Method and apparatus for bypass routing of multicast data packets and avoiding replication to reduce overall switch latency

A device for routing multicast data packets, said device comprising:

• an ingress port;
• a plurality of egress ports;
• and
• bypass logic coupled to said ingress port and configured to:
• retrieve a multicast data packet of said multicast data packets;
• receive a status signal indicating availability of each egress port of said plurality of egress ports, wherein retrieving said multicast data packet is performed in parallel to said reception of said status signal;
• from said plurality of egress ports, identify a first set of egress ports to be used for transmitting said multicast data packet, wherein said first set of egress ports comprises two or more egress ports;
• based on said status signal, identify a second set of egress ports that are available, selected from said first set of egress ports;
• determine a number of copies of said multicast data packet to be replicated based on information contained in said multicast data packet, wherein said number of copies of said multicast data packet corresponds to a number of egress ports comprised in said second set of egress ports;
• and
• if said second set of egress ports contains some ports that are less than all ports of said first set of egress ports:
• bypass a set of processing operations for said some ports prior to transmission of said multicast data packet, and directly transmit said multicast data packet to said some ports.

A system comprising:

• a processor;
• and
• a memory coupled to said processor and storing instructions that when executed by said processor, implement a method of routing multicast data packets, said method comprising:
• retrieving a multicast data packet of said mutlicast data packets;
• receiving a status signal indicating availability of each egress port of a plurality of egress ports, wherein said retrieving said multicast data packet is performed in parallel to said receiving said status signal;
• identifying a first set of said egress ports to be used for transmitting said multicast data packet, wherein said first set of egress ports comprises two or more egress ports of said plurality of egress ports;
• based on said status signal, identifying a second set of egress ports that are available, selected from said first set of egress ports, wherein said status signal indicates per-egress port congestion, wherein an egress port in said first set of egress ports indicated as congested according to said status signal is not included in said second set of egress ports that are available;
• determining a number of copies of said multicast data packet to be replicated based on information contained in said multicast data packet, wherein said number of copies of said multicast data packet corresponds to a number of egress ports comprised in said second set of egress ports;
• and
• if said second set of egress ports contains some ports that is less than all ports of said first set of egress ports:
• bypassing a set of processing operations for said some ports prior to transmission of said multicast data packet, and directly transmitting said multicast data packet to said some ports.