CONGESTION CONTROL SYSTEM, CONGESTION CONTROL METHOD, CONGESTION CONTROL PROGRAM, AND PROGRAM RECORDING MEDIUM

摘要

In the present invention, a service network includes, when user terminals are divided by area, subscriber accommodation nodes that accommodate the user terminals present in the respective areas and relay nodes that perform relay of information among the subscriber accommodation nodes. The congestion control system further includes an edge router that routes a processing request for a communication service received from each of the user terminals to each of the subscriber accommodation nodes on the service network side as a control message and a congestion control server that controls congestion states of the subscriber accommodation nodes and the relay nodes. The subscriber accommodation node detects, when congestion occurs or it is likely that congestion occurs in the subscriber accommodation node because of a large number of control messages from the edge router, the occurrence of the congestion or the likelihood of occurrence of congestion and notifies the congestion control server to that effect. The congestion control server transmits a congestion control message for regulation to the edge router that routes the control message to the subscriber accommodation node, in which the congestion or the likelihood of occurrence of congestion has occurred, to thereby regulate an operation for routing the control message to the subscriber accommodation node, in which the congestion or the likelihood of occurrence of congestion has occurred, from the edge router.