Survivability strategies for broadband networks

The survivability of telecommunications networks is of increasing importance as companies and individuals become more dependent on access to a range of communications services. The challenge for network operators is to design a cost-effective network to meet a range of survivability demands. This paper first examines the broad decisions involved in selecting a survivability strategy, such as which network layers should provide resilience and how to coordinate the actions of multiple layers. Methods for evaluating these strategies are described including optimisation methods to assist the network designer. Tools for simulating multi layer survivability and comparing the costs of alternative survivability mechanisms are described.