Scheme for interlocking line card to an address recognition engine to support plurality of routing and bridging protocols by using network information look-up database

摘要

The present invention provides an interlock scheme for use between a line card and an address recognition apparatus. The interlock scheme reduces the total number of read/write operations over a backplane bus coupling the line card to the address recognition apparatus required to complete a request/response transfer. Thus, the line card and address recognition apparatus are able to perform a large amount of request/response transfers with a high level of system efficiency. Generally, the interlocking scheme according to the present invention merges each ownership information storage location into the location of the request/response memory utilized to store the corresponding request/response pair to reduce data transfer traffic over the backplane bus. According to another feature of the interlock scheme of the present invention, each of the line card and the address recognition engine includes a table for storing information relating to a plurality of database specifiers. Each of the database specifiers contains control information for the traversal of a lookup database used by the address recognition apparatus. At the time the processor of a line card generates a request for the address recognition apparatus, it will analyze the protocol type information contained in the header of a data packet. The processor will utilize the protocol type information as a look-up index to its table of database specifiers for selection of one of the database specifiers. The processor will then insert an identification of the selected database specifier into the request with the network address extracted from the data packet.