iation T denoting Telecommunications and 1 for the first such committee. (CBEMA) is a trade association of manufacturers and suppliers of T1 has four interest categories: hardware, software and services, to the computer, business and telecommunication industries. Within standards its activities are 1. Exchange carriers. aimed at ensuring consensus amongst its members on the long term 2. Inter exchange carriers and resellers. direction of the industry. 3. Manufacturers and vendors. The standards activities within CBEMA are administered by its 4. Government agencies, consultants and other users and general Standards Programme Management Committee (SPMC). The Com- interest groups. mittee does not make its own standards, but instead participates in other groups developing standards. The T1 is composed of specialised technical subcommittees. Its In 1960 ANSI accredited the X3 Committee (Information Pro- output goes into ANSI for review as an American National Stand- cessing Systems) to develop American National Standards in the ard, and it also provides and input to the US CCITT where T1 area of media, languages, documentation and communications re- formulates the US industry view on CCITT standards. T1 also lating to computing devices and systems. Ever since it was formed produces reports for industry. CBEMA served as the secretariat to X3. The T1 has six technical committees, each with working groups In addition to its sponsorship of X3, CBEMA has also been which are set up as needed. It also has an advisory group (T1AG) appointed by ANSI to be the technical administrator of the US which manages its day to day activities, between T1 General Meet- Technical Advisory Group (TAG), which is responsible for develo- ings. The main T1 committees are: ping the US contribution on information technology standards to ISO and IEC. T1E1, which is responsible for standards relating to interfaces for user access to telecommunication networks. It concentrates on the physical layer and covers, for example, ISDN physical 22.5.5.4 lay