Dynamic K-Shortest Path (DKSP) facility restoration algorithm

This paper describes the dynamic K-shortest path (DKSP) algorithm for distributed facility restoration and its performance in a simulation of AT&T's high-capacity digital facilities network. The guiding paradigm of this algorithm is that of a switched network. At each facility node in the network, a local controller (LC) directs the activities of a digital cross-connect system (DCS) to route high-capacity digital connections around failures. The LCs communicate with each other via a connectionless network using routers and signaling links embedded in the transmission systems between nodes. After a failure, the LCs disseminate information about failed transmission links to the whole network. High-capacity digital connections are then restored by a call-control protocol. The simulation shows that the algorithm's efficiency is close to that of a centralized algorithm, and that its rate of finding alternate routes in this large network is approximately 50 ms per restoration path.