Patent ID: 7145882

Claim:
A method for providing automatic protection switching (APS) in a SONET/SDH network, the method comprising: receiving data at a network element on a first ring link, the data received on the first ring link comprising: a first plurality of bits designating one of a first plurality of protection switching nodes of a first ring as a source node for a first ring fault condition; a second plurality of bits designating one of said first plurality of protection switching nodes of said first ring as a destination node for said first ring fault condition; receiving data at the network element on a second ring link, the data received on the second ring link comprising: a third plurality of bits designating one of a second plurality of protection switching nodes of a second ring as a source node for a second ring fault condition; and a fourth plurality of bits designating one of said second plurality of protection switching nodes of said second ring as a destination node for said second ring fault condition; generating a SONET/SDH frame at the network element using the first, second, third, and fourth plurality of bits, wherein: (i) said first plurality of bits and said second plurality of bits are located within line overhead bytes of the SONET/SDH frame; and (ii) said third plurality of bits and said fourth plurality of bits occupy different locations in said line overhead bytes of said SONET/SDH frame than do said first plurality of bits and said second plurality of bits; transmitting the SONET/SDH frame from the network element on a third ring link.