Method and system for multicast traffic reduction

• US 6,977,891 B1
• Filed: 06/30/2001
• Issued: 12/20/2005
• Est. Priority Date: 06/30/2001
• Status: Active Grant

• Current Assignee: Extreme Networks, Inc.
• Original Assignee: Extreme Networks, Inc.
• Inventors: Saravanan, Desikan, Ranjan, Ashish
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): Le, Viet
• Application Number:
  US09/895,110
• Time in Patent Office: 1,634 Days
• Field of Search: 370/229, 370235-236, 370/236.2, 370/312, 370351-353, 370355-356, 370/395.31, 370/395.52, 370400-401, 370/432, 370/381
• US Class Current: 370/229
• CPC Class Codes: H04L 12/18 for broadcast or conference , e.g. multicast
• 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 45/16 Multipoint routing
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]

Abstract

A method is provided to reduce multicast traffic by snooping IGMP control packets on a packet-forwarding device. A multicast traffic reducer includes an IGMP proxy, which operates in conjunction with an IGMP snooper to intercept selected IGMP control packets and generate proxy IGMP control packets in their place. The IGMP proxy may include an IGMP query batcher to consolidate IGMP queries to multicast host groups, an IGMP query responder to consolidate host responses to the IGMP queries to multicast host groups, and/or an IGMP leave forwarder to manage host IGMP leave packets. The IGMP proxy consolidates or discards host-generated IGMP control packets and timely generates IGMP proxy control packets in their place. The IGMP proxy further includes an IGMP layer-2 query generator to initiate IGMP queries for a layer-2 router multicast application.

Claims

1. A method, comprising:

snooping group management query packets on a packet forwarding device, the queries associated with a transmission of multicast traffic to a host group in communication with the device; and

processing the queries, including;

batching multicast queries of a subset of the members of the host group; and

transmitting each batch of multicast queries to each of the subsets of the members of the host group in a staggered fashion.

2. The method of claim 1, wherein the queries are received from a router that transmits the multicast traffic.

3. The method of claim 1, wherein the queries are generated by the packet forwarding device.

4. A method, comprising:

snooping group management query response packets on a packet forwarding device, the responses associated with a transmission of multicast traffic to a host group in communication with the device; and

processing the responses including;

determining whether one or more response indicates that a member of the host group should continue to receive the transmission of multicast traffic;

generating a single proxy response in accordance with the determination; and

transmitting the proxy response on behalf of the host group.

5. An apparatus, comprising:

a packet forwarding device, the packet forwarding device in communication with a host group; and

a multicast traffic reducer coupled with the packet forwarding device, the multicast traffic reducer to;

snoop group management query packets on the packet forwarding device, the queries associated with a transmission of multicast traffic to the host group; and

process the queries to;

batch multicast queries of a subset of the members of the host group; and

transmit each batch of multicast queries to each of the subsets of the members of the host group in a staggered fashion.

6. The apparatus of claim 5, wherein the queries are received from a router that transmits the multicast traffic.

7. The apparatus of claim 5, wherein the queries are generated by the packet forwarding device.

8. An apparatus, comprising:

a packet forwarding device, the packet forwarding device in communication with a host group; and

a multicast traffic reducer coupled with the packet forwarding device, the multicast traffic reducer to;

snoop group management query response packets on the packet forwarding device, the responses associated with a transmission of multicast traffic to the host group; and

process the responses to;

determine whether one or more response indicates that a member of the host group should continue to receive the transmission of multicast traffic;

generate a single proxy response in accordance with the determination; and

transmit the proxy response on behalf of the host group.

9. An article of manufacture, comprising:

a machine-accessible medium providing content that, when accessed by a machine, causes the machine to;

snoop group management control query packets on a packet forwarding device, the queries associated with a transmission of multicast traffic to a host group in communication with the device; and

process the queries to;

batch multicast queries of a subset of the members of the host group; and

transmit each batch of multicast queries to each of the subsets of the members of the host group in a staggered fashion.

10. The article of manufacture of claim 9, wherein the query is received from a router that transmits the multicast traffic.

11. The article of manufacture of claim 9, wherein the query is generated by the packet forwarding device.

12. An article of manufacture comprising:

a machine-accessible medium providing content that, when accessed by a machine, causes the machine to;

snoop group management control response packets on a packet forwarding device, the responses associated with a transmission of multicast traffic to a host group in communication with the device; and

process the responses to;

determine whether one or more response indicates that a member of the host group should continue to receive the transmission of multicast traffic;

generate a single proxy response in accordance with the determination; and

transmit the proxy response on behalf of the host group.