Patent ID: 7898942
Filing Date: 2011-03-01
Classification: H04L

Abstract:
1. A ring network system with a first ring network and a second ring network connected by a living communication path and a spare communication path, wherein each node in said first ring network and in said second ring network comprises a learning data base for storing a correspondence relationship between an address of a terminal outside the ring network and an address of a node within the ring network, a failure occurrence determination unit for determining that a failure occurs on the living communication path, and an erasure unit for forcibly erasing information stored by the learning data base without waiting for a lapse of an aging time when said failure occurrence determination unit determines that a failure occurs on the living communication path, each node other than a contact node arranged as an end portion of the living communication path and the spare communication path comprises a broadcast unit for, when an address of a node corresponding to a transmission destination address that a user frame received from a terminal outside the ring network fails to be stored in said learning data base, broadcast-transmitting a frame including said user frame accommodated as a payload and an address of the node itself, an abandoning unit for, when receiving a broadcast-transmitted frame including the address of the node itself, abandoning said broadcast-transmitted frame, a contact node arranged as an end portion of the spare communication path comprises a state change unit for changing a port connected to the spare communication path to a state of enabling a user frame to be sent out when said failure occurrence determination unit determines that a failure occurs on the living communication path, and a converting unit for converting said broadcast-transmitted frame into said user frame, and sending said user frame to said first ring network or said second ring network through said spare communication path.