Method of derermining an optimal end node to end node route through a data communications network

When computing a least weight path from an origin node to a destination node in a data communication network, a route-computing network node uses information provided by the origin and destination nodes to compute least weight routes from those nodes to adjacent network nodes. The route-computing network node uses information in the topology database to compute least weight routes from network nodes adjacent the origin node to network nodes adjacent the destination node. The results of the compu­tations are combinated to determine an optimum route from the origin node to the destination node. The topology database need not include information about the transmis­sion groups connecting the origin/destination nodes to network nodes.