Bridge communication system

A bridge communication system for connecting a plurality of bridge apparatuses, each connected to a local area network, through a backbone network and for performing communication, between terminals connected to the local area network connected to each bridge apparatus, through said backbone network, each bridge apparatus comprising:

• a backbone-network node address setting means for previously setting an address of a local node of said backbone network connected to said bridge apparatus;
• a learning table for storing at least a port number of said bridge apparatus and an address of a corresponding node of said backbone network, corresponding to respective terminals;
• means for sequentially registering in said learning table a source address designating a source terminal of a data frame received by said bridge apparatus via a port from one of said local area net work and said backbone network, a port number of the port receiving the data frame for said bridge apparatus, and a source backbone-network node address when the data frame is transmitted from said backbone network, said source address, said port number and said source backbone-network node address representing, respectively, an address of a terminal, a port number and an address of a node;
• and
• means for adding at least the address of the local node stored by said backbone node address setting means and the address of any node, obtained by searching said learning table, to said data frame to be transmitted to said backbone network as the source node address and the destination node address, respectively.