United States Patent  [li] Patent Number: 5,142,531
Kirby  Date of Patent: Aug. 25,1992
A network is arranged to generate circuits between source node (N5) and destination nodes (No) by means of datagrams which are guided at each node over a path (D) which minimizes delay in establishing the circuit. Certain sub-destination nodes (Ne and Nc) are designated as intermediate circuit nodes by the datagram and accordingly a circuit (C) is established. Each circuit node is determined by the preceding circuit node in such a manner as to minimize the hop count to the destination node (No). To this end, each node incorporates in its memory (M) a first list (LIST 1) showing the link with the best hop count to each possible destination node and also incorporates a list (LIST 2) of its links with the best transmission delay to the destination node. These lists are updated dynamically by means of routing information packets which are exchanged between neighboring nodes. However, best hop count and best delay information is not transmitted over those links (L) which are themselves the subject of that information. In this manner "ping-pong" type looping is avoided.
27 Claims, 6 Drawing Sheets