PROTOCOL TESTER FOR MESSAGE BASED SIGNALLING SYSTEMS.

Under British Telecom's competitive purchasing policy, exchange equipment is being procured from a number of different suppliers. Although this equipment is purchased to a common 'black box' specification, to ensure consistent interworking between exchange systems, full interface conformance and system performance must be tested at product acceptance against an independent standard. In the case of equipment to support BT's ISDN service suppliers are implementing to BTNR's 190 and 191 for DASS 2 and 1420. To ensure an independent standard for validating suppliers' equipment BT is developing the Digital Communications Tester (DCT). Initially intended for assessment of ISDN signaling systems protocols, the tester architecture and high level test language are readily extendable to assessing other protocols, such as CCITT No 7, X25, X75 and X400.