United States Patent  [li] Patent Number: 5,317,566
Joshi  Date of Patent: May 31, 1994
A distributed digital communications network has an originating node and a multiplicity of destination nodes. The various nodes are interconnected by links and at least some of the nodes are accessible to other nodes only by multiple links. To save time in establishing the least cost path from an originating node to a destination node, the attributes of the various links are stored in memory at the originating node, a least cost path from the originating node to a destination node is calculated in response to a connection request and stored in memory. Then, when a subsequent connection request to any destination node requires the same link attributes as the least cost path already stored in memory, that same least cost path is used if it is still operational. Significant time saving is achieved in that no new least cost calculation need be made.
14 Claims, 7 Drawing Sheets