Adaptive segment path restoration (ASPR) in MPLS networks

Two important factors must be considered when selecting a restoration scheme in MPLS networks. Firstly, the restoration time, and consequentially the packet latency of the restored trafiic, has to satisfy the requirements of realtime services. Secondly, the spare capacity requirement should be costeffective. This paper proposes a novel proactive restoration scheme that is both fast-acting and resource efficient, called Adaptive Segment Path Restoration (ASPR). The basic idea is to divide a LSP into several segments according to the network topology. For each segment of the primary path, a backup path is provided. A comparative study of ASPR is provided which shows that of the schemes considered, ASPR has the shortest overall restoration length and smallest backup LSP hop count, whilst remaining better than most other restoration schemes in terms of its resource requirements.