Communications failure recovery in data packet networks based on fast determination of alternate routes

摘要

Data communications system for handling IP packets have a route evaluation mechanism for determining a least cost route for delivery a packet to a destination, and an alternate route evaluation mechanism for evaluating possible routes for packet delivery having cost different from the cost of the least cost route. In response to evaluation performed by the alternate route evaluation mechanism, an alternate route table generator produces an alternate route table containing alternate routes for delivery of the packet to the destination. A fast failure recovery algorithm is carried out to determine entries in the alternate route table.