US Patent 7340163 Signaling protocol and architecture for protection rings

Transparent network elements (10) pass data in a data communication plane (24) over optical links (42) and pass control information in a control communication plane (22) over a out-of-fiber/out-of-band (OF/OB) network (44), such as an IP-based network. Previously developed protection state machines (38), such as those used in traditional SONET/SDH systems can be used along with new protection state machines (38), such as shared ring protection state machines. Client State machines (40) and a signaling controller (30) interface between the protection state machines (38) and the OF/OB network (44) such that the protection state machines (38) are isolated from the technicalities of transmission in the separate network.