Patent ID: 6421342
Filing Date: 2002-07-16
Classification: H04L

Abstract:
A method of forwarding a packet of data across a switching node on a network, said packet of data including a destination address identifying a destination node on the network toward which the packet of data is to be forwarded along an output path out of the switching node, the destination address being dividable into a plurality of subaddress fields holding a respective plurality of subaddresses, said method comprising:storing in a memory a table that associates each of a plurality of destination addresses with an output path out of the switching node over which a packet can be forwarded toward the destination node identified by the destination address, each of a plurality of portions of the table being associated with a respective subaddress field and being accessible by use of the subaddress held by the associated subaddress field; providing a series of subaddress processors, each of the subaddress processors being associated with a respective subaddress field and receiving the subaddress held by its associated respective subaddress field and using the subaddress to access the portion of the table associated with the subaddress field to receive information related to the output path associated with the destination address; receiving a series of destination addresses from a respective series of packets of data to be forwarded across the switching node; using the series of subaddress processors to access the table in a pipelined fashion to retrieve an output path for each of the received packets of data, such that: during a first addressing interval, a first subaddress processor, associated with a first subaddress field, uses the subaddress held by the first subaddress field of a first received destination address to access a first portion of the table associated with the first subaddress field; and, during a second addressing interval, (i) a second subaddress processor, associated with a second subaddress field, uses the subaddress held by the second subaddress field of the first destination address to access a second portion of the table associated with the second subaddress field, and (ii) the first subaddress processor uses the subaddress held by the first subaddress field of a second received destination address to access the first portion of the table associated with the first subaddress field.