A point to multipoint routing algorithm based on source routing

This paper proposes a routing path selection mechanism for source routing-based PtMP (point-to-multipoint) call in the ATM switching system. In particular, it suggests a PtMP routing path selection method that can share the maximum amount of resources prior to the optimal path selection, guaranteeing the reduction of path calculation time and cycle prevention. The purpose of this algorithm is to maximize the sharing of resources by finding the branch point closest to the destination node. Therefore, this algorithm using back-tracking chooses from among the nodes neighboring the destination node and fixes the node crossing first the node on the existing path having the same call ID as the branch node, thereby constructing the optimal PtMP routing path. The optimal node is selected by the use of Dijkstra algorithm. That is to say, the PtMP routing path selection performs the step of cross node selection and optimal node selection (optimal path calculation) among neighboring nodes by back-tracking. This technique reduces the process of searching for a routing information table for path selection and path calculation time, it also easily solves the cycle prevention during path establishment.