receiving a notification that the relay device 25 has logged in. However, as another preferred embodiment, without standing by for such a notification, the communication device 11 may periodically transmit a relay transmission request to the relay device 15.
  • When the relay device 15 receives the relay transmission request from the communication device 11, the relay device 15 transmits a connection request for the relay device 25 to the server device 35 (step S415). As described in the first preferred embodiment, the connection request is an “INVITE request message” of the SIP, and includes TCP connection information. The server device 35 relays the connection request to the relay device 25 (step S416). When receiving the connection request, the relay device 25 transmits a response to the server device 25 to permit a connection (step S417). As described in the first preferred embodiment, the response is “200 OK response message” of the SIP, and includes TCP connection information. The server device 35 relays the response to the relay device 15 (step S418). The relay device 15 and the relay device 25 exchange the TCP connection information as described above. When receiving the response, the relay device 15 transmits a TCP connection request to the relay device 25 (step S419). Accordingly, a TCP connection is established between the relay device 15 and the relay device 25.
  • The above-described processing is carried out dynamically, for example, when a communication processing from the communication device 11 to the communication device 21 generates. That is, the relay devices are not connected fixedly, but a connection is carried out when traffic generates. However, in order to prepare for a connection request from a relay device of another end, a network administrator is required to be prepared by logging a relay device within a network into the server device 35 as illustrated at step S409.
  • In the present preferred embodiment, the relay device 15 receives an instruction from the communication device 11, and the relay device 15 transmits an INVITE request of the SIP via the server device 35 to establish a relay TCP connection (media session). That is, at a point of time when a connection request from a communication device generates, since a relay channel as a media session is generated by a call control protocol, a relay communication channel can be established dynamically.
  • When a TCP connection is established between the relay device 15 and the relay device 25 as described above, the relay device 15 and the relay device 25 hold the established TCP connection. When the communication device 11 transmits data addressed to the communication device 21, 22 or the like (step S421), the relay device 15 relays the data to the relay device 25 (step S422). The relay device 25 further relays the relayed data to the communication device 21, 22 or the like. The data transmitted from the communication device 21, 22 or the like is relayed to the relay device 15 via the relay device 25 in the same manner (step S423) and relayed further to the communication device 11 via the relay device 15 (step S424).
  • When a relay transmission using the relay device 25 is completed, the communication device 11 transmits a disconnection instruction to the relay device 15 (step S425). The relay device 15 transmits a disconnection request for the relay device 25 to the server device 35 (step S426). The server device 35 relays the received disconnection request to the relay device 25 (step S427). A response from the relay device 25 is transmitted to the server device 35 (step S428) and relayed to the relay device 15 (step S429). Accordingly, the TCP connection between the relay device 15 and the relay device 25 is disconnected, and the relay device 15 notifies the communication device 11 that the TCP connection has been disconnected (step S430).
  • Under such a state, when another communication device 12 carries out a relay transmission request designating the relay device 25 again (step S431), a connection request is transmitted from the relay device 15 to the server device 35 (step S432). At this point of time, when the relay device 25 is under a logged-out status, the server device 35 notifies the logged-out status (step S433), and the communication device 12 is notified that the relay device 25 is under a logged-out status. In the same manner as the processing carried out by the communication device 11, when the relay device 25 logs in, the communication device 12 carries out a relay transmission request to the relay device 25 again. Accordingly, a TCP connection is established between the relay device 15 and the relay device 25.
  • FIG. 10 is a flowchart focusing on a processing carried out by the relay device 15 in the processing described with reference to FIG. 9. First, the relay device 15 confirms whether or not a relay instruction from the communication device 11, 12 or the like is generated (step S501). When a relay instruction is generated (step S501: YES), the relay device 15 confirms whether or not a status monitoring instruction is generated (step S502). When the status monitoring instruction is generated, the relay device 15 checks whether or not the relay device of the relay destination is logged in (step S503). When the relay device 15 confirms that the relay device of the relay destination is logged out (step S503: NO), the relay device 15 stands by until receiving a login notification (step S504).
  • When receiving a notification from the server device 35 indicating that the relay device of the relay destination has logged in (stepS504: YES), the relay device 15 notifies the requesting communication device that the relay destination has logged in (step S505). Then, the relay device 15 stands by until receiving a relay instruction from the communication device 11, 12 or the like again (step S506). When the relay device 15 receives a relay instruction, the process proceeds onto step S508. When a determination is made at step S503 that the relay device of the relay destination is logged in, the process proceeds immediately onto step S508. When a status monitoring instruction is not included in the request from the communication device (step S502: NO), if the relay destination is logged in (step S507: YES), the process proceeds onto step S508. If the relay destination is not logged in, the process returns to step S502 and the processing is repeated. That is, when a status monitoring instruction has been received from a requesting communication device, the relay device 15 monitors the relay device of the relay destination until the relay device of the relay destination logs in. When receiving a notification that the relay device of the relay destination has logged in, the relay device 15 notifies such information also to the requesting communication device.
  • Next, the relay device 15 generates TCP connection information (step S508) and transmits a connection request (step S509). The relay device 15 stands by until receiving a response from the relay device 25 (step S510). When not receiving a response (step S510: NO), the relay device 15 carries out an error notification to the requesting communication device (step S511). The process returns to step S501 and the processing is repeated. When receiving a response (step S510: YES), the relay device 15 analyzes the TCP connection information included in the received response (step S512). That is, the relay device 15 acquires port number information or the like included in the response transmitted from the relay device 25. Then, the relay device 15 carries out a TCP connection to the relay device 25 (step S513). The relay device 15 notifies the requesting communication device that a connection has been established with the relay destination (step S514). Then, the relay device 15 registers information of the newly established TCP connection in the relay connection database 151 (step S515).
  • Under a state in which the TCP connection is established and held, in the flowchart of FIG. 11, when relay data is transmitted from the communication device 11 or the like (step S516: YES), the relay device 15 relays the data to the communication device 21 or the like (step S517). When receiving relay data to be relayed to the communication device 11 or the like (step S518: YES), the relay device 15 relays the data to the communication device 11 or the like of the relay destination (step S519). When receiving a disconnection request from the relay device 25 (step S520: YES), the relay device 15 transmits a response (step S521) and disconnects the TCP connection (step S522). When a disconnection request is carried out by the requesting communication device (step S523: YES), the relay device 15 transmits a disconnection request to the relay device 25 of the relay destination (step S524). When receiving a response (step S525: YES), the relay device 15 disconnects the TCP connection (step S526). Then, the relay device 15 notifies the requesting communication device that a connection with the relay destination has been disconnected (step S527), and the information of the TCP connection registered in the relay connection database 151 is deleted (step S528).
  • As described above, according to the second preferred embodiment, when a relay instruction from a communication device generates, a TCP connection is established dynamically with the relay device of the relay destination, and communication can be carried out between private networks. Unlike the conventional VPN or the like that is fixedly set, when a request of communication generates, a connection necessary for such communication is established. Therefore, resources can be utilized efficiently.
  • According to the second preferred embodiment, when a communication connection is established according to a request from a certain communication device, only such a requesting communication device is permitted to use the established communication connection. For example, when a request of communication generates from the communication device 11 to the communication device 21, a TCP connection is established between the relay device 15 and the relay device 25 according to the request. The established TCP connection is used only for the communication between the communication device 11 and the communication device 21. In other words, the relay device 15 and the relay device 25 use the TCP connection just for relaying the data transmitted and received between the communication device 11 and the communication device 21. Therefore, a connection established according to a request from a certain communication device is used exclusively by such a communication device.
  • In the example illustrated in FIG. 7, under a state in which a connection is established between the relay device 15 and the relay device 25 according to a request from the communication device 11, suppose that a connection is established further between the relay device 15 and the relay device 45 according to a request from the communication device 12. In this case, a description has been made with reference to FIG. 6 that an individual data relay connection is established. Therefore, the communication device 11 and the communication device 12 use different TCP connections for relaying data. Meanwhile, under a state in which the communication device 11 is carrying out a relay transmission designating the relay device 25, when the communication device 12 also carries out a relay instruction designating the same relay device 25, since the already established TCP connection is used exclusively by the communication device 11, a separate communication connection is established.
  • Third Preferred Embodiment
  • Next, a description will be made of a third preferred embodiment of the present invention. Also in the third preferred embodiment, in the same manner as in the second preferred embodiment, a connection is carried out between relay devices according to a request from a communication device. However, in the third preferred embodiment, when a connection has already been established between the relay devices, another communication device shares the already established connection. This feature differs from the second preferred embodiment. In the following, a description will be made primarily of aspects that are different from the second preferred embodiment.
  • FIG. 12 illustrates an example of registration of the relay connection database 151 stored in the relay device 15. As illustrated in FIG. 12, a plurality of clients (communication devices) are associated with one TCP connection. In the example illustrated in FIG. 12, a relay transmission request has generated from two communication devices (ClientX and ClientY), and both of the communication devices designate the same relay device (Relayserver1@sample.net). Therefore, the two communication devices are sharing a TCP connection with a connection number 49583.
  • The contents of the relay connection databases 251 and 451 stored in the relay devices 25 and 45, respectively, are the same as the relay connection database 151 illustrated in FIG. 12. The relay connection databases 251 and 451 store a status of a TCP connection currently established by the relay devices 25 and 45, respectively.
  • Next, with reference to FIG. 13 through FIG. 15, a description will be made of a flow of a communication processing carried out in the above-described communication system. FIG. 13 illustrates a flow of a processing of the entire communication system including the communication devices 11 and 12, the relay devices 15 and 25, and the server device 35. Further, in the following description, a description will be made of an example in which the SIP is used for the communication between the relay device 15 and the server device 35, and between the server device 35 and the relay device 25. However, other protocols may also be used.
  • The processing from step S701 to step S724 in FIG. 13 corresponds to the processing from step S401 to step S424 in FIG. 9. Since the processing is the same, a description will be omitted. That is, the communication device 11 generates a relay transmission request designating the relay device 25, and a TCP connection is established between the relay device 15 and the relay device 25. Then, data is transmitted and received between the communication device 11 and the communication device 21 or the like.
  • Under such a state, a different communication device 12 carries out a relay transmission request designating the relay device 25 again (step S725). Since the TCP connection is currently being established between the relay device 15 and the relay device 25, the relay device 15 notifies the communication device 12 that a relay transmission of the data can be carried out (step S726). Accordingly, when data is transmitted from the communication device 12 (step S727), the relay device 15 uses the already established TCP connection to relay the data transmitted from the communication device 12 to the relay device 25 (step S728). The relay device 25 also uses the already established TCP connection for relaying the data, which has been transmitted from the communication device 21 or the like to the communication device 12, to the relay device 15 (step S729). The relay device 15 further transmits the received data to the communication device 12 (step S730).
  • As described above, in the third preferred embodiment, a TCP connection is already established between the relay devices, and when the already established TCP connection can be used for a newly generated relay transmission request, a new TCP connection is not established. A plurality of communication terminals share the same TCP connection. Accordingly, load required for establishing a TCP connection can be reduced, and communication between different networks can be carried out under higher speed. In addition, resources of the relay device can be saved. For example, when carrying out communication via the Internet between a plurality of communication terminals connected to the LAN 10 and a plurality of communication terminals connected to the LAN 20, an increase in the processing speed and saving of the resources are possible and efficient. The above-described third preferred embodiment is also efficient when data volume to be relayed from one communication device is small.
  • Under a state in which the communication device 11 and the communication device 12 are sharing the TCP connection and carrying out data communication as described above, the communication device 11 transmits a disconnection instruction to the relay device 15 (step S731). Since the communication device 12 is using the same TCP connection, the relay device 15 does not carry out a processing in particular with respect to the disconnection instruction of step S731, and just carries out a response (step S732).
  • Then, when the relay transmission using the relay device 25 ends, the communication device 12 transmits a disconnection instruction to the relay device 15 (step S733). Since the relay device 15 has already received the disconnection instruction from the communication device 11, the relay device 15 can determine that the shared TCP connection has become unnecessary. Therefore, the relay device 15 transmits a disconnection request for the relay device 25 to the server device 35 (step S734). The server device 35 relays the disconnection request to the relay device 25 (step S735). The relay device 25 transmits a response to the server device 35 (step S736). Then, the server device 35 relays the response to the relay device 15 (step S737). Accordingly, the TCP connection between the relay device 15 and the relay device 25 is disconnected, and the relay device 15 notifies the communication device 11 that the TCP connection has been disconnected (step S738).
  • FIG. 14 is a flowchart focusing on a processing carried out by the relay device 15 in the processing described with reference to FIG. 13. First, the relay device 15 confirms whether or not a relay instruction from the communication device 11 or 12 or the like has generated (step S801). When a relay instruction has generated (step S801: YES), the relay device 15 confirms whether or not a TCP connection is already established with a relay device of a relay destination (step S802). That is, the relay device 15 confirms whether or not the same relay device has already been designated by another communication device and a communication is being carried out with such a relay device.
  • When a connection is already established with the already instructed relay destination (step S802: YES), the relay device 15 notifies that data can be relayed to a requesting communication device (step S815). Then, the relay device 15 updates the information of the relay connection database 151 (step S816). That is, since information regarding the TCP connection is already registered in the relay connection database 151, the relay device 15 just adds a client (communication device). In the example illustrated in FIG. 12, for example, when ClientX and a TCP connection with a connection number 49583 are associated and stored, the relay device 15 carries out a processing for adding ClientY to the “client” field of such record.
  • When a connection is yet to be established with the designated relay destination at step S802, the relay device 15 executes the processing from step S803 to step S814. This processing corresponds to the processing from step S502 to step S513 in FIG. 10. Since the processing is the same, a description will be omitted.
  • Next, a description will be made with reference to FIG. 15. Under a state in which a TCP connection is established and held, when relay data is transmitted from the communication device 11 or the like (step S817: YES), the data is relayed to the communication device 21 or the like (step S818). When receiving relay data to be relayed to the communication device 11 or the like (step S819: YES), the relay device 15 relays the data to the communication device 11 or the like of the relay destination (step S820). When receiving a disconnection request from the relay device 25 of the relay destination (step S821: YES), the relay device 15 transmits a response (step S822) and disconnects the TCP connection (step S823). As described above, when the TCP connection is disconnected from the relay device 25 of the relay destination, the relay device 15 notifies the communication device to which relay transmission is being carried out that the connection with the relay destination has been disconnected to (step S824). When the disconnected TCP connection had been shared among a plurality of communication devices, the disconnection is notified to all of the communication devices (steps S824 and S825).
  • When a disconnection request is carried out by the requesting communication device (step S826: YES), the relay device 15 checks whether or not the TCP connection instructed to be disconnected is being shared with another communication device (step S827). When such a TCP connection is being shared with another communication device (step S827: YES), without disconnecting the TCP connection, a formal disconnection notification is carried out to the communication device that has carried out the disconnection instruction (step S828). Then, the relay device 15 updates the information stored in the relay connection database 151 (stepS829). That is, the relay device 15 deletes information of the client (communication device) that has requested the disconnection instruction from the information of the shared TCP connection. The relay device 15 manages a currently established TCP connection and communication devices sharing the TCP connection at all times as described above.
  • When the TCP connection instructed to be disconnected is not shared with another communication device (step S827: NO), the relay device 15 transmits a disconnection request to the relay device 25 (step S830). When receiving a response (step S831: YES), the TCP connection is disconnected (step S832). Then, the relay device 15 notifies the requesting communication device that the connection with the relay destination has been disconnected (step S833) and deletes the information of the TCP connection registered in the relay connection database 151 (step S834).
  • As described above, according to the third preferred embodiment, when a relay instruction from a communication device generates, a TCP connection is dynamically established with a relay device of a relay destination, and communication can be carried out between private networks. Furthermore, when a relay instruction generates, if a TCP connection is already established with the relay destination, the already established TCP connection is shared. Accordingly, speed of the processing is increased, and resources can be utilized efficiently.
  • While the present invention has been described with respect to preferred embodiments thereof, it will be apparent to those skilled in the art that the disclosed invention may be modified in numerous ways and may assume many embodiments other than those specifically set out and described above. Accordingly, the appended claims are intended to cover all modifications of the present invention that fall within the true spirit and scope of the present invention.

Claims (15)

1. A communication system in which data is relayed between terminals, the communication system comprising:
a first relay device which carries out communication with a first communication device;
a server device; and
a second relay device which carries out communication with a second communication device,
wherein the first relay device includes:
a holding unit which inquires a status of the second relay device to the server device, and when the second relay device is capable of accepting a connection, carries out a connection request to the second relay device and dynamically establishes a relay connection with the second relay device and holds the established relay connection, and
a relay unit which relays data received from the first communication device to the second relay device so that the second relay device further relays the data to the second communication device.
2. The communication system according to claim 1, wherein the first communication device and the second communication device are provided in different private networks, and a connection request for establishing a transmission control protocol connection cannot be carried out from an external network to the first communication device and the second communication device.
3. A relay device which can carry out communication with a first communication device and a server device, the relay device comprising:
a relay unit which relays data received from the first communication device to another relay device; and
a holding unit which inquires a status of the other relay device to the server device, and when the other relay device is capable of accepting a connection, carries out a connection request to the other relay device, dynamically establishes a relay connection with the other relay device and holds the established relay connection,
wherein the other relay device can carry out communication with a second communication device, and the relay unit relays the data received from the first communication device to the other relay device so that the data is further relayed to the second communication device.
4. The relay device according to claim 3, wherein the holding unit establishes and holds relay connections with a plurality of other relay devices, and the relay unit uses a plurality of the relay connections to relay the data to the plurality of the other relay devices.
5. The relay device according to claim 4, wherein the holding unit separately disconnects the relay connections held with the plurality of the other relay devices.
6. A communication system in which data is relayed between terminals, the communication system comprising:
a first relay device which can carry out communication with a first communication device;
a server device; and
a second relay device which can carry out communication with a second communication device,
wherein the first relay device includes:
an accepting unit which accepts a relay instruction of data designating the second relay device from the first communication device, and
a holding unit which inquires a status of the second relay device to the server device, and when the second relay device is capable of accepting a connection, carries out a connection request to the second relay device, dynamically establishes a relay connection with the second relay device, and holds the established relay connection,
wherein the first relay device relays the data received from the first communication device to the second relay device so that the second relay device further relays the data to the second communication device.
7. The communication system according to claim 6, wherein the first communication device and the second communication device are provided indifferent private networks, and a connection request for establishing a transmission control protocol connection cannot be carried out from an external network to the first communication device and the second communication device.
8. A relay device which can carry out communication with a first communication device, the relay device comprising:
an accepting unit which accepts a relay transmission instruction designating another relay device from the first communication device; and
a holding unit which inquires a status of the other relay device to the server device, and when the other relay device is capable of accepting a connection, carries out a connection request to the other relay device, dynamically establishes a relay connection with the other relay device and holds the established relay connection,
wherein the other relay device can carry out communication with a second communication device, and the relay device relays data received from the first communication device to the other relay device so that the data is further relayed to the second communication device.
9. The relay device according to claim 8, wherein when the other relay device is incapable of accepting a connection, the holding unit notifies a connection impossible state to the first communication device, and when the holding unit receives a notification from the server device that the other relay device can accept a connection, the holding unit notifies a connection possible-state to the first communication device.
10. The relay device according to claim 8, wherein only data having the first communication device as a transmitter or a transmission destination is relayed over the relay connection held by the holding unit.
11. The relay device according to claim 9, wherein only data having the first communication device as a transmitter or a transmission destination is relayed over the relay connection held by the holding unit.
12. A communication system in which data is relayed between terminals, the communication system comprising:
a first relay device which can carry out communication with a first communication device;
a server device; and
a second relay device which can carry out communication with a second communication device,
wherein the first relay device includes:
an accepting unit which accepts a relay transmission instruction of data designating the second relay device from the first communication device, and
a holding unit, when a relay connection is yet to be established with the second relay device, the holding unit inquires a status of the second relay device to the server device, and when the second relay device is capable of accepting a connection, the holding unit dynamically establishes a relay connection with the second relay device and holds the established relay connection, and when the relay connection is already established with the second relay device, the holding unit sets so that the first communication device shares the already established relay connection,
wherein the first relay device relays data received from the first communication device to the second relay device, and the second relay device further relays the data to the second communication device.
13. The communication system according to claim 12, wherein the first communication device and the second communication device are provided in different private networks, and a connection request for a transmission control protocol connection cannot be carried out from an external network to the first communication device and the second communication device.
14. A relay device, which can carry out communication with a first communication device, the relay device comprising:
an accepting unit which accepts a relay transmission instruction designating another relay device from the first communication device; and
a holding unit, when a relay connection is yet to be established with the other relay device, the holding unit inquires a status of the other relay device to a server device, and when the other relay device is capable of accepting a connection, the holding unit dynamically establishes a relay connection with the other relay device and holds the established relay connection, and when the relay connection is already established with the other relay device, the holding unit sets so that the first communication device shares the already established relay connection,
wherein the other relay device can carry out communication with the second communication device, and the relay device relays data received from the first communication device to the other relay device so that the data is further relayed to the second communication device.
15. The relay device according to claim 14, wherein when receiving a notification from the first communication device to terminate a relay transmission being carried out to the other relay device, in case another communication device is carrying out a relay transmission to the other relay device, the holding unit holds the relay connection with the other relay device, and in case none of other communication devices is carrying out a relay transmission to the other relay device, the holding unit disconnects the relay connection established with the other relay device.
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Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080063001A1 (en) * 2006-09-12 2008-03-13 Murata Machinery, Ltd. Relay-server
US20080091768A1 (en) * 2006-10-11 2008-04-17 Murata Machinery, Ltd File transfer server
US20080089349A1 (en) * 2006-10-11 2008-04-17 Murata Machinery, Ltd File server device
US20080137672A1 (en) * 2006-12-11 2008-06-12 Murata Machinery, Ltd. Relay server and relay communication system
US20080147825A1 (en) * 2006-12-19 2008-06-19 Murata Machinery, Ltd. Relay server and client terminal
US20080275953A1 (en) * 2007-05-02 2008-11-06 Murata Machinery, Ltd. Relay server and relay communication system
US20080275945A1 (en) * 2007-05-02 2008-11-06 Murata Machinery, Ltd. Relay server and relay communication system
US20080281981A1 (en) * 2007-05-09 2008-11-13 Murata Machinery, Ltd. Relay server and relay communication system
US20080288591A1 (en) * 2006-11-24 2008-11-20 Murata Machinery, Ltd. Relay server, relay communication system, and communication device
US20090164637A1 (en) * 2007-12-25 2009-06-25 Murata Machinery, Ltd. Relay server and relay communication system
US20090164636A1 (en) * 2007-12-25 2009-06-25 Murata Machinery, Ltd. Relay server and relay communication system
US20090172075A1 (en) * 2007-12-28 2009-07-02 Murata Machinery, Ltd. Relay server and relay communication system
US20090172166A1 (en) * 2007-12-27 2009-07-02 Murata Machinery, Ltd. Relay server and relay communication system
US20100085957A1 (en) * 2008-10-03 2010-04-08 Elias Mark A Methods and Apparatus to Form Secure Cross-Virtual Private Network Communications Sessions
US20100235497A1 (en) * 2009-03-11 2010-09-16 Canon Kabushiki Kaisha Information processing apparatus and communication processing method thereof
US20110161525A1 (en) * 2008-09-01 2011-06-30 Murata Machinery, Ltd. Relay server and relay communication system
US20110179167A1 (en) * 2008-09-05 2011-07-21 Murata Machinery, Ltd. Relay server, relay communication system, and communication apparatus
US20120166593A1 (en) * 2010-12-27 2012-06-28 Samsung Sds Co., Ltd. Data transmission system and method using relay server
US20130136130A1 (en) * 2011-11-30 2013-05-30 Murata Machinery, Ltd. Relay server and relay communication system
US8798082B2 (en) 2009-05-15 2014-08-05 Murata Machinery, Ltd. Relay communication system and first relay server
US20150312363A1 (en) * 2014-04-25 2015-10-29 Pravala Networks Inc. Using proxy devices as dynamic data relays
US20170012828A1 (en) * 2015-07-08 2017-01-12 Kabushiki Kaisha Toshiba Relay apparatus

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011063844A1 (en) 2009-11-26 2011-06-03 Telefonaktiebolaget Lm Ericsson (Publ) Method, system and network nodes for performing a sip transaction in a session initiation protocol based communications network
WO2016084429A1 (en) * 2014-11-26 2016-06-02 株式会社リコー Control system, communication terminal, control device, communication system, control method, and program
TWI595765B (en) * 2015-10-22 2017-08-11 財團法人工業技術研究院 Method and communication device for network address translation traversal
TWI699099B (en) * 2019-03-19 2020-07-11 中華電信股份有限公司 Processing system and method thereof for communication between single or cross-region service hosts
JP7338200B2 (en) * 2019-03-29 2023-09-05 村田機械株式会社 Maintenance method and maintenance server
JP2020170452A (en) * 2019-04-05 2020-10-15 村田機械株式会社 Maintenance method and maintenance server
US11159586B2 (en) * 2019-05-07 2021-10-26 Jive Communications, Inc. Dynamically controlling relay communication links during a communication session

Citations (88)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5224205A (en) * 1990-05-21 1993-06-29 International Business Machines Corp. Method of combining architecturally dissimilar computing networks into a single logical network
US5535375A (en) * 1992-04-20 1996-07-09 International Business Machines Corporation File manager for files shared by heterogeneous clients
US5848134A (en) * 1996-01-31 1998-12-08 Sony Corporation Method and apparatus for real-time information processing in a multi-media system
US5884312A (en) * 1997-02-28 1999-03-16 Electronic Data Systems Corporation System and method for securely accessing information from disparate data sources through a network
US6061796A (en) * 1997-08-26 2000-05-09 V-One Corporation Multi-access virtual private network
US6111883A (en) * 1996-07-12 2000-08-29 Hitachi, Ltd. Repeater and network system utilizing the same
US6145084A (en) * 1998-10-08 2000-11-07 Net I Trust Adaptive communication system enabling dissimilar devices to exchange information over a network
US6178427B1 (en) * 1998-05-07 2001-01-23 Platinum Technology Ip, Inc. Method of mirroring log datasets using both log file data and live log data including gaps between the two data logs
US6215877B1 (en) * 1998-03-20 2001-04-10 Fujitsu Limited Key management server, chat system terminal unit, chat system and recording medium
US6222536B1 (en) * 1996-12-30 2001-04-24 Korea Telecom Method and apparatus for providing a number of subscribers with on-line banking service employing a plurality of bank systems
US6226692B1 (en) * 1995-12-15 2001-05-01 Object Dynamics Corporation Method and system for constructing software components and systems as assemblies of independent parts
US6237023B1 (en) * 1996-06-14 2001-05-22 Canon Kabushiki Kaisha System for controlling the authority of a terminal capable of simultaneously operating a plurality of client softwares which transmit service requests
US20010044819A1 (en) * 1997-11-07 2001-11-22 International Business Machines Corporation Relay server for unsigned applets
US20010047414A1 (en) * 2000-05-29 2001-11-29 Yoon Ki J. Dedicated private network service method having backup and loads-balancing functions
US6336141B1 (en) * 1997-01-08 2002-01-01 Hitachi, Ltd. Method of collectively managing dispersive log, network system and relay computer for use in the same
US20020023143A1 (en) * 2000-04-11 2002-02-21 Stephenson Mark M. System and method for projecting content beyond firewalls
US20020029276A1 (en) * 2000-04-12 2002-03-07 Samuel Bendinelli Methods and systems for an extranet
US20020032616A1 (en) * 2000-08-22 2002-03-14 Kazunori Suzuki Relay server, relaying method and payment system
US20020056003A1 (en) * 2000-04-11 2002-05-09 Dinkar Goswami System and method for real-time multi-directional file-based data streaming editor
US20020073182A1 (en) * 2000-12-08 2002-06-13 Zakurdaev Maxim V. Method and apparatus for a smart DHCP relay
US20020095506A1 (en) * 2001-01-15 2002-07-18 Murata Kikai Kabushiki Kaisha Relay server, communication system and facsimile system
US20020118398A1 (en) * 2001-01-15 2002-08-29 Murata Kikai Kabushiki Kaisha Relay server, communication system and facsimile system
US20020143922A1 (en) * 2001-04-03 2002-10-03 Murata Kikai Kabushiki Kaisha Relay server and relay system
US20020143956A1 (en) * 2001-04-03 2002-10-03 Murata Kikai Kabushiki Kaisha Relay server
US20020143960A1 (en) * 2000-08-02 2002-10-03 Erez Goren Virtual network generation system and method
US20020143957A1 (en) * 2001-04-03 2002-10-03 Murata Kikai Kabushiki Kaisha Relay server, network device, communication system, and communication method
US20020143855A1 (en) * 2001-01-22 2002-10-03 Traversat Bernard A. Relay peers for extending peer availability in a peer-to-peer networking environment
US20020146002A1 (en) * 2001-04-10 2002-10-10 Takayuki Sato Network administration apparatus, network administrating program, network administrating method and computer network system
US20020156875A1 (en) * 2001-04-24 2002-10-24 Kuldipsingh Pabla Peer group name server
US20030021232A1 (en) * 2001-07-27 2003-01-30 Jerome Duplaix Scalable router
US20030055741A1 (en) * 2001-08-21 2003-03-20 Kabushiki Kaisha Toshiba Server for exchanging design information, method for exchanging design information, program for exchanging design information, buying method of special design product and selling method of special design product
US6538773B1 (en) * 1999-03-26 2003-03-25 International Business Machines Corporation Method and apparatus for rendering grayscales at a facsimile presentation device using a calibrated transform
US6546488B2 (en) * 1997-09-22 2003-04-08 Hughes Electronics Corporation Broadcast delivery of information to a personal computer for local storage and access
US6564261B1 (en) * 1999-05-10 2003-05-13 Telefonaktiebolaget Lm Ericsson (Publ) Distributed system to intelligently establish sessions between anonymous users over various networks
US20030097456A1 (en) * 2001-11-08 2003-05-22 Huh Mi Young Method for synchronizing registration information within intra-domain
US6594246B1 (en) * 1998-07-10 2003-07-15 Malibu Networks, Inc. IP-flow identification in a wireless point to multi-point transmission system
US6636513B1 (en) * 1995-09-06 2003-10-21 Fujitsu Limited Switching system
US6650631B1 (en) * 1997-03-11 2003-11-18 Verizon Services Corp. Public IP transport network
US20040068524A1 (en) * 2002-04-03 2004-04-08 Aboulhosn Amir L. Peer-to-peer file sharing
US20040073610A1 (en) * 2002-09-30 2004-04-15 Katsuhiko Terada Contents reproducing system
US20040083385A1 (en) * 2002-10-25 2004-04-29 Suhail Ahmed Dynamic network security apparatus and methods for network processors
US6754212B1 (en) * 1996-07-12 2004-06-22 Hitachi, Ltd. Repeater and network system utililzing the same
US6757365B1 (en) * 2000-10-16 2004-06-29 Tellme Networks, Inc. Instant messaging via telephone interfaces
US6765686B2 (en) * 1997-11-14 2004-07-20 Canon Kabushiki Kaisha Image processing apparatus, method of controlling same, and image processing system
US6766373B1 (en) * 2000-05-31 2004-07-20 International Business Machines Corporation Dynamic, seamless switching of a network session from one connection route to another
US20040162871A1 (en) * 2003-02-13 2004-08-19 Pabla Kuldipsingh A. Infrastructure for accessing a peer-to-peer network environment
US20040172395A1 (en) * 2003-02-28 2004-09-02 Microsoft Corporation Method to delay locking of server files on edit
US20040243703A1 (en) * 2003-04-14 2004-12-02 Nbt Technology, Inc. Cooperative proxy auto-discovery and connection interception
US20040255048A1 (en) * 2001-08-01 2004-12-16 Etai Lev Ran Virtual file-sharing network
US20040267939A1 (en) * 2003-06-30 2004-12-30 Hitachi, Ltd. Session control apparatus, software applied to session control apparatus, communication control method, and network system
US6889256B1 (en) * 1999-06-11 2005-05-03 Microsoft Corporation System and method for converting and reconverting between file system requests and access requests of a remote transfer protocol
US6898641B1 (en) * 2000-04-10 2005-05-24 Fujitsu Limited Network routing system and routing apparatus
US20050144289A1 (en) * 2003-12-03 2005-06-30 Hitachi, Ltd. Connection control system, connection control equipment and connection management equipment
US6950879B2 (en) * 2001-01-24 2005-09-27 Interland, Inc. Using virtual network address information during communications
US20050216523A1 (en) * 2004-03-26 2005-09-29 Akihiko Sakaguchi File management method in a distributed storage system
US20050281251A1 (en) * 2004-06-21 2005-12-22 Hitachi, Ltd. Session control system for hierarchical relaying processes
US20050287998A1 (en) * 2004-06-29 2005-12-29 Nec Corporation Conference assisting system and method
US6988199B2 (en) * 2000-07-07 2006-01-17 Message Secure Secure and reliable document delivery
US20060020695A1 (en) * 2001-12-20 2006-01-26 Microsoft Corporation Scaling and delivering distributed applications
US7000248B2 (en) * 2000-11-01 2006-02-14 Nec Corporation Virtual network and virtual network connection system
US20060083171A1 (en) * 2004-07-13 2006-04-20 Aruze Corporation Media communication apparatus and media communication program product
US20060101064A1 (en) * 2004-11-08 2006-05-11 Sharpcast, Inc. Method and apparatus for a file sharing and synchronization system
US20060117076A1 (en) * 2004-11-29 2006-06-01 Spencer William A Method for replication tracing
US20060149771A1 (en) * 2005-01-05 2006-07-06 Hitachi, Ltd. Information processing system and communication retry method
US20060187902A1 (en) * 2005-02-24 2006-08-24 Oliver Birch Method and apparatus for session initiation protocol application design, development, execution and integration
US20060206616A1 (en) * 2005-03-14 2006-09-14 Gridiron Software, Inc. Decentralized secure network login
US7110393B1 (en) * 2001-02-28 2006-09-19 3Com Corporation System and method for providing user mobility handling in a network telephony system
US7120927B1 (en) * 1999-06-09 2006-10-10 Siemens Communications, Inc. System and method for e-mail alias registration
US20060256771A1 (en) * 2005-05-12 2006-11-16 Yahoo! Inc. Proxy server for relaying VOIP messages
US20060259553A1 (en) * 2003-02-03 2006-11-16 Jun Kawakita Synchronization program
US20060282540A1 (en) * 2005-06-08 2006-12-14 Murata Kikai Kabushiki Kaisha File server device, communication management server device, and network system including the file server device and the communication management server device
US7152111B2 (en) * 2002-08-15 2006-12-19 Digi International Inc. Method and apparatus for a client connection manager
US20070019545A1 (en) * 2005-07-20 2007-01-25 Mci, Inc. Method and system for securing real-time media streams in support of interdomain traversal
US20070022477A1 (en) * 2001-01-18 2007-01-25 Science Applications International Corporation Third party vpn certification
US7181542B2 (en) * 2000-04-12 2007-02-20 Corente, Inc. Method and system for managing and configuring virtual private networks
US7191195B2 (en) * 2001-11-28 2007-03-13 Oki Electric Industry Co., Ltd. Distributed file sharing system and a file access control method of efficiently searching for access rights
US7200642B2 (en) * 2001-04-29 2007-04-03 Geodigm Corporation Method and apparatus for electronic delivery of electronic model images
US20070081530A1 (en) * 2003-09-11 2007-04-12 Yuji Nomura Packet relay apparatus
US20070106795A1 (en) * 2005-11-08 2007-05-10 Gilfix Michael A Automatic orchestration of dynamic multiple party, multiple media communications
US20070192434A1 (en) * 2006-02-13 2007-08-16 Fujitsu Limited Network system, terminal, and gateway
US7299275B2 (en) * 2002-06-03 2007-11-20 Matsushita Electric Industrial Co., Ltd. Content delivery system for dynamically and optimally relocates contents to archive server, edge servers and terminal storage devices based on users' viewing tendency
US20080098088A1 (en) * 2005-01-13 2008-04-24 Hirokazu Tamano Communication System, Terminal Device And Communication Device
US7412489B2 (en) * 2003-08-21 2008-08-12 Ameriprise Financial, Inc. Method and system for electronic archival and retrieval of electronic communications
US20090177573A1 (en) * 2003-11-18 2009-07-09 Beadle Alastair J D System and method for managing relationships between brokers and traders
US7624175B1 (en) * 2003-11-03 2009-11-24 Sprint Communications Company L.P. Update messaging system
US7660809B2 (en) * 2005-01-31 2010-02-09 Microsoft Corporation Using a file server as a central shared database
US7701954B2 (en) * 1999-04-13 2010-04-20 Broadcom Corporation Gateway with voice
US7860978B2 (en) * 2004-01-22 2010-12-28 Toshiba America Research, Inc. Establishing a secure tunnel to access router

Family Cites Families (93)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000083067A (en) 1998-06-24 2000-03-21 Furukawa Electric Co Ltd:The Network system, inter-network connecting device having inquiry function and inter-network connecting device having holding function
JP2000099384A (en) 1998-09-17 2000-04-07 Nippon Telegr & Teleph Corp <Ntt> Method and system for high-security data link between various communication networks and storage medium storing data link program
JP2998839B1 (en) 1998-10-08 2000-01-17 株式会社エヌ・ティ・ティ・データ Data communication method, data relay device, and recording medium
JP3415456B2 (en) 1998-10-19 2003-06-09 日本電気株式会社 Network system, command use authority control method, and storage medium storing control program
GB2350269B (en) 1999-05-20 2003-10-22 Virtual Access Ireland Ltd An interface apparatus and method
JP4170523B2 (en) 1999-06-30 2008-10-22 富士通株式会社 Conversation support method and conversation support apparatus
JP2001092702A (en) 1999-09-20 2001-04-06 Fujitsu Ltd Information processing system, server device, client device and recording medium
JP2001155007A (en) 1999-12-01 2001-06-08 Ntt Comware Corp Synchronizing system for data base, data transmitting/ receiving system and electronic perusal system
JP2001184289A (en) 1999-12-27 2001-07-06 Js Corporation:Kk Chat system and information offering system on internet including the chat system
EP1139631A1 (en) 2000-03-31 2001-10-04 BRITISH TELECOMMUNICATIONS public limited company Method of initiating a data transfer from a server to a client
US7301952B2 (en) * 2000-04-06 2007-11-27 The Distribution Systems Research Institute Terminal-to-terminal communication connection control method using IP transfer network
JP2001306382A (en) 2000-04-24 2001-11-02 Hitachi Ltd Method for accessing shared file, device for executing the method and recording medium recording its processing program
JP2002007182A (en) 2000-06-20 2002-01-11 Nec Corp Shared file control system for external storage device
JP4092388B2 (en) 2000-11-10 2008-05-28 富士通株式会社 Service providing method using network and service providing system using the same
JP3489562B2 (en) 2000-12-26 2004-01-19 村田機械株式会社 Internet facsimile communication system and internet facsimile apparatus
JP4231985B2 (en) 2001-01-16 2009-03-04 村田機械株式会社 Relay server and communication system
JP4231984B2 (en) 2001-01-15 2009-03-04 村田機械株式会社 Relay server and communication system
JP2002247036A (en) 2001-02-21 2002-08-30 Nec Corp Network management system, its method and storage medium recording program for the method
JP2002269059A (en) 2001-03-08 2002-09-20 Ntt Comware Corp Client server system, repeating server, method for determining connection destination server of client terminal device
JP2002288415A (en) 2001-03-28 2002-10-04 Sanyo Electric Co Ltd Agent support device
JP3743506B2 (en) 2001-04-03 2006-02-08 村田機械株式会社 Relay server and relay system
JP3743507B2 (en) 2001-07-16 2006-02-08 村田機械株式会社 Relay server
JP2002342144A (en) 2001-05-21 2002-11-29 Toshiba Corp File sharing system, program and file transferring method
US6687733B2 (en) 2001-06-01 2004-02-03 Intergenix Method and system for automatically configuring a client-server network
JP2003006022A (en) 2001-06-18 2003-01-10 Fuji Electric Co Ltd Information distributing method in system information distribution system
JP2003006032A (en) 2001-06-19 2003-01-10 Fujitsu Ltd Distributed file sharing system
JP2003101565A (en) 2001-07-17 2003-04-04 Mitsubishi Materials Corp Mobile object management server, wireless mobile router, and accounting method
JP2003223521A (en) 2002-01-29 2003-08-08 Mitsubishi Electric Corp Facility management system and method
US6978627B2 (en) 2002-01-31 2005-12-27 Mitsubishi Denki Kabushiki Kaisha Air conditioner control system, central remote controller, and facility controller
JP4202378B2 (en) 2002-01-31 2008-12-24 三菱電機株式会社 Air conditioning system
JP2003258917A (en) 2002-02-28 2003-09-12 Spinnaker:Kk High-function gateway
JP3789842B2 (en) 2002-03-28 2006-06-28 エヌ・ティ・ティ・コムウェア株式会社 Content management method with security function and content management device with security function
US7702726B1 (en) 2002-04-10 2010-04-20 3Com Corporation System and methods for providing presence services in IP network
JP2004013479A (en) 2002-06-06 2004-01-15 Nec Corp Communication network and remote file access method
CN1178428C (en) 2002-09-12 2004-12-01 联想(北京)有限公司 Service renting and authorizing method for realizing resource sharing in household network
JP2004133600A (en) 2002-10-09 2004-04-30 Matsushita Electric Ind Co Ltd Electronic data sharing system and method using email and recording medium for achieving this method
JP2004139291A (en) 2002-10-17 2004-05-13 Hitachi Ltd Data communication repeater
JP3990272B2 (en) 2002-12-20 2007-10-10 富士通株式会社 Mailing list management system and e-mail transmission / reception device
JP2004213533A (en) 2003-01-08 2004-07-29 Seiko Epson Corp Screen reception device, screen delivery device, screen information transmission/reception system, screen reception method, screen delivery method and program therefor
JP2004215135A (en) 2003-01-08 2004-07-29 Fuji Xerox Co Ltd Image processor
JP4052126B2 (en) 2003-01-22 2008-02-27 日本電気株式会社 Leased line service providing system and leased line service method used therefor
JP4349365B2 (en) * 2003-02-19 2009-10-21 日本ビクター株式会社 Control information transmission method, relay server, and controlled device
JP2004310371A (en) 2003-04-04 2004-11-04 Nippon Telegr & Teleph Corp <Ntt> System, method, server for sharing file and client terminal for file sharing service, file sharing program and recording medium with program recorded
JP4165283B2 (en) 2003-04-22 2008-10-15 村田機械株式会社 Facsimile machine
JP2004341849A (en) 2003-05-15 2004-12-02 Cybozu Inc Information sharing system, information sharing support server and program
JP2004362166A (en) 2003-06-03 2004-12-24 J'z Factory:Kk Data management system and method, server, computer program, and recording medium recorded with computer program
JP2005027040A (en) 2003-07-02 2005-01-27 Ricoh Co Ltd Monitoring method, program and centralized monitoring program
JP2005038104A (en) 2003-07-17 2005-02-10 Toshiba Corp Information processor
JP3941763B2 (en) 2003-09-09 2007-07-04 日本電信電話株式会社 Congestion control system for client-server service
US7467190B2 (en) 2003-10-06 2008-12-16 Hitachi, Ltd. Method and apparatus for alert distribution and archive sharing
US7567987B2 (en) 2003-10-24 2009-07-28 Microsoft Corporation File sharing in P2P group shared spaces
US20050114436A1 (en) 2003-11-12 2005-05-26 Sandeep Betarbet Terminating file handling system
JP4310174B2 (en) 2003-11-26 2009-08-05 株式会社日立製作所 Large display system
JP2005167608A (en) 2003-12-02 2005-06-23 Canon Inc System and method for ciphered communication computer program, and computer readable recording medium
JP4576115B2 (en) 2003-12-18 2010-11-04 株式会社日立製作所 VoIP gateway device and method for controlling call arrival and departure in VoIP gateway device
JP2005210352A (en) 2004-01-22 2005-08-04 Nec Engineering Ltd Ip address converter and converting method
US8065418B1 (en) * 2004-02-02 2011-11-22 Apple Inc. NAT traversal for media conferencing
GB2411541B (en) 2004-02-26 2006-09-13 Siemens Ag A sip server
EP1730911A1 (en) 2004-03-30 2006-12-13 Matsushita Electric Industries Co., Ltd. Content relay server, content relay system, content relay method, and program using the same
JP3940135B2 (en) 2004-05-13 2007-07-04 日本電信電話株式会社 RESOURCE MANAGEMENT SYSTEM AND METHOD, PROGRAM, AND RECORDING MEDIUM CONTAINING PROGRAM
JP2006013757A (en) 2004-06-24 2006-01-12 Matsushita Electric Ind Co Ltd Home network remote management system
JP4366270B2 (en) 2004-07-30 2009-11-18 キヤノン株式会社 Network connection setting device and network connection setting method
JP2006067045A (en) 2004-08-25 2006-03-09 Canon Inc Communications device, its control method and program
EP1789888A4 (en) 2004-09-03 2009-09-23 Open Text Corp Systems and methods for collaboration
GB2420257B (en) 2004-11-16 2007-12-12 Vodafone Plc Facilitating distribution of information in a network
JP2006172192A (en) 2004-12-16 2006-06-29 Nec Corp System and method for inter-enterprise data exchange, and its program
WO2006090465A1 (en) 2005-02-24 2006-08-31 Fujitsu Limited Connection support device and gateway device
JP2006268138A (en) 2005-03-22 2006-10-05 Fuji Xerox Co Ltd Image forming apparatus, information processing method, information processing program and peer-to-peer system
JP4379379B2 (en) 2005-04-27 2009-12-09 株式会社日立製作所 Network system
EP1891782B1 (en) 2005-05-26 2018-08-22 XConnect Global Networks Ltd. Detection of spit in voip calls
JP2007074035A (en) 2005-09-02 2007-03-22 Canon Inc Communication apparatus and information processing method
JP2007086910A (en) 2005-09-20 2007-04-05 Nec Corp Information sharing system, information sharing method and information sharing program
JP2007104440A (en) 2005-10-05 2007-04-19 Dit:Kk Packet transmission system, its method, and tunneling device
JP2007265135A (en) 2006-03-29 2007-10-11 Murata Mach Ltd Data management server and communication system
JP2007310508A (en) 2006-05-16 2007-11-29 Nippon Telegraph & Telephone East Corp Thin client system and program for thin client terminal
JP5101852B2 (en) 2006-10-05 2012-12-19 日本電信電話株式会社 Connection control system, connection control method, and data relay device
JP2008098888A (en) 2006-10-11 2008-04-24 Murata Mach Ltd Relay server
EP1942634B1 (en) 2006-11-24 2012-08-29 Murata Machinery, Ltd. Relay server, relay communication system, and communication device
JP4274231B2 (en) 2006-11-24 2009-06-03 村田機械株式会社 Relay server and relay communication system
JP5125087B2 (en) 2006-12-13 2013-01-23 村田機械株式会社 Relay server
JP4957225B2 (en) 2006-12-11 2012-06-20 村田機械株式会社 Relay server and relay communication system
JP4661774B2 (en) 2006-12-12 2011-03-30 村田機械株式会社 Relay server
JP4333736B2 (en) 2006-12-19 2009-09-16 村田機械株式会社 Relay server and client terminal
JP4453698B2 (en) 2006-12-19 2010-04-21 村田機械株式会社 Relay server
WO2008085203A2 (en) 2006-12-29 2008-07-17 Prodea Systems, Inc. Presence status notification from digital endpoint devices through a multi-services gateway device at the user premises
EP1990974A3 (en) 2007-05-02 2010-03-24 Murata Machinery, Ltd. Relay server and relay communication system
JP4656536B2 (en) 2007-05-09 2011-03-23 村田機械株式会社 Relay server and relay communication system
JP4750761B2 (en) 2007-07-23 2011-08-17 日本電信電話株式会社 Connection control system, connection control method, connection control program, and relay device
JP5257968B2 (en) 2007-07-24 2013-08-07 日本電信電話株式会社 Information sharing method, information sharing network system, information sharing server and program
JP4753165B2 (en) 2007-12-28 2011-08-24 村田機械株式会社 Relay server and relay communication system
JP4784598B2 (en) 2007-12-28 2011-10-05 村田機械株式会社 Relay server and relay communication system
JP2009252159A (en) 2008-04-10 2009-10-29 Murata Mach Ltd File sharing system
JP2009265919A (en) 2008-04-24 2009-11-12 Murata Mach Ltd File sharing system and relay server

Patent Citations (99)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5224205A (en) * 1990-05-21 1993-06-29 International Business Machines Corp. Method of combining architecturally dissimilar computing networks into a single logical network
US5535375A (en) * 1992-04-20 1996-07-09 International Business Machines Corporation File manager for files shared by heterogeneous clients
US6636513B1 (en) * 1995-09-06 2003-10-21 Fujitsu Limited Switching system
US6226692B1 (en) * 1995-12-15 2001-05-01 Object Dynamics Corporation Method and system for constructing software components and systems as assemblies of independent parts
US5848134A (en) * 1996-01-31 1998-12-08 Sony Corporation Method and apparatus for real-time information processing in a multi-media system
US6237023B1 (en) * 1996-06-14 2001-05-22 Canon Kabushiki Kaisha System for controlling the authority of a terminal capable of simultaneously operating a plurality of client softwares which transmit service requests
US6111883A (en) * 1996-07-12 2000-08-29 Hitachi, Ltd. Repeater and network system utilizing the same
US6754212B1 (en) * 1996-07-12 2004-06-22 Hitachi, Ltd. Repeater and network system utililzing the same
US6222536B1 (en) * 1996-12-30 2001-04-24 Korea Telecom Method and apparatus for providing a number of subscribers with on-line banking service employing a plurality of bank systems
US6336141B1 (en) * 1997-01-08 2002-01-01 Hitachi, Ltd. Method of collectively managing dispersive log, network system and relay computer for use in the same
US5884312A (en) * 1997-02-28 1999-03-16 Electronic Data Systems Corporation System and method for securely accessing information from disparate data sources through a network
US6650631B1 (en) * 1997-03-11 2003-11-18 Verizon Services Corp. Public IP transport network
US6061796A (en) * 1997-08-26 2000-05-09 V-One Corporation Multi-access virtual private network
US6546488B2 (en) * 1997-09-22 2003-04-08 Hughes Electronics Corporation Broadcast delivery of information to a personal computer for local storage and access
US20010044819A1 (en) * 1997-11-07 2001-11-22 International Business Machines Corporation Relay server for unsigned applets
US6324574B1 (en) * 1997-11-07 2001-11-27 International Business Machines Corporation Relay server for unsigned applets
US6765686B2 (en) * 1997-11-14 2004-07-20 Canon Kabushiki Kaisha Image processing apparatus, method of controlling same, and image processing system
US6215877B1 (en) * 1998-03-20 2001-04-10 Fujitsu Limited Key management server, chat system terminal unit, chat system and recording medium
US6178427B1 (en) * 1998-05-07 2001-01-23 Platinum Technology Ip, Inc. Method of mirroring log datasets using both log file data and live log data including gaps between the two data logs
US6594246B1 (en) * 1998-07-10 2003-07-15 Malibu Networks, Inc. IP-flow identification in a wireless point to multi-point transmission system
US6145084A (en) * 1998-10-08 2000-11-07 Net I Trust Adaptive communication system enabling dissimilar devices to exchange information over a network
US6538773B1 (en) * 1999-03-26 2003-03-25 International Business Machines Corporation Method and apparatus for rendering grayscales at a facsimile presentation device using a calibrated transform
US7701954B2 (en) * 1999-04-13 2010-04-20 Broadcom Corporation Gateway with voice
US6564261B1 (en) * 1999-05-10 2003-05-13 Telefonaktiebolaget Lm Ericsson (Publ) Distributed system to intelligently establish sessions between anonymous users over various networks
US7120927B1 (en) * 1999-06-09 2006-10-10 Siemens Communications, Inc. System and method for e-mail alias registration
US6889256B1 (en) * 1999-06-11 2005-05-03 Microsoft Corporation System and method for converting and reconverting between file system requests and access requests of a remote transfer protocol
US6898641B1 (en) * 2000-04-10 2005-05-24 Fujitsu Limited Network routing system and routing apparatus
US20020056003A1 (en) * 2000-04-11 2002-05-09 Dinkar Goswami System and method for real-time multi-directional file-based data streaming editor
US20020023143A1 (en) * 2000-04-11 2002-02-21 Stephenson Mark M. System and method for projecting content beyond firewalls
US20020029276A1 (en) * 2000-04-12 2002-03-07 Samuel Bendinelli Methods and systems for an extranet
US7181542B2 (en) * 2000-04-12 2007-02-20 Corente, Inc. Method and system for managing and configuring virtual private networks
US7174378B2 (en) * 2000-05-29 2007-02-06 Nitgen Technologies, Inc. Co-location service system equipped with global load balancing (GLB) function among dispersed IDCS
US20010047414A1 (en) * 2000-05-29 2001-11-29 Yoon Ki J. Dedicated private network service method having backup and loads-balancing functions
US6766373B1 (en) * 2000-05-31 2004-07-20 International Business Machines Corporation Dynamic, seamless switching of a network session from one connection route to another
US6988199B2 (en) * 2000-07-07 2006-01-17 Message Secure Secure and reliable document delivery
US20020143960A1 (en) * 2000-08-02 2002-10-03 Erez Goren Virtual network generation system and method
US20020032616A1 (en) * 2000-08-22 2002-03-14 Kazunori Suzuki Relay server, relaying method and payment system
US6757365B1 (en) * 2000-10-16 2004-06-29 Tellme Networks, Inc. Instant messaging via telephone interfaces
US7000248B2 (en) * 2000-11-01 2006-02-14 Nec Corporation Virtual network and virtual network connection system
US20020073182A1 (en) * 2000-12-08 2002-06-13 Zakurdaev Maxim V. Method and apparatus for a smart DHCP relay
US20020095506A1 (en) * 2001-01-15 2002-07-18 Murata Kikai Kabushiki Kaisha Relay server, communication system and facsimile system
US7206088B2 (en) * 2001-01-15 2007-04-17 Murata Kikai Kabushiki Kaisha Relay server, communication system and facsimile system
US20020118398A1 (en) * 2001-01-15 2002-08-29 Murata Kikai Kabushiki Kaisha Relay server, communication system and facsimile system
US20070022477A1 (en) * 2001-01-18 2007-01-25 Science Applications International Corporation Third party vpn certification
US7574523B2 (en) * 2001-01-22 2009-08-11 Sun Microsystems, Inc. Relay peers for extending peer availability in a peer-to-peer networking environment
US20020143855A1 (en) * 2001-01-22 2002-10-03 Traversat Bernard A. Relay peers for extending peer availability in a peer-to-peer networking environment
US20020152299A1 (en) * 2001-01-22 2002-10-17 Traversat Bernard A. Reliable peer-to-peer connections
US6950879B2 (en) * 2001-01-24 2005-09-27 Interland, Inc. Using virtual network address information during communications
US7110393B1 (en) * 2001-02-28 2006-09-19 3Com Corporation System and method for providing user mobility handling in a network telephony system
US20020143922A1 (en) * 2001-04-03 2002-10-03 Murata Kikai Kabushiki Kaisha Relay server and relay system
US20020143956A1 (en) * 2001-04-03 2002-10-03 Murata Kikai Kabushiki Kaisha Relay server
US20020143957A1 (en) * 2001-04-03 2002-10-03 Murata Kikai Kabushiki Kaisha Relay server, network device, communication system, and communication method
US20020146002A1 (en) * 2001-04-10 2002-10-10 Takayuki Sato Network administration apparatus, network administrating program, network administrating method and computer network system
US20020156875A1 (en) * 2001-04-24 2002-10-24 Kuldipsingh Pabla Peer group name server
US7200642B2 (en) * 2001-04-29 2007-04-03 Geodigm Corporation Method and apparatus for electronic delivery of electronic model images
US20030021232A1 (en) * 2001-07-27 2003-01-30 Jerome Duplaix Scalable router
US20040255048A1 (en) * 2001-08-01 2004-12-16 Etai Lev Ran Virtual file-sharing network
US7139811B2 (en) * 2001-08-01 2006-11-21 Actona Technologies Ltd. Double-proxy remote data access system
US20030055741A1 (en) * 2001-08-21 2003-03-20 Kabushiki Kaisha Toshiba Server for exchanging design information, method for exchanging design information, program for exchanging design information, buying method of special design product and selling method of special design product
US20030097456A1 (en) * 2001-11-08 2003-05-22 Huh Mi Young Method for synchronizing registration information within intra-domain
US7191195B2 (en) * 2001-11-28 2007-03-13 Oki Electric Industry Co., Ltd. Distributed file sharing system and a file access control method of efficiently searching for access rights
US7257638B2 (en) * 2001-12-20 2007-08-14 Microsoft Corporation Distributing network applications
US20060020695A1 (en) * 2001-12-20 2006-01-26 Microsoft Corporation Scaling and delivering distributed applications
US20050256909A1 (en) * 2002-04-03 2005-11-17 Aboulhosn Amir L Peer-to-peer file sharing
US20040068524A1 (en) * 2002-04-03 2004-04-08 Aboulhosn Amir L. Peer-to-peer file sharing
US6938042B2 (en) * 2002-04-03 2005-08-30 Laplink Software Inc. Peer-to-peer file sharing
US7299275B2 (en) * 2002-06-03 2007-11-20 Matsushita Electric Industrial Co., Ltd. Content delivery system for dynamically and optimally relocates contents to archive server, edge servers and terminal storage devices based on users' viewing tendency
US7152111B2 (en) * 2002-08-15 2006-12-19 Digi International Inc. Method and apparatus for a client connection manager
US20040073610A1 (en) * 2002-09-30 2004-04-15 Katsuhiko Terada Contents reproducing system
US20040083385A1 (en) * 2002-10-25 2004-04-29 Suhail Ahmed Dynamic network security apparatus and methods for network processors
US20060259553A1 (en) * 2003-02-03 2006-11-16 Jun Kawakita Synchronization program
US7774495B2 (en) * 2003-02-13 2010-08-10 Oracle America, Inc, Infrastructure for accessing a peer-to-peer network environment
US20040162871A1 (en) * 2003-02-13 2004-08-19 Pabla Kuldipsingh A. Infrastructure for accessing a peer-to-peer network environment
US20040172395A1 (en) * 2003-02-28 2004-09-02 Microsoft Corporation Method to delay locking of server files on edit
US20040243703A1 (en) * 2003-04-14 2004-12-02 Nbt Technology, Inc. Cooperative proxy auto-discovery and connection interception
US20040267939A1 (en) * 2003-06-30 2004-12-30 Hitachi, Ltd. Session control apparatus, software applied to session control apparatus, communication control method, and network system
US7412489B2 (en) * 2003-08-21 2008-08-12 Ameriprise Financial, Inc. Method and system for electronic archival and retrieval of electronic communications
US20070081530A1 (en) * 2003-09-11 2007-04-12 Yuji Nomura Packet relay apparatus
US7624175B1 (en) * 2003-11-03 2009-11-24 Sprint Communications Company L.P. Update messaging system
US20090177573A1 (en) * 2003-11-18 2009-07-09 Beadle Alastair J D System and method for managing relationships between brokers and traders
US20050144289A1 (en) * 2003-12-03 2005-06-30 Hitachi, Ltd. Connection control system, connection control equipment and connection management equipment
US7860978B2 (en) * 2004-01-22 2010-12-28 Toshiba America Research, Inc. Establishing a secure tunnel to access router
US20050216523A1 (en) * 2004-03-26 2005-09-29 Akihiko Sakaguchi File management method in a distributed storage system
US20050281251A1 (en) * 2004-06-21 2005-12-22 Hitachi, Ltd. Session control system for hierarchical relaying processes
US7813299B2 (en) * 2004-06-21 2010-10-12 Hitachi, Ltd. Session control system for hierarchical relaying processes
US20050287998A1 (en) * 2004-06-29 2005-12-29 Nec Corporation Conference assisting system and method
US20060083171A1 (en) * 2004-07-13 2006-04-20 Aruze Corporation Media communication apparatus and media communication program product
US20060101064A1 (en) * 2004-11-08 2006-05-11 Sharpcast, Inc. Method and apparatus for a file sharing and synchronization system
US20060117076A1 (en) * 2004-11-29 2006-06-01 Spencer William A Method for replication tracing
US20060149771A1 (en) * 2005-01-05 2006-07-06 Hitachi, Ltd. Information processing system and communication retry method
US20080098088A1 (en) * 2005-01-13 2008-04-24 Hirokazu Tamano Communication System, Terminal Device And Communication Device
US7660809B2 (en) * 2005-01-31 2010-02-09 Microsoft Corporation Using a file server as a central shared database
US20060187902A1 (en) * 2005-02-24 2006-08-24 Oliver Birch Method and apparatus for session initiation protocol application design, development, execution and integration
US20060206616A1 (en) * 2005-03-14 2006-09-14 Gridiron Software, Inc. Decentralized secure network login
US20060256771A1 (en) * 2005-05-12 2006-11-16 Yahoo! Inc. Proxy server for relaying VOIP messages
US20060282540A1 (en) * 2005-06-08 2006-12-14 Murata Kikai Kabushiki Kaisha File server device, communication management server device, and network system including the file server device and the communication management server device
US20070019545A1 (en) * 2005-07-20 2007-01-25 Mci, Inc. Method and system for securing real-time media streams in support of interdomain traversal
US20070106795A1 (en) * 2005-11-08 2007-05-10 Gilfix Michael A Automatic orchestration of dynamic multiple party, multiple media communications
US20070192434A1 (en) * 2006-02-13 2007-08-16 Fujitsu Limited Network system, terminal, and gateway

Cited By (46)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8472454B2 (en) 2006-09-12 2013-06-25 Murata Machinery, Ltd. Relay-server arranged to carry out communications between communication terminals on different LANS
US20080063001A1 (en) * 2006-09-12 2008-03-13 Murata Machinery, Ltd. Relay-server
US20080091768A1 (en) * 2006-10-11 2008-04-17 Murata Machinery, Ltd File transfer server
US20080089349A1 (en) * 2006-10-11 2008-04-17 Murata Machinery, Ltd File server device
US8316134B2 (en) 2006-10-11 2012-11-20 Murata Machinery, Ltd. File server device arranged in a local area network and being communicable with an external server arranged in a wide area network
US8443088B2 (en) 2006-10-11 2013-05-14 Murata Machinery, Ltd. File transfer server
US20080288591A1 (en) * 2006-11-24 2008-11-20 Murata Machinery, Ltd. Relay server, relay communication system, and communication device
US8005961B2 (en) 2006-11-24 2011-08-23 Murata Machinery, Ltd. Relay server, relay communication system, and communication device
US20080137672A1 (en) * 2006-12-11 2008-06-12 Murata Machinery, Ltd. Relay server and relay communication system
US8010647B2 (en) 2006-12-11 2011-08-30 Murata Machinery, Ltd. Relay server and relay communication system arranged to share resources between networks
US20080147825A1 (en) * 2006-12-19 2008-06-19 Murata Machinery, Ltd. Relay server and client terminal
US8010598B2 (en) 2006-12-19 2011-08-30 Murata Machinery, Ltd. Relay server and client terminal
US8005893B2 (en) 2007-05-02 2011-08-23 Murata Machinery, Ltd. Relay server and relay communication system
US8606941B2 (en) 2007-05-02 2013-12-10 Murata Machinery, Ltd. Relay server and relay communication system
US20080275945A1 (en) * 2007-05-02 2008-11-06 Murata Machinery, Ltd. Relay server and relay communication system
US20080275953A1 (en) * 2007-05-02 2008-11-06 Murata Machinery, Ltd. Relay server and relay communication system
US8307100B2 (en) 2007-05-09 2012-11-06 Murata Machinery, Ltd. Relay server and relay communication system
US20080281981A1 (en) * 2007-05-09 2008-11-13 Murata Machinery, Ltd. Relay server and relay communication system
US8949419B2 (en) 2007-12-25 2015-02-03 Murata Machinery, Ltd. Synchronizing sharing servers
US20090164636A1 (en) * 2007-12-25 2009-06-25 Murata Machinery, Ltd. Relay server and relay communication system
US20090164637A1 (en) * 2007-12-25 2009-06-25 Murata Machinery, Ltd. Relay server and relay communication system
US8010675B2 (en) 2007-12-25 2011-08-30 Murata Machinery, Ltd. Relay server and relay communication system
US20090172166A1 (en) * 2007-12-27 2009-07-02 Murata Machinery, Ltd. Relay server and relay communication system
US8321575B2 (en) 2007-12-27 2012-11-27 Murata Machinery, Ltd. Relay server and relay communication system
US8069246B2 (en) 2007-12-28 2011-11-29 Murata Machinery, Ltd. Relay server and relay communication system including a relay group information registration unit, a shared resource information registration unit, and a control unit
US20090172075A1 (en) * 2007-12-28 2009-07-02 Murata Machinery, Ltd. Relay server and relay communication system
US20110161525A1 (en) * 2008-09-01 2011-06-30 Murata Machinery, Ltd. Relay server and relay communication system
US8356116B2 (en) 2008-09-01 2013-01-15 Murata Machinery, Ltd. Relay server and relay communication system
US20110179167A1 (en) * 2008-09-05 2011-07-21 Murata Machinery, Ltd. Relay server, relay communication system, and communication apparatus
US8296391B2 (en) 2008-09-05 2012-10-23 Murata Machinery, Ltd. Relay server, relay communication system, and communication apparatus
US9246879B2 (en) * 2008-10-03 2016-01-26 At&T Intellectual Property, I., L.P. Methods and apparatus to form secure cross-virtual private network communication sessions
US20150040207A1 (en) * 2008-10-03 2015-02-05 At&T Intellectual Property, I, L.P. Methods and apparatus to form secure cross-virtual private network communication sessions
US20130177013A1 (en) * 2008-10-03 2013-07-11 At&T Intellectual Property I, Lp Methods and apparatus to form secure cross-virtual private network communication sessions
US20100085957A1 (en) * 2008-10-03 2010-04-08 Elias Mark A Methods and Apparatus to Form Secure Cross-Virtual Private Network Communications Sessions
US8391276B2 (en) * 2008-10-03 2013-03-05 At&T Intellectual Property I, Lp Methods and apparatus to form secure cross-virtual private network communications sessions
US8879543B2 (en) * 2008-10-03 2014-11-04 At&T Intellectual Property I, L.P. Methods and apparatus to form secure cross-virtual private network communication sessions
US20100235497A1 (en) * 2009-03-11 2010-09-16 Canon Kabushiki Kaisha Information processing apparatus and communication processing method thereof
US9307068B2 (en) 2009-03-11 2016-04-05 Canon Kabushiki Kaisha Information processing apparatus and communication processing method thereof
US8798082B2 (en) 2009-05-15 2014-08-05 Murata Machinery, Ltd. Relay communication system and first relay server
US9137313B2 (en) * 2010-12-27 2015-09-15 Samsung Sds Co., Ltd. Data transmission system and method using relay server
US20120166593A1 (en) * 2010-12-27 2012-06-28 Samsung Sds Co., Ltd. Data transmission system and method using relay server
US20130136130A1 (en) * 2011-11-30 2013-05-30 Murata Machinery, Ltd. Relay server and relay communication system
US20150312363A1 (en) * 2014-04-25 2015-10-29 Pravala Networks Inc. Using proxy devices as dynamic data relays
US9854051B2 (en) * 2014-04-25 2017-12-26 Wilmerding Communications Llc Using proxy devices as dynamic data relays
US20170012828A1 (en) * 2015-07-08 2017-01-12 Kabushiki Kaisha Toshiba Relay apparatus
US10397029B2 (en) * 2015-07-08 2019-08-27 Toshiba Memory Corporation Relay apparatus

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