Advances in Verifiable Fail-Safe Routing Procedures

Two new versions of a distributed protocol for establishing and maintaining loop-free routing tables for communication networks with changing topology are presented. The protocols here possess significant advantages over previous versions in -terms of complexity of the node algorithm and of the validation procedure, as well as the communication and storage needs. In addition, we present a procedure for establishing new and disrupted calls in a virtual or physical circuit-switched network, and for canceling existing calls, such that each call is loop-free and is established according to the routing tables provided by the protocol.