Design of self-healing algorithm for ATM networks

Automatic and rapid network service restoration (self-healing) when failures occur is of increasing importance for network operations and management as network speed and bandwidth increase. In this paper, we study the self-healing problem of an ATM network at the virtual path (VP) configuration level. We analyze the design issues of self-healing algorithms, and develop a state transition and bandwidth division model of individual VPs and links. On top of the model, we design a restoration algorithm that searches and activates alternate VPs for the failed VPs by combining a preplan method and a double search method. The preplan method activates preassigned backup VPs dynamically, while the double search method searches for alternate VPs from both the source and destination nodes of failed VPs. The double search method is also applied to reconstruction of the backup VP plan. Simulations demonstrate that our new algorithms outperform existing preplanned and dynamic self-healing algorithms in both restoration time and restoration ratio.