Network switch with mutually coupled look-up engine and network processor
View Patent ↗A network switch includes a look-up engine for obtaining associated data in response to a header portion of a packet and an interlinked network processor such as a RISC for performing a processing function on the header portion or the associated data. Both look-up engine and the network processor may modify a destination port bitmask. The network processor may implement additional packet header processing required for replication or server load balancing.
1. A method of operating a network switch for receiving data packets including header portions and for selectively forwarding said data packets, said method comprising:
retrieving, by a look-up engine, a port bitmask in response to receipt of a header portion of a received packet, wherein the port bitmask comprises a plurality of bits that correspond to respective ports in the network switch and wherein the states of the plurality of bits indicate whether the respective ports are to receive a copy of the received packet;
executing, at a network processor, a processing function in response to at least one of said received packet and retrieval of said port bitmask, said processing function comprising:
generating a modified port bitmask of the retrieved port bitmask;
providing a release signal corresponding to said received packet; and
providing the modified port bitmask to the lookup engine; and
forwarding the received packet only in response to receiving, at the look-up engine, the modified port bitmask and a release signal corresponding to said received packet.
2. The method according to claim 1 wherein each of said lookup engine and said network processor receive a first indication that the packet has been received.
3. The method according to claim 2 wherein said look-up engine provides for said network processor a second indication, said second indication indicating that said port bitmask has been obtained.
4. The method according to claim 3 wherein said network processor is operative, in response to said first indication, to execute said processing function and to provide to said look-up engine a third indication, said third indication indicating that said processing function has been executed.
5. The method according to claim 1 wherein said network processor performs the processing function in parallel with the retrieving by the lookup engine.
6. The method according to claim 1 wherein the lookup engine forwards a plurality of copies of the received packet in response to one of a plurality of modified port bitmasks provided by the network processor.
7. The method according to claim 4 , wherein the lookup engine retrieves a port bitmask for a next received packet only after receiving said third indication.
8. The method according to claim 4 wherein said third indication is said modified bitmask.
9. The method according to claim 4 wherein said third indication is sent based on a value of a replication pointer.
10. A network switch comprising:
a look-up engine operative to retrieve a port bitmask in response to a header portion of a received packet and to forward the received packet only in response to receiving a modified port bitmask and a release signal corresponding to said received packet, wherein the port bitmask comprises a plurality of bits that correspond to respective ports in the network switch and wherein the states of the plurality of bits indicate whether the respective ports are to receive a copy of the received packet;
a network processor operable to perform a processing function, in response to at least one of said received packet and said port bitmask, to generate the modified port bitmask, to provide said release signal corresponding to said received packet and to provide the modified port bitmask to the lookup engine.
11. The network switch according to claim 10 wherein each of said lookup engine and said network processor receive a first indication that the packet has been received.
12. The network switch according to claim 10 wherein said look-up engine provides for said network processor a second indication, said second indication indicating that said port bitmask has been obtained.
13. The network switch according to claim 10 wherein said network processor is operative, in response to said first indication, to execute said processing function and to provide to said look-up engine a third indication, said third indication indicating that said processing function has been executed.
14. The network switch according to claim 10 wherein said network processor performs the processing function in parallel with the retrieving by the lookup engine.
15. The network switch according to claim 13 wherein the lookup engine forwards a plurality of copies of the received packet, each of the plurality of copies in response to one of a plurality of modified port bitmasks provided by the network processor.
16. The network switch according to claim 13 , wherein the lookup engine retrieve a port bitmask for a next received packet only after receiving said third indication.
17. The network switch according to claim 13 wherein said third indication is said modified bitmask.
18. The network switch according to claim 15 wherein said third indication is sent based on a value of a replication pointer.