THE DEVELOPMENT OF BROAD-BAND SIGNALING PLATFORMS

Mao Zedong once said: ''All genuine knowledge originates in direct exp erience.'' This paper describes the experiences gained through a range of development projects, all concerned with the design, development, demonstration and maintenance of real broadband signalling systems. Th e authors have participated in the development of a variety of systems offering broadband capabilities, all of which support some form of br oadband signalling between the service user and the service provider. The process of designing and building such systems can provide invalua ble insights into issues such as development methods, signalling perfo rmance, programming interface definitions, etc, none of which are appa rent from purely paper-based studies or through the standards specific ation process. This 'coal-face' experience covers both collaborative a s well as internal BT projects, with each system being subject to a wi de variety of service requirements. In addition, the period of work co vered by the developments described in the paper encompasses broadband signalling systems that on the one hand predate the published ITU-T s tandards on broadband ISDN systems and opt the other include a compreh ensive testbed supporting an interworking set of broadband signalling interfaces based on the appropriate signalling standards defined by bo th the A TM Forum as well as the ITU-T.