BT´s ISDN service-availability, facilities and costs

British Telecom has two ISDN services: ISDN 30, which equates to primary rate access; and ISDN 2, which is CCITT basic rate access. A number of facilities are available for both, such as: calling line identity (CLI) which allows the receiver to identify the calling party; and network address extension (NAE) which allows sub-addressing on an ISDN line. The call tariffs are outlined, and the availability of services and equipment is discussed