Method and apparatus for forwarding multicast data by relaying IGMP group membership

• US 6,654,371 B1
• Filed: 04/15/1999
• Issued: 11/25/2003
• Est. Priority Date: 04/15/1999
• Status: Expired due to Term

• Current Assignee: Avaya Management L.P. (Avaya Incorporated)
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Dunstan, Adam, DiBurro, Larry, Li, Yunhou
• Primary Examiner(s): Olms, Douglas W.
• Assistant Examiner(s): VANDERPUYE, KENNETH N
• Application Number:
  US09/293,495
• Time in Patent Office: 1,685 Days
• Field of Search: 370/390, 370/432, 370/312, 370/401, 370/381, 370/400
• US Class Current: 370/390
• CPC Class Codes: H04L 12/185 with management of multicast group membership

Abstract

A method, apparatus and article of manufacture for forwarding multicast data by relaying IGMP group membership. A router is used to build a database of a plurality of interfaces and corresponding multicast groups, and the database is stored on the router. Information from the database is reported upstream to a multicast router. Multicast data is received from the multicast router and distributed to the plurality of interfaces based upon the database.

Claims

1. In a data communications network, a method of routing multicast packets between a multicast router and endstations without using a multicast protocol, the method comprising:

using a network relay to build a database of a plurality of interfaces coupled to the endstations and corresponding groups of endstations to transceive multicast data;

reporting group information from the database upstream to a querying multicast router in response to its query;

receiving multicast data from the querying multicast router for distribution to the groups of endstations to transceive multicast data; and

distributing the multicast data to the plurality of interfaces based upon database information of the plurality of interfaces coupled to the endstations and corresponding groups of endstations to transceive multicast data.

2. The method of claim 1 further comprising:

storing the database in the network relay.

3. The method of claim 1 further comprising:

distributing group packet information to the plurality of interfaces based upon the database information of the plurality of interfaces coupled to the endstations and corresponding groups of endstations to transceive multicast data.

4. The method of claim 1 further comprising:

distributing protocol information to a backup network relay.

5. The method of claim 4 wherein,

the network relay includes a router and the backup network relay includes a hot standby router.

16. The method of claim 1 further comprising:

broadcasting a query through the plurality of interfaces to endstations to determine the presence of groups.

17. The method of claim 16 further comprising:

receiving group membership report messages at the plurality of interfaces from endstations in response to the broadcasting of the query, the group membership reports indicating the presence of groups.

18. The method of claim 1 wherein,

the network relay is an Internet Group Management Protocol (IGMP) network relay device and the protocol executed by the endstations is Internet Group Management Protocol (IGMP), the corresponding groups of endstations desiring to transceive multicast data are IGMP groups, and IGMP group membership is reported from the database upstream to a querying multicast router.

6. An apparatus for routing multicast packets between a multicast router and endstations without having the apparatus execute a multicast protocol, the apparatus comprising:

a network relay having a processor;

a database builder logically coupled to the processor to build a database of a plurality of interfaces coupled to the endstations and corresponding groups of endstations to transceive multicast data;

a database reporter logically coupled to the processor to report group information from the database upstream to a querying multicast router in response to its query;

a database receiver logically coupled to the processor to receive multicast data from the querying multicast router for distribution to the groups of endstations to transceive multicast data; and

a database distributor logically coupled to the processor to distribute the multicast data to the plurality of interfaces based upon database information of the plurality of interfaces coupled to the endstations and corresponding groups of endstations to transceive multicast data.

7. The apparatus of claim 6 further comprising:

a memory logically coupled to the processor to store the database in the network relay.

8. The apparatus of claim 6 further comprising:

a packet distributor to distribute group packet information to the plurality of interfaces based upon the database information of the plurality of interfaces coupled to the endstations and corresponding groups of endstations to transceive multicast data.

9. The apparatus of claim 6 further comprising:

a packet distributor to distribute protocol information to a backup network relay.

10. The apparatus of claim 9 wherein,

the network relay includes a router and the backup network relay includes a hot standby router.

11. An article of manufacture for use in a computer system to route multicast packets between a multicast router and endstations using a network relay without the network relay executing a multicast protocol, the article of manufacture comprising a computer usable medium having computer readable program code means embodied in the medium, the program code means including:

computer readable program code means embodied in the computer usable medium for causing a computer to use the network relay to build a database of a plurality of interfaces coupled to the endstations and corresponding groups of endstations to transceive multicast data;

computer readable program code means embodied in the computer usable medium for causing a computer to report group information from the database upstream to a querying multicast router in response to its query;

computer readable program code means embodied in the computer usable medium for causing a computer to receive multicast data from the querying multicast router for distribution to the groups of endstations to transceive multicast data; and

computer readable program code means embodied in the computer usable medium for causing a computer to distribute the multicast data to the plurality of interfaces based upon database information of the plurality of interfaces coupled to the endstations and corresponding groups of endstations to transceive multicast data.

12. The article of manufacture of claim 11 further comprising:

computer readable program code means embodied in the computer usable medium for causing a computer to store the database in the network relay.

13. The article of manufacture of claim 11 further comprising:

computer readable program code means embodied in the computer usable medium for causing a computer to distribute group packet information to the plurality of interfaces based upon the database information of the plurality of interfaces coupled to the endstations and corresponding groups of endstations to transceive multicast data.

14. The article of manufacture of claim 11 further comprising:

computer readable program code means embodied in the computer usable medium for causing a computer to distribute protocol information to a backup network relay.

15. The article of manufacture of claim 14 wherein,

the network relay includes a router and the backup network relay includes a hot standby router.

19. The article of manufacture of claim 11 further comprising:

computer readable program code means embodied in the computer usable medium for causing a computer to broadcast a query through the plurality of interfaces to endstations to determine the presence of groups.

20. The article of manufacture of claim 19 further comprising:

computer readable program code means embodied in the computer usable medium for causing a computer to receive group membership report messages at the plurality of interfaces from endstations in response to the broadcasting of the query, the group membership reports indicating the presence of groups.

21. The article of manufacture of claim 11 wherein,

the network relay is an Internet Group Management Protocol (IGMP) network relay device and the protocol executed by the endstations is Internet Group Management Protocol (IGMP), the corresponding groups of endstations desiring to transceive multicast data are IGMP groups, and IGMP group membership is reported from the database upstream to a querying multicast router.

22. An IGMP network relay for routing multicast packets between a multicast router and endstations, the IGMP network relay comprising:

a first processor;

a first memory coupled to the first processor;

a first upstream interface to couple to the multicast router;

at least one downstream interface to couple to the endstations; and

wherein, the IGMP network relay functions as an IGMP host on the first upstream interface and as an IGMP router on the at least one downstream interface.

23. The IGMP network relay of claim 22 wherein,

the IGMP network relay broadcasts a query over the at least one downstream interface to determine IGMP group membership of endstations coupled to the at least one downstream interface.

24. The IGMP network relay of claim 23 wherein,

the IGMP network relay receives IGMP group membership report messages over the at least one downstream interface to indicate the IGMP group membership of endstations coupled to the at least one downstream interface.

25. The IGMP network relay of claim 22 wherein,

the IGMP network relay receives a query over the first upstream interface requesting IGMP group membership of the IGMP network relay.

26. The IGMP network relay of claim 25 wherein,

the IGMP network relay transmits a group report message over the first upstream interface to indicate the IGMP group membership of endstations coupled to the at least one downstream interface.

27. The IGMP network relay of claim 22 further comprising:

a second upstream interface to couple to the multicast router through a second connection differing from a first connection.

28. The IGMP network relay of claim 22 further comprising:

a second processor;

a second memory coupled to the second processor;

a second upstream interface to couple to the multicast router;

another at least one downstream interface to couple to the endstations; and

wherein, the second processor, the second memory, the second upstream interface, and the another at least one downstream interface provide hot standby redundancy.