The design of a topology information maintenance scheme for a distributed computer network

In order for the nodes of a distributed computer network to communicate, each node must have information about the network's topology. Since nodes and links sometimes crash, a scheme is needed to update this information. One of the major constraints on such a scheme is that it may not involve a central controller. In this report a straightforward scheme involving adjacency matrices and a broadcast scheme are discussed and their inadequacies described. The NETCHANGE Protocol which is based on Baran's “Hot Potato Heuristic Routing Doctrine,” is presented. This system has been implemented on the MERIT Computer Network and its correctness has been proved. We end by showing how the NETCHANGE Protocol can be modified into a shortest path algorithm.