Node device and scheme for sharing common virtual connection indentifier between end-nodes

• US 6,490,622 B1
• Filed: 03/11/1998
• Issued: 12/03/2002
• Est. Priority Date: 03/11/1997
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Nagami, Kenichi, Matsuzawa, Shigeo, Katsube, Yasuhiro
• Primary Examiner(s): Harrell, Robert B.
• Assistant Examiner(s): WILLETT, STEPHAN F
• Application Number:
  US09/038,159
• Time in Patent Office: 1,728 Days
• Field of Search: 709/225, 709/238, 370/397, 370/399, 370/409
• US Class Current: 709/225
• CPC Class Codes: H04L 2012/563 Signalling, e.g. protocols, reference model
• CPC Class Codes: H04L 2012/5642 Multicast/broadcast/point-multipoint, e.g. VOD
• CPC Class Codes: H04Q 11/0478 Provisions for broadband connections

Abstract

A scheme for sharing a common virtual connection identifier between end-nodes, which enable sharing of a common identifier of a sufficient information length at both end-nodes of a virtual connection. In this scheme, the first message containing a first identifier for provisionally identifying a virtual connection commonly between neighboring nodes is exchanged between neighboring nodes, at a time of setting up the virtual connection. Then, the second message containing a second identifier having a larger information size than the first identifier for formally identifying the virtual connection commonly between neighboring nodes, in a form that enables establishing of a correspondence between the first identifier and the second identifier, is exchanged between neighboring nodes through another virtual connection different from the virtual connection to be set up. The correspondence between the first identifier and the second identifier is managed at each node according to the first message and the second message so as to share the second identifier between neighboring nodes.

Claims

1. A node device, comprising:

an interface for a virtual connection-oriented network;

a first message exchange unit configured to exchange a first message which contains a first identifier for provisionally identifying a virtual connection between said node device and a neighboring node device, at a time of setting up the virtual connection through the interface, the first identifier being a common identifier to be used in provisionally identifying the virtual connection at both of said node device and the neighboring node device;

a management unit configured to manage a correspondence between the first identifier and a second identifier having a larger information size than the first identifier for formally identifying the virtual connection between said node device and the neighboring node device, the second identifier being another common identifier to be used in formally identifying the virtual connection at both of said node device and the neighboring node device; and

a second message exchange unit configured to transmit or receive a second message which contains the second identifier in a form that enables establishing of a correspondence between the first identifier and the second identifier, through another virtual connection different from the virtual connection to be set up;

wherein the management unit manages the virtual connection by the second identifier and makes the first identifier available for other virtual connections, after the virtual connection is set up by the exchange of the first message by the first message exchange unit and the second identifier is shared between said node device and the neighboring node device by exchange of the second message by the second message exchange unit.

2. The node device of claim 1, wherein the first message exchange unit exchanges the first message in a form of a datalink layer signaling message, and the second message exchange unit exchanges the second message in a form of a network layer message.

3. The node device of claim 1, wherein the second message exchange unit also transmits or receives a flow identification information for identifying a flow of packets to be transmitted through the virtual connection.

4. The node device of claim 3, wherein the second message exchange unit exchanges the second message which also contains the flow identification information in a form that enables establishing of a correspondence between the flow identification information and the first identifier or the second identifier.

5. The node device of claim 3, wherein the second message exchange unit also transmits or receives a third message which contains the flow identification information in a form that enables establishing of a correspondence between the flow identification information and the first identifier or the second identifier.

6. The node device of claim 3, wherein the interface transmits packets belonging to the flow through the virtual connection, after the second identifier and the flow identification information are shared between said node device and the neighboring node device by exchange of the second message by the second message exchange unit.

7. The node device of claim 3, wherein the management unit releases the virtual connection through the interface and makes the second identifier available for another virtual connection when transmission of packets belonging to the flow is judged to be unnecessary.

8. The node device of claim 3, wherein the management unit transmits or receives a message for removing a correspondence between the flow identification information and the second identifier through the second message exchange unit while maintaining the virtual connection when transmission of packets belonging to the flow is judged to be unnecessary, and makes the virtual connection available for transmission of packets belonging to another flow.

9. The node device of claim 3, wherein the interface interprets packets received through the virtual connection as packets belonging to the flow.

10. The node device of claim 1, wherein the management unit maintains the first identifier for the virtual connection even after the virtual connection is set up by exchange of the first message by the first message exchange unit and the second identifier is shared between said node device and the neighboring node device by exchange of the second message by the second message exchange unit, when there is a possibility for subsequently adding a new leaf to the virtual connection.

11. A method for sharing a common virtual connection identifier between neighboring nodes, comprising the steps of:

exchanging a first message between the neighboring nodes, the first message containing a first identifier for provisionally identifying a virtual connection between the neighboring nodes, at a time of setting up the virtual connection, the first identifier being a common identifier to be used in provisionally identifying the virtual connection at both of said node device and the neighboring node device;

exchanging a second message between the neighboring nodes, the second message containing a second identifier having a larger information size than the first identifier for formally identifying the virtual connection between the neighboring nodes, in a form that enables establishing of a correspondence between the first identifier and the second identifier, through another virtual connection different from the virtual connection to be set up, the second identifier being another common identifier to be used in formally identifying the virtual connection at both of said node device and the neighboring node device; and

managing a correspondence between the first identifier and the second identifier at each of the neighboring nodes according to the first message and the second message so as to share the second identifier between the neighboring nodes, and managing the virtual connection by the second identifier and making the first identifier available for other virtual connections after the virtual connection is set up by the exchange of the first message and the second identifier is shared between the neighboring nodes by exchange of the second message.

12. The method of claim 11, wherein the first message and the second message are transmitted from an upstream node to a downstream node among the neighboring nodes.

13. The method of claim 11, wherein the first message is transmitted from an upstream node to a downstream node among the neighboring nodes, and the second message is transmitted from the downstream node to the upstream node.

14. The method of claim 11, wherein the first message is transmitted from a downstream node to an upstream node among the neighboring nodes, and the second message is transmitted from the upstream node to the downstream node.

15. The method of claim 11, wherein the first message and the second message are transmitted from a downstream node to an upstream node among the neighboring nodes.

16. The method of claim 11, wherein the first message is exchanged before the second message is exchanged.

17. The method of claim 11, wherein the first message is exchanged to set up the virtual connection after the second message is exchanged.

18. The method of claim 11, wherein the first message is exchanged in a form of a datalink layer signaling message, and the second message is exchanged in a form of a network layer message.

19. The method of claim 11, further comprising the step of:

exchanging a flow identification information for identifying a flow of packets to be transmitted through the virtual connection between the neighboring nodes.

20. The method of claim 19, wherein the flow identification information is exchanged by the second message which also contains the flow identification information in a form that enables establishing of a correspondence between the flow identification information and the first identifier or the second identifier.

21. The method of claim 19, wherein the flow identification information is exchanged by a third message which contains the flow identification information in a form that enables establishing of a correspondence between the flow identification information and the first identifier or the second identifier.

22. The method of claim 19, further comprising the step of:

transmitting packets belonging to the flow through the virtual connection, after the second identifier and the flow identification information are shared between the neighboring nodes by exchange of the second message.

23. The method of claim 19, wherein the managing step also releases the virtual connection and makes the second identifier available for other virtual connections when transmission of packets belonging to the flow is judged to be unnecessary.

24. The method of claim 19, wherein the managing step also transmits or receives a message for removing a correspondence between the flow identification information and the second identifier while maintaining the virtual connection when transmission of packets belonging to the flow is judged to be unnecessary, and makes the virtual connection available for transmission of packets belonging to another flow.

25. The method of claim 19, further comprising the step of:

interpreting packets received through the virtual connection as packets belonging to the flow at each node.

26. The method of claim 11, wherein the managing step also maintains the first identifier for the virtual connection even after the virtual connection is set up by exchange of the first message and the second identifier is shared between the neighboring nodes by exchange of the second message, when there is a possibility for subsequently adding a new leaf to the virtual connection.

27. A computer usable medium having computer readable program codes embodied therein for causing a computer at a node device to function as a system that enables sharing of a common virtual connection identifier between neighboring nodes, the computer readable program codes include:

a first computer readable program code for causing said computer to exchange a first message which contains a first identifier for provisionally identifying a virtual connection between said node device and a neighboring node device, at a time of setting up the virtual connection, the first identifier being a common identifier to be used in provisionally identifying the virtual connection at both of said node device and the neighboring node device;

a second computer readable program code for causing said computer to manage a correspondence between the first identifier and a second identifier having a larger information size than the first identifier for formally identifying the virtual connection between said node device and the neighboring node device, the second identifier being another common identifier to be used in formally identifying the virtual connection at both of said node device and the neighboring node device; and

a third computer readable program code for causing said computer to transmit or receive a second message which contains the second identifier in a form that enables establishing of a correspondence between the first identifier and the second identifier, through another virtual connection different from the virtual connection to be set up;

wherein the second computer readable program code manages the virtual connection by the second identifier and makes the first identifier available for other virtual connections, after the virtual connection is set up by the exchange of the first message by the first computer readable program code and the second identifier is shared between said node device and the neighboring node device by exchange of the second message by the third computer readable program code.

28. The article of manufacture of claim 27, wherein the first computer readable program code causes said computer to exchange the first message by utilizing an existing computer program for signaling message exchange.