Method and apparatus for multicast routing in a network

• US 6,321,270 B1
• Filed: 09/27/1996
• Issued: 11/20/2001
• Est. Priority Date: 09/27/1996
• Status: Expired due to Term

• Current Assignee: Avaya Incorporated
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Crawley, Eric S.
• Primary Examiner(s): Burgess, Glenton B.
• Assistant Examiner(s): FIELDS, KENNETH WAYNE
• Application Number:
  US08/722,480
• Time in Patent Office: 1,880 Days
• Field of Search: 395/200.43, 395/200.53, 395/200.62, 395/200.68, 395/200.74, 370/390, 370/400, 370/255, 709/213, 709/223, 709/232, 709/238, 709/244
• US Class Current: 709/238
• CPC Class Codes: H04L 12/185 with management of multicast group membership
• CPC Class Codes: H04L 12/1877 Measures taken prior to transmission

Abstract

A system is provided for controlling a multicast session in a network having multiple network nodes. The system selects one of the network nodes as a control point associated with the multicast session. Identity of the control point is then advertised to all network nodes in a particular area. The control point determines multicast control information for the multicast session. Multicast control information determined by the control point is transmitted to the network nodes participating in the multicast session. The multicast control information may include network nodes participating in the multicast session, multicast reflection points, or instructions for transmitting multicast data to members of the multicast session. Updating of the multicast control information occurs in response to network changes. The system may provide a secondary control point that maintains a copy of control information associated with the multicast session.

Claims

1. A method for controlling a multicast session in a network using a network node operating as a control point, the network having a plurality of nodes, the method comprising:

advertising the control point identity to all nodes in the network including a first network node not participating in the multicast session and at least one network node participating in the multicast session;

determining multicast control information for the multicast session;

identifying the at least one network node participating in the multicast session;

contacting, by the first network node, the selected control point to request information regarding proper handling of multicast data received prior to receiving the multicast control information; and

transmitting, by the selected control point, the multicast control information to the first network node.

2. The method of claim 1 further including selecting one of the network nodes as a secondary control point associated with the multicast session.

3. The method of claim 2 wherein the secondary control point maintains a copy of the multicast control information determined by the control point.

4. The method of claim 2 further including transferring control of the multicast session from the control point to the secondary control point if the control point fails.

5. The method of claim 1 further including updating the multicast control information for the multicast session in response to network changes and transmitting the updated information to network nodes participating in the multicast session.

6. The method of claim 1 wherein the multicast control information includes instructions for transmitting multicast data to members of the multicast session.

7. The method of claim 1 wherein the network utilizes a switching system product.

8. The method of claim 1 wherein the network utilizes a transmission system product.

9. The method of claim 1, further comprising:

selecting a network node other than the control point as a distribution point for data messages of the multicast session.

10. The method of claim 1, wherein the multicast session is one of a plurality of multicast sessions, the plurality of multicast sessions including a second multicast session using a different set of network nodes than the first multicast session.

11. A communication device for controlling a multicast session in a network having a plurality of nodes, comprising:

a selection mechanism adapted to select one of the network nodes as a control point associated with the multicast session;

a control mechanism adapted to determine multicast control information for the multicast session, the control mechanism further adapted to transmit the multicast control information to network nodes participating in the multicast session; and

an error handling mechanism adapted to contact the control point, identified in a prior advertisement, to request information regarding proper handling of multicast data which the network nodes receive prior to receiving the multicast control information when the network node associated with the communication device is not participating in the multicast session.

12. The communication device of claim 11 wherein the selection mechanism is adapted to select one of the network nodes as a secondary control point associated with the multicast session, the secondary control point to maintain a copy of the multicast control information determined by the control point.

13. The communication device of claim 11 wherein the selection mechanism is a communication engine.

14. The communication device of claim 13 wherein the communication engine includes a central processing unit and a storage device.

15. The communication device of claim 14 wherein the storage device includes a Link State database.

16. The communication device of claim 11 is one of a switching system product and a transmission system product.

17. The communication device of claim 11, wherein the communication device is a router.

18. The communication device of claim 11, wherein the communication device is an asynchronous transfer mode (ATM) switch.

19. The communication device of claim 11, wherein the selection mechanism selects a network node other than the control point for a multicast data distribution point.

20. An apparatus for controlling a multicast session in a network having a plurality of nodes, comprising:

means for selecting one of the network nodes as a control point associated with the multicast session;

means for receiving information advertised by the control point;

means for selecting one of the network nodes as a secondary control point associated with the multicast session;

means for determining multicast control information for the multicast session;

means for transmitting the multicast control information to network nodes participating in the multicast session; and

means for contacting, by at least one network node not participating in the multicast session, the control point to request the multicast control information regarding proper handling of multicast data which the at least one network node received prior to receiving the multicast control information.

21. The apparatus of claim 20 further including means for selecting one of the network nodes as a secondary control point associated with the multicast session.

22. The apparatus of claim 20 wherein the secondary control point maintains a copy of the multicast control information determined by the control point.

23. The apparatus of claim 20 wherein control of the multicast session is transferred from the control point to the secondary control point if the control point fails.

24. The apparatus of claim 20, further comprising:

means for selecting a network node other than the control point as a multicast data distribution point for the multicast session.

25. A method for controlling a first multicast session in a network having a plurality of nodes, the method comprising:

selecting one of the network nodes as a control point associated with the first multicast session being one of a plurality of multicast sessions, the plurality of multicast sessions including the first multicast session and a second multicast session having different participating network nodes than the first multicast session;

determining multicast control information for the first multicast session;

transmitting the multicast control information to network nodes participating in the first multicast session;

receiving information that identifies the selected control point;

contacting the selected control point by at least one network node not participating in the first multicast session to request the multicast control information; and

sending, by the selected control point, the multicast control information to the at least one node, the multicast control information indicating proper handling of previously received multicast data.

26. A method for controlling a first and second multicast sessions in a network having a plurality of network nodes, the method comprising:

selecting one of the plurality of network nodes as a control point associated with the first and second multicast sessions;

identifying the selected control point to the plurality of network nodes; and

determining first and second multicast control information respectively for the first and second multicast sessions, wherein different network nodes of the plurality of network nodes are participating in the first and second multicast sessions;

contacting, by a network node of the plurality of network nodes that is not participating in the first multicast session, the selected control point to request the first multicast control information indicating a proper handling of multicast data received by the network node;

updating the first multicast control information; and

sending, by the selected control point, the updated first multicast control information to the network node.

27. The method of claim 26, wherein each of the first and second multicast sessions have a data distribution point other than the control point.

28. The method of claim 26, wherein the selecting of one of the plurality of network nodes as a control point further includes selecting one of the network nodes as a secondary control point associated with the first multicast session, the secondary control point maintains a copy of the first multicast control information.

29. The method of claim 28 further comprising transferring control of the first multicast session from the control point to the secondary control point if the control point fails.

30. The method of claim 26 firther comprising updating the first multicast control information for the first multicast session in response to network changes and transmitting the updated information to network nodes participating in the first multicast session.

31. The method of claim 26, wherein the first multicast control information includes identification of network nodes participating in the first multicast session.

32. The method of claim 26, wherein the first multicast control information includes multicast reflection point locations in the network.

33. The method of claim 26, wherein the first multicast control information includes instructions for transmitting multicast data to members of the first multicast session.