Relay device and communication system

• US 20070233844A1
• Filed: 03/20/2007
• Published: 10/04/2007
• Est. Priority Date: 03/29/2006
• Status: Abandoned Application

• Current Assignee: Murata Machinery Limited (Muratec)
• Original Assignee: Murata Machinery Limited (Muratec)
• Inventors: Tanimoto, Yoshifumi
• Application Number:
  US11/723,466
• Publication Number:
  US 20070233844A1
• Time in Patent Office: Days
• US Class Current: 709/223
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 67/56 Provisioning of proxy services store-and-forward switching systems in data switching networks H04L12/54
• CPC Class Codes: H04L 67/568 Storing data temporarily at an intermediate stage, e.g. caching

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.

Claims

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.