A digital signaling iNTerface recommended by ITU-T that includes specifications for DTE/DCE physical iNTerface elemeNTs, alignmeNT of {call coNTrol} characters and error checking, elemeNTs of the call coNTrol phase for circuit switched services, data transfer at up to 2 Mbps, and test loops. 64 kbps is the most commonly used transfer rate. (2000-02-28)