Multi-Interface Communication Device, Terminal, And Path Switching Method

• US 20080008165A1
• Filed: 11/04/2005
• Published: 01/10/2008
• Est. Priority Date: 11/04/2004
• Status: Active Grant

• Current Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Funabiki, Makoto, Ikeda, Shinkichi, Kumazawa, Masayuki
• Granted Patent: US 7,894,383 B2
• Time in Patent Office: Days
• US Class Current: 370/360
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/28 using route fault recovery
• CPC Class Codes: H04L 45/60 Router architectures

Abstract

A router, if judging that a routing function is impossible to execute, sends out a connection instruction message including the address of a terminal on a local network terminating the relaying flow, to another router to solicit switching. The router having received the connection instruction message starts a process for connecting with an external network while executing a process for link connection with a terminal, and then sends out a connection completion notice message when the connection with both the external network and the terminal is established. This process enables the router to switch a path rapidly.

Claims

1. A path switching method for switching a plurality of multi-interface communication devices having a plurality of communication interfaces, on one local wireless network, comprising:

a step in which a first multi-interface communication device sends out a connection instruction to a second multi-interface communication device;

a step in which the second multi-interface communication device, when receiving the connection instruction, starts a process for connecting to an external network;

a step in which the second multi-interface communication device, when completing the connection, sends out a connection completion notice for notifying of completion of the connection, to the first multi-interface communication device, and sends out a self information notice for notifying of self network information, to the local wireless network;

a step in which the first multi-interface communication device, when receiving the connection completion notice, notifies the local wireless network of a path switching instruction; and

a step in which a terminal that has received the self information notice and the path switching instruction changes a multi-interface communication device to be used for relaying from the first multi-interface communication device to the second one.

2. The path switching method of claim 1, wherein the first multi-interface communication device sends out the connection instruction in one of cases in which:

a rate of packet loss in communication with the external network is higher than a given value;

intensity of received radio waves is lower than a given value;

a self shutdown is started; and

the first multi-interface communication device receives a request for switching to an other multi-interface communication device.

3. The path switching method of claim 1, wherein the connection process by the second multi-interface communication device is started when the possibility of connecting with the external network exists, and the second multi-interface communication device has a step of sending out a connection instruction reply for notifying the first multi-interface communication device that connection with an external network has been started.

4. The path switching method of claim 3, wherein the first multi-interface communication device sends out communication performance requirements based on a property of a communication flow being relayed, included in the connection instruction, and the second multi-interface communication device, if performance of communication with the external network as a connection target further satisfies the communication performance requirements, starts the connection process.

5. The path switching method of claim 4,

wherein the second multi-interface communication device does not start the process for connecting with the external network, if the possibility of connecting with the external network does not exist, or if the communication performance requirements are not satisfied although the possibility of connecting with the external network exists, and

wherein the second multi-interface communication device further has a step of sending out a connection instruction reply for notifying that connection with the external network has not been executed.

6. The path switching method of claim 5, further comprising a step in which the first multi-interface communication device, if receiving a connection instruction reply for notifying that connection with the external network has not been executed, from the second multi-interface communication device, sends out a path switching instruction to a third multi-interface communication device.

7. The path switching method of claim 1, wherein the second multi-interface communication device, after or instead of sending out the connection completion notice, notifies the local wireless network of the path switching instruction instead of the step in which the first multi-interface communication device notifies of the path switching instruction.

8. The path switching method of claim 1, further comprising:

a step in which the first multi-interface communication device sends out a terminal identifier for specifying a terminal while relaying on the local wireless network, along with the connection instruction, to the second multi-interface communication device; and

a step in which the second multi-interface communication device starts a process for connecting with a terminal specified by the terminal identifier.

9. The path switching method of claim 8, wherein the second multi-interface communication device, when completing connection with both the external network and the terminal, sends out the self information notice and the connection completion notice.

10. The path switching method of claim 8, wherein a terminal specified by the terminal identifier is specified out of those registered in a neighbor cache or ARP cache of the first multi-interface communication device.

11. The path switching method of claim 1, further comprising:

a step in which the second multi-interface communication device, when a state of the possibility of connection with the external network changes, sends out a connection possibility notice for notifying the first multi-interface communication device of possibility of connection;

a step in which the first multi-interface communication device, when receiving a connection-possible notice, stores information of connection possible of the second multi-interface communication device, included in the connection possibility notice; and

when receiving information of connection impossible, deletes storage of information of connection possible of the second multi-interface communication device; and

a step in which the first multi-interface communication device, when sending out the connection instruction, determines a sending-out destination according to information on connection possibility of the second multi-interface communication device.

12. The path switching method of claim 11,

wherein the connection possibility notice includes an identifier of a multi-interface communication device and performance of communication with an external network;

and

wherein the first multi-interface communication device determines a connectable multi-interface communication device having communication performance suitable for a property of a relay flow, in communication with the external network, as a sending-out destination of the connection instruction.

30. The path switching method of claim 2, further comprising:

a step in which the first multi-interface communication device sends out a terminal identifier for specifying a terminal while relaying on the local wireless network, along with the connection instruction, to the second multi-interface communication device; and

a step in which the second multi-interface communication device starts a process for connecting with a terminal specified by the terminal identifier.

31. The path switching method of claim 3, further comprising:

a step in which the first multi-interface communication device sends out a terminal identifier for specifying a terminal while relaying on the local wireless network, along with the connection instruction, to the second multi-interface communication device; and

a step in which the second multi-interface communication device starts a process for connecting with a terminal specified by the terminal identifier.

32. The path switching method of claim 4, further comprising:

a step in which the first multi-interface communication device sends out a terminal identifier for specifying a terminal while relaying on the local wireless network, along with the connection instruction, to the second multi-interface communication device; and

a step in which the second multi-interface communication device starts a process for connecting with a terminal specified by the terminal identifier.

33. The path switching method of claim 5, further comprising:

a step in which the first multi-interface communication device sends out a terminal identifier for specifying a terminal while relaying on the local wireless network, along with the connection instruction, to the second multi-interface communication device; and

a step in which the second multi-interface communication device starts a process for connecting with a terminal specified by the terminal identifier.

34. The path switching method of claim 6, further comprising:

a step in which the first multi-interface communication device sends out a terminal identifier for specifying a terminal while relaying on the local wireless network, along with the connection instruction, to the second multi-interface communication device; and

a step in which the second multi-interface communication device starts a process for connecting with a terminal specified by the terminal identifier.

35. The path switching method of claim 7, further comprising:

a step in which the first multi-interface communication device sends out a terminal identifier for specifying a terminal while relaying on the local wireless network, along with the connection instruction, to the second multi-interface communication device; and

a step in which the second multi-interface communication device starts a process for connecting with a terminal specified by the terminal identifier.

13. A multi-interface communication device having a plurality of communication interfaces, comprising:

a connection management unit that detects at least one of a deteriorated state of connection with an external network, a self shutdown, reception of a switching request that requests connection with an external network to be switched to an other multi-interface communication device;

a path management unit that notifies an other multi-interface communication device on a local network on which the multi-interface communication device is connecting, of an instruction for connecting with the external network and an identifier for specifying a terminal registered in a neighbor cache or ARP cache, responding to the detection notice;

a receiving unit that receives a notice of completion of connection with the external network, from a multi-interface communication device as a notice destination of the connection instruction; and

a path switching instructing unit that notifies the local network of a path switching instruction for instructing switching a multi-interface communication device used for relaying, responding to a connection completion notice from the receiving unit.

14. The multi-interface communication device of claim 13, wherein the identifier notified by the path management unit is an identifier of a terminal that is an end of a flow relayed in a given time.

15. The multi-interface communication device of claim 13, wherein the path management unit sends out a request parameter showing communication quality and communication performance based on a property of a communication flow being relayed, along with the connection instruction.

16. The multi-interface communication device of claim 13,

wherein the receiving unit receives a connection instruction reply for notifying of disconnection with the external network, from a multi-interface communication device as a notice destination of the connection instruction;

and

wherein the path management unit, responding to a notice of the connection instruction reply from the receiving unit, sends out a connection instruction to a multi-interface communication device as a different destination.

17. The path switching device of claim 16,

wherein the receiving unit receives a notice of possibility of connection with an external network, from an other multi-interface communication device on the local network;

and

wherein the path switching unit, when receiving a notice of connection possible from the receiving unit, stores an identifier specifying a multi-interface communication device as a transmission origin of the connection possibility notice, and when receiving a notice of connection impossible, deletes storage of an identifier specifying the transmission-origin multi-interface communication device and determines a sending-out destination of the connection instruction out of the stored identifiers.

18. The multi-interface communication device of claim 17,

wherein the connection possibility notice includes possibility of connection with an external network, an identifier specifying a self, and capacity of communication with the external network;

and

wherein the path switching unit determines a multi-interface communication device with communication capacity suitable for a property of a relay flow, according to the connection possibility notice, as a sending-out destination of a connection instruction.

19. The multi-interface communication device of claim 17, wherein the path management unit sends out an instant notice solicitation for soliciting instantly sending out the connection possibility notice, the connection instruction reply, and the connection completion notice.

20. The multi-interface communication device of claim 13, wherein, if the receiving unit receives a path switching instruction from a multi-interface communication device as a notice destination of the connection instruction before receiving the connection completion notice, the path switching instructing unit stops sending out the path switching instruction.

36. The multi-interface communication device of claim 14, wherein, if the receiving unit receives a path switching instruction from a multi-interface communication device as a notice destination of the connection instruction before receiving the connection completion notice, the path switching instructing unit stops sending out the path switching instruction.

37. The multi-interface communication device of claim 15, wherein, if the receiving unit receives a path switching instruction from a multi-interface communication device as a notice destination of the connection instruction before receiving the connection completion notice, the path switching instructing unit stops sending out the path switching instruction.

38. The multi-interface communication device of claim 16, wherein, if the receiving unit receives a path switching instruction from a multi-interface communication device as a notice destination of the connection instruction before receiving the connection completion notice, the path switching instructing unit stops sending out the path switching instruction.

39. The multi-interface communication device of claim 17, wherein, if the receiving unit receives a path switching instruction from a multi-interface communication device as a notice destination of the connection instruction before receiving the connection completion notice, the path switching instructing unit stops sending out the path switching instruction.

40. The multi-interface communication device of claim 18, wherein, if the receiving unit receives a path switching instruction from a multi-interface communication device as a notice destination of the connection instruction before receiving the connection completion notice, the path switching instructing unit stops sending out the path switching instruction.

41. The multi-interface communication device of claim 19, wherein, if the receiving unit receives a path switching instruction from a multi-interface communication device as a notice destination of the connection instruction before receiving the connection completion notice, the path switching instructing unit stops sending out the path switching instruction.

21. A multi-interface communication device having a plurality of communication interfaces, comprising:

an instruction receiving unit that receives an instruction of connection with an external network and a notice of an identifier specifying a terminal on a local network;

an external link processing unit that executes a process for connecting to the external network;

an internal link processing unit that executes a process for connecting to a terminal the identifier of which has been notified; and

a connection notifying unit that sends out a connection completion notice for notifying of connection completion, to multi-interface communication device as a transmission origin of the connection instruction, and sends out a self information notice for notifying of self network information, to the local network, responding to notices of connection completion from the external link processing unit and the internal link processing unit.

22. The multi-interface communication device of claim 21, further comprising a connection detecting unit that detects possibility of connection with the external network,

wherein the external link processing unit and the internal link processing unit start the connection process responding to a detection notice of connection possible from the connection detecting unit;

and

wherein the connection notifying unit sends out a connection instruction reply for notifying of starting a process for connecting with the external network, to a multi-interface communication device as a transmission origin of the connection instruction, responding to a detection notice of connection possible from the connection detecting unit.

23. The multi-interface communication device of claim 22,

wherein the instruction receiving unit notifies the connection detecting unit when further receiving a request parameter showing communication quality and communication performance;

and

wherein the connection detecting unit detects whether or not a requirement given by the request parameter is satisfied by the external network as a connection target.

24. The multi-interface communication device of claim 22, wherein the connection notifying unit sends out a connection instruction reply for notifying of disconnection with the external network, to a multi-interface communication device as a transmission origin of the connection instruction, responding to a detection notice of connection impossible from the connection detecting unit.

25. The multi-interface communication device of claim 24,

wherein the connection detecting unit always monitors possibility of connection with an external network and notifies the connection notifying unit when a state of connection possibility changes;

and

wherein the connection notifying unit, responding to the notice, sends out a connection possibility notice for notifying connection possibility to an other multi-interface communication device on the local network.

26. The multi-interface communication device of claim 25, wherein the connection possibility notice includes possibility of connection with the external network, an identifier specifying the self, and communication capacity of the external network.

27. The multi-interface communication device of claim 25, wherein the connection notifying unit, if having received an instant notice solicitation for soliciting instantly sending out the connection possibility notice, the connection instruction reply, and the connection completion notice, sends out the notices to a multi-interface communication device as a solicitation origin instantly when the messages are generated.

28. The multi-interface communication device of claim 21, wherein the connection notifying unit, after or instead of sending out the connection completion notice, notifies the local wireless network of a path switching instruction for instructing switching a multi-interface communication device used for relaying, on behalf of a multi-interface communication device as a transmission origin of the connection instruction.

42. The multi-interface communication device of claim 22, wherein the connection notifying unit, after or instead of sending out the connection completion notice, notifies the local wireless network of a path switching instruction for instructing switching a multi-interface communication device used for relaying, on behalf of a multi-interface communication device as a transmission origin of the connection instruction.

43. The multi-interface communication device of claim 23, wherein the connection notifying unit, after or instead of sending out the connection completion notice, notifies the local wireless network of a path switching instruction for instructing switching a multi-interface communication device used for relaying, on behalf of a multi-interface communication device as a transmission origin of the connection instruction.

44. The multi-interface communication device of claim 24, wherein the connection notifying unit, after or instead of sending out the connection completion notice, notifies the local wireless network of a path switching instruction for instructing switching a multi-interface communication device used for relaying, on behalf of a multi-interface communication device as a transmission origin of the connection instruction.

45. The multi-interface communication device of claim 25, wherein the connection notifying unit, after or instead of sending out the connection completion notice, notifies the local wireless network of a path switching instruction for instructing switching a multi-interface communication device used for relaying, on behalf of a multi-interface communication device as a transmission origin of the connection instruction.

46. The multi-interface communication device of claim 26, wherein the connection notifying unit, after or instead of sending out the connection completion notice, notifies the local wireless network of a path switching instruction for instructing switching a multi-interface communication device used for relaying, on behalf of a multi-interface communication device as a transmission origin of the connection instruction.

47. The multi-interface communication device of claim 27, wherein the connection notifying unit, after or instead of sending out the connection completion notice, notifies the local wireless network of a path switching instruction for instructing switching a multi-interface communication device used for relaying, on behalf of a multi-interface communication device as a transmission origin of the connection instruction.

29. A terminal comprising:

a receiving unit that receives a connection request from an unconnected multi-interface communication device and a path switching instruction for instructing path switching from a multi-interface communication device being connected to an other multi-interface communication device; and

a connection management unit that executes a process for connecting with a multi-interface communication device as a request origin according to the connection request notified from the receiving unit, and switches a relay destination to a connected multi-interface communication device according to the path switching instruction.