3com Corporation

Hewlett-packard Development Company, L.p.

3com Technologies

Sorcha O'Callaghan

Kevin Jennings

Eugene O'Neill

Edele O'Malley

Kevin Loughran

Neil O Fanning

Joseph N Butler

Con David Cremin

Richard A Gahan

Raymond Beechinor

David Nolan

Christopher Gilbert

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.

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

A communication device which includes a hardware trie search facility. At least part of a memory is divided into memory blocks, each of said blocks consisting of a multiplicity of locations, at least some of said locations each providing when accessed a pointer to another block and an indication of the size of the block. A shift register holds an address key, and a trie block is accessed using an address composed of a number of bits related to said indication of the size of the block. The key is shifted by said number of bits prior to a subsequent stage of the search. Part of the memory comprises an associated data table which includes entries of data enabling a packet to be forwarded and at least some locations in said blocks provide when accessed a pointer to an entry in the associated data table.

Communication device with forwarding database having a trie search facility

A method for distributing addressed data packets from an input channel to a multiplicity of packet queues includes receiving said addressed data packets and, responsive to first hashed addresses, distributing the addressed data packets to said queues in accordance with said first hashed addresses. A first hash function is applied to selected address data of each of said addressed data packets to produce said first hashed addresses. At the same time a succession of different hash functions is applied to said selected address data in each of the packets to produce second hashed addresses and occurrences of each of the second hashed addresses are counted so as to obtain for each of said different hash functions a respective one of a plurality of set of counts, each such set representing the distribution of said packets that would occur in said queues if the respective one of the different hash functions had been applied to said addressed data packets. The sets of counts are analyzed to determined which one of them represents a best distribution of said packets and the hash function associated with the best distribution is applied to incoming packets in place of the said first hash function.

System and method for dynamically mapping a high speed link to a multiplicity of low speed trunked links

A network switch including a multiplicity of ports for the reception and forwarding of addressed data packets including network destination data and network source address data, and a forwarding database having a trie search facility organised in blocks of pointers, which are accessed by respective segments of a search key and identify in a last stage of a search forwarding data identifying each port from which a packet should be forwarded and in any stage of the search prior to the last stage a block of pointers, the switch including a device operable before the trie search facility is utilised for a given packet to compare a network destination address of the given packet with at least one stored address and when the network destination address matches the stored address to access the network source address data of the given packet for use as the search key.

Network switch with truncated trie look-up facility

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Dublin, Ireland

Sorcha O'Callaghan