CCITT (Comité Consultatif International Téléphonique et Télégraphique) is the former, but still widely used, name for the ITU-T, a Geneva-based organization that sets international communications standards.
The ITU-T coordinates standards for telecommunications on behalf of the International Telecommunications Union (ITU). The ITU, founded in 1865, may have been the world's first intergovernmental agency; it became a United Nations agency in 1947.
CCITT has defined many important standards for data communications, including Group 3, the universal protocol for sending fax documents across telephone lines; Group 4, a protocol for sending fax documents over ISDN networks; V.90, the standard for full-duplex modems sending and receiving data across phone lines at up to 56,600 bps; X.25, the most popular packet-switching protocol for WANs; X.400, the universal protocol for e-mail; and X.500, an extension to X.400 that defines addressing formats so that all e-mail systems can be linked together.
Created November 2, 2005.