A predictive alternate path routing scheme supporting the best QOS in ATM networks

In routing protocols currently being specified for use in ATM networks, connection setup messages will be forwarded using source routing based upon multi-level hierarchy of addressing, and using alternate routing based upon progressive control against call blocking. But the existing progressive control do not guarantee the optimal QOS in the data transfer phase since selecting an alternate path can not be optimal. We show that, if the source node submits information about optimal paths in the connection setup message, even intermediate nodes can choose an optimal path from the entire network point of view. For this purpose, we propose a new method that finds out n-1 crankback destination nodes when there are n alternate paths to each destination. We also prove that the new method presented offers better performance than the existing one