IP Packet Forwarding Method and Apparatus for ATM Switch-based IP Router, And Routing System using them

摘要

PURPOSE: A high-speed IP(Internet Protocol) packet forwarding device and method for a switching system based on ATM(Asynchronous Transfer Mode) and a routing device using the same are provided to use a fixed length of switching function, and to process an IP forwarding function to be distributed, so that traffic bottleneck phenomenon can be reduced and a switching function can be improved. CONSTITUTION: An IP(Internet Protocol) packet from external is received, to search an exact matching table and an LPM(Longest Prefix Matching) table is searched using a destination header of the received IP packet, to confirm whether exact matching is successful. If successful, the search of the LPM matching table is suspended, and forwarding information is obtained using a destination address stored in the exact matching table. The received IP packet is delivered to the destination address. If the exact matching is failed, the search of the LPM matching table is maintained to complete LPM matching check. Forwarding information is obtained using the destination address stored in the LPM matching table. The received IP packet is delivered to the destination address. A result of the LPM matching is registered in the exact matching table.