Patent ID: 8089936

Claim:
A communication system including a first node and a second node configured to communicate with the first node, the system comprising: a first unit that transmits a signal of a second protocol belonging to a second layer, the signal including a source node identifier, to a first logical communication link established between the first node and the second node by using a first protocol belonging to a first layer, the second layer being higher than the first layer; and a second unit that manages the first logical communication link in association with the source node identifier added to the signal received through the first logical communication link, wherein the second unit comprises: an identifying unit to identify, based on the source node identifier associated with the first logical communication link, a second logical communication link that is associated with the source node identifier and has been established between the first node and the second node before the node identifier added to the signal is managed in association with the first logical communication link; and a releasing unit to release either one of the first and second logical communication links.