Method for operating and apparatus for a back-plane supporting redundant circuit cards

摘要

The present invention provides clear and robust arbitration of which of two system controllers is in control of a telecommunications switching system. Each system controller monitors and actively reports its status to a separate arbitration circuit. The resultant signal from the arbitration circuit tells the system which controller to obey. By feedback of its own output unnecessary switching or ill-defined control states are avoided. In particular, if either both or neither system controllers is reporting itself as OK, the system does not switch controllers. In addition, the arbitration circuit is fed redundant clock signals and support, making it effectively redundant.