An application of reliability theory to a telephone network

This paper describes an implementation of a method of calculating the availability, mean time to repair and mean time to failure of signalling relationships in a telephone network. The method is based on recognising that the failure states of a signalling relationship and their probabilities can be enumerated by using a branch and bound technique. The method can (in principle) be applied to a network of any complexity or size and allows arbitrary restriction on the use of certain elements to be imposed. The algorithm has been implemented in the ‘C’ language. Practical difficulties arising when the theory is applied to practical problems are discussed.