A modular design for providing ISDN switching hardware in the GTD-5 EAX

Innovative hardware and firmware design approaches for switching network and facility interface circuitry are described. The ISDN module makes use of recent advances in semiconductor and packaging technology. These technologies are supplemented by novel design techniques which provide a highly integrated, fault-tolerant and modular system. The module supports basic (2B+D) and primary (23B+D) rate subscriber access to the ISDN. Basic rate access is provided at the S reference point according to CCITT recommendations, and at the U reference point via a proprietary interface. This implementation provides both circuit and packet switching capabilities and allows for evolution toward future wideband services