Patent ID: 7379454

Claim:
A packet routing apparatus comprising: a plurality of input line interfaces connected to input lines, respectively; a plurality of output line interfaces connected to output lines, respectively; and at least one routing processor for specifying a transfer destination of an input variable length packet by referring to a routing information table based on header information of the input packet, wherein said routing information table is comprised of a plurality of sub-tables, each of the sub-tables including at least one first type entry indicative of routing information and at least one second type entry for designating another said sub-table to be referred to, said routing processor refers to one said sub-table determined according to the input line interface and, when the second type entry is retrieved as a table entry having a relation corresponding to the input packet, refers to the another sub-table designated by the second type entry to thereby specify the transfer destination of said input packet, said packet routing apparatus routes the input packet received by any of said input line interfaces to an output line interface specified by said routing processor, each of said input line interfaces has an adding unit for adding sub-table designation information to the packet received from the input line, and said routing processor specifies a sub-table to be referred to on the basis of sub-table designation information extracted from each input packet.