Patent ID: 6590864
Filing Date: 2003-07-08
Classification: H04J

Abstract:
A network node connected to a remote network node by an active transmission system and a standby transmission system, comprising:active receive circuitry for receiving communication signals from the active transmission system and detecting an operating state of the active transmission system; active transmit circuitry for transmitting communication signals over the active transmission system to said remote network node; standby receive circuitry for receiving, from the standby transmission system, a status signal indicating an operating state of said active transmission system detected by said remote network node from said transmitted communication signals; standby transmit circuitry for transmitting a status signal indicating the operating state detected by the active receive circuitry over the standby transmission system to said remote network node; and control circuitry responsive to an operating state detected by said active receive circuitry and an operating state indicated by the status signal of said standby receive circuitry for performing a protection switching between said active and standby transmission systems.