A failure detection method for integrated voice/data packet networks

A failure detection strategy at the data-link layer, implementable between frame-relay network nodes, is described for integrated voice/data packet networks. This strategy makes it possible to respond to link failures early enough to maintain data-session continuity. A simple, two-phase approach is proposed. In the first phase, the presence of a bit error rate violation along the packet link during short, fixed-length time segments is determined. In the second phase, the failure decision is made on the basis of a sequential algorithm. A simple table lookup implementation of the algorithm that requires no real-time computation is described