A Comparative Study of Two Self Healing Protocols for ATM Networks

Abstract

ATM networks are high speed networks and the volume of information carried by them at any instant of time is enormous. Since this information is likely to be of high commercial value, the effect of a transmission link or node failure would be catastrophic. Therefore ATM networks need to be equipped with mechanisms by which the failure of a network entity can be detected and service restored by changing over to alternate entities. Restoration mechanisms based on the self healing concept have been successful in achieving restoration times well below the two seconds limit to prevent any interruption of service to the users. This paper studies two self healing protocols for ATM networks. One is the Backup Virtual Path Self Healing protocol, and the second is the Broadcast Self Healing protocol, which is an extension of the protocol proposed for STM networks. Simulation studies were carried out to compare their restoration speeds, spare resource requirements and maximum restoration ratio. The results suggest that the backup virtual path protocol has an edge over the broadcast protocol.