Information systems for very large applications present problems of scale which generate the need for particular software design techniques. The system used by BT for its customer services is usable as a paradigm for any user operating with a large and complex client base. This book will cover some of the more important systems currently deployed by BT to manage its multi-million customer network, the architecture that guides these systems, the evolving technology from which they are built and the future directions in their evolution. Computing Systems for Global Telecommunications is essential reading for software engineers working on all types of large Operational Support Systems; systems designers working for telecommunications providers; advanced undergraduate and postgraduate students and researchers studying software engineering.