Trunk network system for multipoint-to-multipoint relay

A node device for constituting a trunk network that connects together external devices, said node devise comprising:

• external connection ports for connecting with said external devices;
• a port state monitor unit for classifying said external connection ports into groups in advance, storing the correspondence of said external connection ports and said groups, and detecting changes in the states of said external connection ports;
• and
• a group state management unit for, upon the detection in said port state monitor unit of a change in the state of any external connection port, reporting to other nodes that make up said trunk network state information that includes the states of groups to which the external connection port corresponds;
• and upon receiving state information from any other node and in accordance with the states of said groups that are included in the state information, changing the states of external connection ports that belong to these groups.

A trunk network system of a configuration having a plurality of nodes in which said plurality of nodes are connected together, wherein:

• external connection ports of said plurality of nodes are classified in groups in advance, and the correspondence of said external connection ports and said groups is set in said nodes;
• upon detection of a change in the state of a said external connection port in any node, state information that includes the states of the groups to which the external connection port belongs is transmitted from the node to other nodes that make up said trunk network;
• and
• in said other nodes that have received said state information, the states of external connection ports that belong to the groups are forcibly changed in accordance with the states of said groups that are included in the state information.