CARRIER NETWORK OF VIRTUAL NETWORK SYSTEM, AND COMMUNICATION NODE OF THE CARRIER NETWORK

摘要

A control frame communication method and a carrier network in which a spanning tree causing no loops can be built even in a dual homing structure. The same virtual network identifier is assigned to a plurality of user networks connected to a carrier network, thereby building a virtual network. An entrance communication node connected to a first user network adds a tag including the virtual network identifier to a control frame transmitted from the first user network, and transmits the control frame to which the tag has been added to a destination decided based on the virtual network identifier. An entrance communication node connected to a second user network removes the tag from the control frame and transmits it to the second user network.