A restoration methodology based on pre-planned source routing in ATM networks

This paper describes a restoration methodology for ATM networks that is built on top of a pre-planned source routing system in the network and operates on a connection-by-connection basis. Unlike most of the existing proposals that use dedicated spare facilities to protect network traffic against network fault conditions, this scheme simply takes advantage of unused network capacity to redirect traffic from the problem area. This restoration methodology requires the upstream neighboring switches to send messages back to the corresponding sources of the affected connections to find an alternative route. Given that this capability is being incorporated for new call setup in the signalling protocol for private ATM networks by the ATM Forum, the additional development cost and operations overhead associated with this restoration methodology is relatively insignificant. The performance of the proposed restoration methodology is discussed based on simulation studies for video on demand (VoD) applications.