ATM network restoration using a multiple backup VPs based self-healing protocol

Physical route assignment and capacity allocation functions of a Virtual Path (VP) are decoupled in Asynchronous Transfer Mode (ATM) networks. This means a zero-bandwidth VP can be preconfigured as backup of a working VP. This feature makes self-healing ATM networks particularly interesting as faster and efficient restoration can be realized by capturing the necessary bandwidth on the backup VP after a failure. With an aim to further increase the restoration speed, we developed a new Multiple Backup VPs (MBV) based protocol that permits one or more backup VPs to protect a single working VP. This approach helps holding the spread of restoration information in reduced span leading to faster recovery. The multiple backup VPs can be setup either in overlapped or non-overlapped way. This paper describes the operation of the protocol and studies how it recovers from unidirectional and bidirectional single link failures using both non-overlapped and overlapped scenarios. Performances are evaluated in terms of restoration ratio for a meshed-topology.