Topology based path computation for provisioning in transport networks

Service providers employ different transport technologies like PDH, SDH/SONET, WDM/DWDM, ATM, DSL etc. to support different types of traffic and service requirements. Dynamic service provisioning requires the use of on-line algorithms which automatically compute the path to be taken to satisfy the given service request. Transport networks are deployed such that they follow different topologies such as linear, ring, mesh, protected linear, dual homing etc. In this work, a new mechanism for path computation is proposed. Here, two types of graphs are considered: a super graph containing the topologies as nodes and common nodes as edges and the base graph containing network elements as nodes and physical links as edges. An algorithm to compute the best path taking into account the topologies present in the super graph and then finding the basic path from the topology path is proposed. It takes into account topologies with and without protection and protection path is found wherever required. When every edge in the network belongs to a topology, then the performance of the proposed algorithms is much better when compared with the traditional path computation algorithms. But, when many of the edges do not belong to any topology in the network, then the performance of the algorithms were poor when compared with the traditional path computation algorithms.