Network multicasting

• US 20040202164A1
• Filed: 04/08/2003
• Published: 10/14/2004
• Est. Priority Date: 04/08/2003
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Intel Corporation
• Inventors: Hooper, Donald F., Kalkunte, Suresh S.
• Granted Patent: US 7,391,772 B2
• Time in Patent Office: Days
• US Class Current: 370/390
• CPC Class Codes: H04L 12/1836 with heterogeneous network architecture
• CPC Class Codes: H04L 12/1886 with traffic restrictions for efficiency improvement, e.g. involving subnets or subdomains

Abstract

In general, in one aspect, the disclosure describes a technique of determining forwarding information for at least a sub-set of members of a multicast group, and sending, toward a downstream entity, at most a single copy of data to be multicasted to the sub-set of members and the determined forwarding information.

Claims

1. A method of multicasting data over a network, the method comprising:

determining forwarding information for at least a sub-set of members of a multicast group, the forwarding information corresponding to different egress interfaces of a downstream entity; and

sending, toward the downstream entity, at most a single copy of data to be multicasted to the sub-set of members and the determined forwarding information.

2. The method of claim 1, further comprising transmitting, from the downstream entity, multiple copies of the data to be multicasted via the downstream device egress interfaces identified by the forwarding information.

3. The method of claim 1, wherein the sub-set comprises a sub-group of members of a multicast group sharing a data rate.

4. The method of claim 1, further comprising sending, to the downstream entity, data of multiple protocol data unit headers.

5. The method of claim 4, further comprising, at the downstream entity, constructing multiple protocol data units using the multicast data and the data of multiple protocol data unit headers.

6. The method of claim 5, wherein the protocol data units include an Asynchronous Transfer Mode (ATM) cell having a header than includes a Virtual Path Identifier (VPI) and a Virtual Channel Identifier (VCI).

7. The method of claim 1, further comprising scheduling transmission via the multiple egress interfaces.

8. The method of claim 7, wherein the scheduling comprises synchronizing scheduling of egress interfaces used to carry PDUs to group members sharing a data rate.

9. The method of claim 7, wherein the scheduling comprises scheduling in accordance with bandwidth provisioned to the multicast group.

10. The method of claim 1, wherein the downstream device comprises a link layer device.

11. The method of claim 10, wherein the link layer device comprises a medium access controller (MAC).

12. The method of claim 1, further comprising storing control data for different multicast group sub-groups, the control data at least identifying egress interfaces for members of the multicast sub-groups.

13. A device, comprising:

at least one interface to a downstream entity;

logic to;

determine forwarding information for at least a sub-set of members of a multicast group, the forwarding information corresponding to different egress interfaces of a downstream entity; and

send, toward the downstream entity, at most a single copy of data to be multicasted to the sub-set of members and the determined forwarding information.

14. The device of claim 13, wherein the sub-set comprises a sub-group of members of a multicast group sharing a data rate.

15. The device of claim 13, further comprising logic to send, to the downstream entity, data of multiple protocol data unit headers.

16. The device of claim 15, wherein the headers comprise headers for Asynchronous Transfer Mode (ATM) cells than include a Virtual Path Identifier (VPI) and a Virtual Channel Identifier (VCI).

17. The device of claim 13, further comprising logic to schedule transmission via the multiple egress interfaces.

18. The device of claim 17, wherein the logic to schedule comprises logic to synchronize scheduling of egress interfaces used to carry PDUs to group members sharing a data rate.

19. The device of claim 17, wherein the logic to schedule comprises logic to schedule in accordance with bandwidth provisioned to the multicast group and rates of the egress interfaces.

20. The device of claim 19, wherein the multicast group is configured to operate in best-effort mode.

21. The device of claim 13, wherein the downstream device comprises a link layer device.

22. The device of claim 13, further comprising memory storing control data for different multicast group sub-groups, the control data at least identifying egress interfaces for members of the multicast sub-groups.

23. The device of claim 13, wherein the logic comprises multiple Reduced Instruction Set Computing (RISC) processors programmed to implement the logic.

24. A device, comprising:

a collection of egress interfaces;

logic to;

receive a single copy of data to be multicasted to at least a sub-set of members of a multicast group and receive forwarding information for the at least a sub-set of members of the multicast group, the forwarding information corresponding to at least a subset of the collection egress interfaces; and

transmit the data to be multicasted via more than one egress interface based on the forwarding information.

25. The device of claim 24, wherein the forwarding information comprises forwarding information corresponding to a sub-group of members of a multicast group sharing a data rate.

26. The device of claim 24, further comprising logic to receive multiple protocol data unit headers.

27. The device of claim 26, further comprising logic to construct multiple protocol data units using the multicast data and the data that identifies multiple protocol data unit headers.

28. The device of claim 27, wherein the protocol data units include an Asynchronous Transfer Mode (ATM) cell having a header than includes a Virtual Path Identifier (VPI) and a Virtual Channel Identifier (VCI).

29. A computer program product, disposed on a computer readable medium, the product including instructions to cause a processor to:

determine forwarding information for at least a sub-set of members of a multicast group, the forwarding information corresponding to different egress interfaces of a downstream entity; and

send, toward the downstream entity, at most a single copy of data to be multicasted to the sub-set of members and the determined forwarding information.

30. The computer program of claim 29, wherein the sub-set comprises a sub-group of members of a multicast group sharing a data rate.

31. The computer program of claim 29, further comprising instructions to cause the processor to send, toward the downstream entity, data that identifies multiple protocol data unit headers.

32. The computer program of claim 29, further comprising instructions for causing a processor to schedule transmission via the multiple egress interfaces.

33. The computer program of claim 32, wherein the instructions for causing the processor to schedule comprise instructions that cause the processor to synchronize scheduling of egress interfaces used to carry PDUs to group members sharing a data rate.

34. The computer program of claim 32, wherein the instructions for causing the processor to schedule transmission comprise instructions for causing the processor to schedule transmission in accordance with bandwidth provisioned to the multicast group.

35. The computer program of claim 29, wherein the instructions to cause the processor to send the multicast data to the downstream entity comprise instructions to cause the processor to send the multicast data, at most, once per sub-group.

36. A system, comprising:

a network processor having multiple Reduced Instruction Set Computing (RISC) packet processors, the network processor to execute instructions to;

determine forwarding information for at least a sub-set of members of a multicast group, the forwarding information corresponding to different egress interfaces of a downstream entity; and

send, toward the downstream entity having multiple egress interfaces, at most a single copy of data to be multicasted to the sub-set of members and the determined forwarding information; and

an Ethernet medium access controller (MAC) including logic to;

receive the data to be multicasted and the forwarding information; and

transmit the data to be multicasted via the egress interfaces identified by the forwarding information.

37. The system of claim 36,

wherein the packet processor instructions further comprise instructions to transmit data for multiple protocol data unit headers to the Ethernet medium access controller;

and

wherein the Ethernet medium access controller logic comprises logic to construct multiple protocol data units from the data to be multicasted and the data for multiple protocol data unit headers.

38. The system of claim 36, wherein the at least a sub-set of member of a multicast sub-group comprise members of a multicast group sharing a data rate.

39. The system of claim 36, wherein the instructions comprise instructions to synchronize scheduling of transmission via the multiple egress interfaces.