Patent ID: 7092361

Claim:
A method of notifying a first ATM communication network of a fault related to a label switch path (LSP) of a second MPLS communication network, said first ATM communication network connected to a third ATM communication network through said LSP of said second MPLS communication network, said first ATM communication network having a first ATM OAM protocol adapted to monitor integrity of said first ATM communication network, said second MPLS communication network having a second MPLS OAM protocol adapted to monitor integrity of said second MPLS communication network, said method comprising: detecting said fault related to said LSP of said second MPLS communication network by monitoring connectivity verification (CV), forward defect indicator (FDI), and backward defect indicator (BDI) packets of said second MPLS OAM protocol; generating a first OAM alarm indication signal (AIS) cell of said first ATM OAM protocol indicating detection of said fault; transmitting said first OAM AIS cell to said first ATM communication network to indicate said fault to said first ATM communication network thereby indicating a loss of communications with said third ATM communication network through said LSP.