MULTICAST TRAFFIC GENERATION USING HIERARCHICAL REPLICATION MECHANISMS FOR DISTRIBUTED SWITCHES

• US 20130242992A1
• Filed: 12/07/2012
• Published: 09/19/2013
• Est. Priority Date: 03/14/2012
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Basso, Claude, Greenfield, Todd A., Walk, Bruce M.
• Granted Patent: US 8,937,959 B2
• Time in Patent Office: Days
• US Class Current: 370/390
• CPC Class Codes: H04L 45/16 Multipoint routing
• CPC Class Codes: H04L 49/201 Multicast operation; Broadcast operation
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches
• CPC Class Codes: H04L 49/70 Virtual switches

Abstract

A distributed switch may include a hierarchy with one or more levels of surrogate sub-switches (and surrogate bridge elements) that enable the distributed switch to scale bandwidth based on the size of the membership of a multicast group. When a sub-switch receives a multicast data frame, it forwards the packet to one of the surrogate sub-switches. Each surrogate sub-switch may then forward the packet to another surrogate in a different hierarchical level or to a destination computing device. Because the surrogates may transmit the data frame in parallel using two or more connection interfaces, the bandwidth used to forward the multicast packet increases for each surrogate used.

Claims

1. A method of forwarding a multicast data frame in a distributed switch comprising a plurality of switches, comprising:

receiving a multicast data frame on a receiving port of an ingress switch in the distributed switch;

determining destination switches in the distributed switch that should receive at least a portion of the multicast data frame; and

forwarding the portion of the multicast data frame to a first surrogate switch in a hierarchy, wherein the first surrogate switch is assigned in the hierarchy to forward the portion to at least one of;

one of the destination switches and a second surrogate switch in the hierarchy,

wherein the hierarchy increases an available bandwidth for forwarding the portion of the data frame in the distributed switch based on a number of the destination switches.

2. The method of claim 1, further comprising:

forwarding the portion of the multicast data frame from the first surrogate switch to the second surrogate switch, wherein the first surrogate switch is assigned in the hierarchy to a subset of the plurality of switches and wherein the second surrogate switch is assigned to a subset of the subset of switches assigned to the first surrogate switch.

3. The method of claim 2, wherein the first and second surrogate switches increase the available bandwidth used for forwarding the portion of the data frame within the distributed switch by forwarding the portion of the data frame to at least two switches in the distributed switch in parallel using at least two respective connection interfaces.

4. The method of claim 2, wherein the one destination switch is assigned to both the first surrogate switch and the second surrogate switch in the hierarchy.

5. The method of claim 1, wherein the first surrogate switch is one of the plurality of switches in the distributed switch, wherein each of the plurality of switches include at least two bridge elements that are each associated with at least one connection interface on the switches, and

wherein the portion of the multicast data frame is at least a portion of a payload of the multicast data frame.

6. The method of claim 5, wherein the receiving port of the ingress switch is associated with a first bridge element, wherein at least one connection interface in the ingress switch is configured to forward the portion of the multicast data frame from the first bridge element to a second bridge element in the ingress switch, and

wherein a connection interface of the first surrogate switch that receives the forwarded portion from the ingress switch is associated with a third bridge element, wherein at least one connection interface of the first surrogate switch is configured to forward the portion from the third bridge element to a fourth bridge element in the first surrogate switch.

7. The method of claim 5, further comprising, selecting one of the bridge elements of the first surrogate switch as a surrogate bridge element that receives the forwarded portion from the ingress switch, wherein the surrogate bridge element is selected based on a performance metric.