Bandwidth Management of Multiple LSP Against Link Failures using WMMF

Local Restoration has always been a main concern in MPLS networks. The main task of the Multi Protocol Label Switching (MPLS) recovery mechanism lies in controlling the traffic flow in the network and finding a backup path such that failed links or nodes can be bypassed locally from the first node that is upstream from the failures. The bandwidth reserved on each link along the backup paths are expensive and can be shared by all the service LSPs provided the protected failure points are not expected to fail simultaneously. This paper examines the traffic engineering problem of flow routing and fair bandwidth allocation where flows can be split to multiple paths. The contribution of this paper is an algorithm for per commodity weighted max-min fair rate vector. The algorithm is a fully polynomial epsilon- approximation (FPTAS) algorithm and is based on a primal-dual alternation technique. The approximation algorithm maximizes throughput when the routed traffic is required to be locally restorable. Index Terms Local restoration, MPLS, backup path, routing, traffic engineering.