Method of caching routes in asynchronous transfer mode PNNI networks

摘要

A caching method to greatly reduce the time to calculate routes based on the well known Dijkstra routing algorithm. A first embodiment is suitable for use in applications where only a single class of call is in use. A second embodiment is suitable for use where multiple classes of calls are is simultaneous use. A sequential number field and a global variable holding a sequential count are maintained by each node. When a node is put on the PATH list, the global sequential count variable is copied to the sequential number field for that particular node descriptor. Subsequently, when a route to destination node is to be calculated, for each node marked as a destination, the global sequential count variable and the node descriptor sequential number field are checked if they are equal. If they are, it means that a route has already been calculated to the destination which was already determined to be optimum.