A research testbed for switching software studies

We describe the architecture of a simulation testbed for control software of public network switching systems. The testbed contains simulations of customer premises equipment and of the switching system in a central office. The testbed focuses on the control aspects: a realistic handling of the signalling protocols between subscribers and the network, and the call processing in the switch. The information transfer (data, voice etc.) is simulated only to show its presence without expectation of realistic performance. The testbed architecture components are: the customer premises equipment; subscriber/switch interface “line cards”; a switching fabric (matrix); and the switch control system. The implementation is designed to operate on a distributed system, e.g. a set of computers connected on a local area network. The objective of this system is the study of and experimentation with control software architectures in the switch. We have built a first implementation which simulates an ISDN switching system, and we report on the design decisions of the basic architecture