Patent ID: 6304547
Filing Date: 2001-10-16
Classification: H04L

Abstract:
A communications network system including a plurality of unit networks wherein a plurality of communication devices, which respectively accommodate a single or plurality of local communication terminals, are connected through a single communication path to communicate among the respective local communication terminals through the communication path via corresponding communication devices, the communication path being set in each of the unit networks leaving a band to be used for an alternate communication path to respectively carry out the communications, characterized in that the communications network system comprises:internetwork connection circuits provided among the unit networks;trouble detecting means for detecting a trouble occurred in the respective unit networks; andalternate communication path forming means which, when a trouble is detected by the trouble detecting means, connects a communication path of a first unit network having the trouble to a communication path in a non-used band of a second unit network which is adjacent thereto through the internetwork connection circuits to form the alternate communication path bridging from the first unit network to the second unit network through the internetwork connection circuits between two communication devices adjacent to a troubled spot within the first unit network.