Experiences of developing, deploying and operating an automatically switched digital service protection network

The major requirement for the British Telecom ASDSPN system is to improve the availability of 140 Mbit/s digital transmission paths over and above that which is possible using manual procedures. The authors report on the final design and implementation of a first generation system for automatic network protection, recording departures from the original concept and discuss how the experience gained applies, in general terms, to network management. It will be appreciated that the operational experiences, gained on BT´s DTN, will apply to future networks such as the synchronous digital hierarchy (SDH)