Forwarding information retrieval technique

摘要

An improved method for retrieving next forwarding destination of a received data signal is disclosed. First, a plurality of first tables and a second table are stored in the retrieval table. The first tables are hierarchically arranged according to division of the destination address, an entry of each of the first tables including a second-table pointer indicating a next accessed second entry of the second table. The second table serves as an index table of the first tables. Each of entries of the second table includes a hop pointer and a first-table pointer indicating a next accessed first table. The second table and a selected one of the first tables are alternately accessed depending on a first-table pointer included in an accessed entry of the second table while retrieving an entry of an accessed first table using a corresponding divisional portion of the destination address. A hop pointer is read from a finally accessed entry of the second table as a retrieval result.