Network switch with mutually coupled look-up engine and network processor

Abstract

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 - 10 . (canceled) 
     
     
         11 . A network switch comprising:
 a look-up engine to retrieve search results in response to a header portion of a received packet and to forward the received packet only in response to receiving modified search results and a release signal corresponding to said received packet; and   a network processor to perform a processing function, in response to at least one of said received packet and said search results, to generate said modified search results, to provide said release signal corresponding to said received packet and to iteratively provide modified search results to the lookup engine.   
     
     
         12 . The network switch according to  claim 11 , wherein each of said lookup engine and said network processor is to receive a first indication that the packet has been received. 
     
     
         13 . The network switch according to  claim 11 , wherein said look-up engine is to provide for said network processor a second indication, said second indication indicating that said search results have been retrieved. 
     
     
         14 . The network switch according to  claim 11 , wherein said network processor is, 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. 
     
     
         15 . The network switch according to  claim 11 , wherein said network processor is to perform the processing function in parallel with the retrieval of the search results by the lookup engine. 
     
     
         16 . The network switch according to  claim 14 , wherein the lookup engine is to forward each of a plurality of copies of the received packet in response to one of a plurality of modified search results being provided by the network processor. 
     
     
         17 . The network switch according to  claim 14 , wherein the lookup engine is to retrieve search results for a next received packet only after receiving said third indication. 
     
     
         18 . The network switch according to  claim 14 , wherein said third indication is said modified search results. 
     
     
         19 . The network switch according to  claim 16 , wherein said third indication is to be sent based on a value of a replication pointer. 
     
     
         20 . The network switch according to  claim 11 , wherein the search results comprise a port bitmask. 
     
     
         21 . 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, search results in response to receipt of a header portion of a received packet;   executing, at a network processor, a processing function in response to at least one of said received packet and retrieval of said search results, said processing function comprising:
 generating modified search results of the retrieved search results; 
 providing a release signal corresponding to said received packet; and 
 providing the modified search results to the lookup engine; and 
   forwarding the received packet only in response to receiving, at the look-up engine, the modified search results and a release signal corresponding to said received packet.   
     
     
         22 . The method according to  claim 21 , further comprising:
 receiving, in each of said lookup engine and said network processor, a first indication that the packet has been received.   
     
     
         23 . The method according to  claim 22 , further comprising:
 providing, by the look-up engine, for said network processor a second indication, said second indication indicating that said search results have been obtained.   
     
     
         24 . The method according to  claim 23 , further comprising:
 in response to said first indication, executing, by said network processor, said processing function and providing to said look-up engine a third indication, said third indication indicating that said processing function has been executed.   
     
     
         25 . The method according to  claim 21 , wherein executing the processing function further comprises executing, by said network processor, the processing function in parallel with the retrieving by the lookup engine. 
     
     
         26 . The method according to  claim 21 , further comprising:
 forwarding, by the lookup engine, a plurality of copies of the received packet in response to receipt of one of a plurality of modified search results provided by the network processor.   
     
     
         27 . The method according to  claim 24 , wherein retrieving the search results further comprises receiving, by the lookup engine, next search results for a next received packet only after receiving said third indication. 
     
     
         28 . The method according to  claim 24 , wherein said third indication is said modified search results. 
     
     
         29 . The method according to  claim 24 , wherein providing the third indication further comprises providing the third indication based on a value of a replication pointer.