Patent ID: 8553568

Claim:
A method of processing defect conditions in a maintenance endpoint (MEP) of a first domain, the MEP a component of a bidirectional forwarding detection (BFD) to Y.1731 interworking interface (IWF) in a multi-protocol label switching (MPLS) network, the method comprising: receiving a peer alarm indication signal (AIS) at an IWF MEP of a BFD domain of the MPLS network from an IWF MEP in a second domain of the MPLS network, wherein the IWF MEP of the BFD domain operates according to a state machine; in response to receiving the peer AIS from the IWF MEP of the second domain of the MPLS network, the IWF MEP of the BFD domain of the MPLS network transitioning the state machine to a down/off state; halting BFD protocol data unit generation, periodically providing an AIS indication in a format appropriate for the BFD domain to a remote MEP in the BFD domain of the MPLS network; and ignoring other messages received at the IWF MEP of the BFD domain until it is no longer receiving a peer AIS from the IWF MEP of the second domain; and wherein other states of the state machine include, an init state wherein a remote MEP in the BFD domain is communicating with the BFD IWF MEP but a session has not yet been established between the remote MEP in the BFD domain and the BFD IWF MEP; an up state wherein a BFD session has successfully been established between the remote MEP in the BFD domain and the BFD IWF MEP; a down state wherein a BFD session between the remote MEP in the BFD domain and the BFD IWF MEP is down and a forwarding path from the BFD IWF MEP is unavailable.