Multiple backup VPs based self-healing protocol for ATM networks

The self-healing network is particularly interesting with regard to asynchronous transfer mode (ATM) networks, because the restoration time can be shortened by using the features of ATM networks that permits one to establish backup virtual paths (VPs) with zero bandwidth. This paper studies a new protocol that allows more than one backup VPs to protect single working VP. The number of backup VPs used may be a function of the normal VP´s hop length. Results show that this improves considerably the restoration speed of ATM networks from a failure. Two sorts of techniques, named non-overlapped and overlapped backup VPs, are presented. The non-overlapped backup VP based self-healing protocol can recover from all single-link and most node failure scenarios while the overlapped backup VP based algorithm can recover from all link/node failure scenarios. Operation of the protocol is described and the performances are evaluated in term of two criteria, namely the restoration ratio and amount of additional transmission capacity to be employed. Two different meshed network topologies are used to perform the comparative analysis between the new protocol and a better-known end-to-end one