High speed header translation processing

Computer network apparatus having a plurality of input ports and a plurality of output ports and operable to convert a received frame having a received frame header to a transmit frame having a transmit frame header prior to transmission of said frame, said apparatus comprising;

• a first controller operable to parse said received frame header to derive a received destination address from said header and to identify the protocol of said received frame;
• cache apparatus comprising a cache controller and a cache memory, said first controller operable to forward said received destination address to said cache apparatus;
• said cache apparatus operable in response to reception of said received destination address from said first controller:
• to compare said received destination address to information stored within said cache memory to provide an indication of whether a match or no match exists between said destination address and said information stored within said cache memory;
• to identify selected ones of said plurality of output ports for transmission of said frame and a transmit destination address, in the event said comparison yield a match between said received destination address and said information stored within said cache memory;
• to generate an indication of said no match condition, in the event said comparison yields to match between said received destination address and said information stored within said cache memory;
• a second controller;
• said cache apparatus operable:
• to forward to said second controller information comprising said identification of at least one of said plurality of output ports for transmission of said frame and an indication of said match, in the event said comparison yielded said match;
• and
• to forward to said second controller information comprising said indication of no match in the event said comparison yielded the indication that no match exists;
• said second controller, at least some of the time, operative in response to said information received from said cache apparatus to select further processing of said frame via a first frame forwarding path in the event of a no match condition and a second path which comprises a higher speed frame forwarding path than said first frame forwarding path in the event of said match condition;
• said first frame forwarding path including a third controller operative to process said frame in software;
• said second path including a fourth controller operative to translate said received frame header to said transmit frame header prior to transmission of said frame from said at least one of said plurality of output ports.