MULTICAST PACKET ROUTING VIA CROSSBAR BYPASS PATHS

• US 20150207638A1
• Filed: 01/31/2014
• Published: 07/23/2015
• Est. Priority Date: 01/21/2014
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: BASSO, Claude, CHRYSOS, Nikolaos, MINKENBERG, Cyriel J., RUDQUIST, Mark L., SHEDIVY, David A., VANDERPOOL, Brian T.
• Granted Patent: US 9,571,292 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04L 12/18 for broadcast or conference , e.g. multicast
• CPC Class Codes: H04L 47/62 characterised by scheduling criteria
• CPC Class Codes: H04L 49/101 using crossbar or matrix
• CPC Class Codes: H04L 49/201 Multicast operation; Broadcast operation

Abstract

An approach is described for routing data to a plurality of output terminals via a integrated switch router including a crossbar switch having both a crossbar and a plurality of crossbar bypass lines. Whereas the crossbar may connect each input of the crossbar switch to each output of the crossbar switch, each of the plurality of crossbar bypass lines may connect a single input of the crossbar switch to a corresponding single output of the crossbar switch. According to such approach, a replicated copy of a multicast packet may be forwarded to an output terminal via a crossbar bypass line in parallel with other data forwarded via the crossbar, thus increasing integrated switch router bandwidth.

Claims

1. A method of routing data to a plurality of output terminals via an integrated switch router, wherein the integrated switch router comprises a broadcast network, a crossbar switch having a crossbar and a plurality of crossbar bypass lines, and a plurality of multicast replication buffers communicatively connected to the broadcast network, wherein each of the plurality of multicast replication buffers respectively corresponds to one of the plurality of crossbar bypass lines, and wherein the method comprises:

receiving a multicast packet from an input terminal;

forwarding a payload of the multicast packet through the broadcast network;

forwarding each header of the multicast packet through the broadcast network; and

forwarding, by operation of one or more processors, replicated copies of the multicast packet through the crossbar switch to the plurality of output terminals.

2. The method of claim 1, wherein forwarding the payload of the multicast packet through the broadcast network comprises facilitating a broadcast of the payload to a payload queue of each of the plurality of multicast replication buffers.

3. The method of claim 1, wherein forwarding each header of the multicast packet through the broadcast network comprises:

for each header of the multicast packet;

upon determining that a header queue of a multicast replication buffer corresponding to a crossbar bypass line among the plurality of crossbar bypass lines having a path to a destination output terminal designated in the header is available, facilitating transmission of the header to the corresponding multicast replication buffer, and storing the header in the header queue of the corresponding multicast replication buffer; and

upon determining that a header queue of a multicast replication buffer corresponding to a crossbar bypass line among the plurality of crossbar bypass lines having a path to the destination output terminal is not available, facilitating transmission of the header to a multicast replication buffer among the plurality of multicast replication buffers having a header queue with a lowest backlog, and storing the header in the header queue with the lowest backlog.

4. The method of claim 1, wherein forwarding replicated copies of the multicast packet through the crossbar switch to the plurality of output terminals comprises:

for each header of the multicast packet;

facilitating replication of a copy of the multicast packet at the multicast replication buffer at which the header is stored;

upon determining that the multicast replication buffer at which the header is stored corresponds to a crossbar bypass line among the plurality of crossbar bypass lines having a path to a destination output terminal designated in the header, facilitating transmission of the replicated copy to the destination output terminal via the crossbar bypass line; and

upon determining that that the multicast replication buffer at which the header is stored does not correspond to a crossbar bypass line among the plurality of crossbar bypass lines having a path to the destination output terminal, facilitating transmission of the replicated copy to the destination output terminal via the crossbar.

5. The method of claim 4, further comprising:

forwarding data via the crossbar in parallel with a replicated copy of the multicast packet forwarded via a crossbar bypass line among the plurality of crossbar bypass lines.

6. The method of claim 1, wherein the crossbar connects each input among a plurality of inputs of the crossbar switch to each output among a plurality of outputs of the crossbar switch, and wherein each of the plurality of crossbar bypass lines connects a single input among the plurality of inputs to a single output among the plurality of outputs.