British Telecommunications Plc has answered the critics who accused it of lagging behind the US and Germany in the introduction of ISDN services, with the announcement of its primary rate access service (CI No 1,039). Called Multi-line IDA, the new service will provide the 30 B+D data paths operating at 64Kbps at the line rental cost of UKP24.25 a quarter per channel, compared with UKP22.55 for an ordinary analogue business line, while the connection charge will depend on the availability of spare cable capacity at the customers’ premises and the local exchange. Where there is spare capacity, the connection charge is UKP1,000 for converting each group of 30 existing lines to digital transmission. The service will connect ISDN PABXs to System X exchanges using the DASS 2 signalling standard, with Telecom claiming that there are already some 18,000 Multi-line IDA ports operating at 2Mbps ready for use. British Telecom has also announced that IDA customers with terminal equipment that complies with the X21 interface standard will be able to access an international 64Kbps circuit-switched data service connecting them with users of France Telecom’s Transcom service for exchange of data and Group IV facsimile messages between common or compatible equipment.