S, Standard> A digital Signaling interface recommended by ITU-T that includeSSpecificationS for DTE/DCE phySical interface elementS, alignment of {call control} characterS and error checking, elementS of the call control phaSe for circuit SwitchedServiceS, data tranSfer at up to 2 MbpS, and teSt loopS. 64 kbpS iS the moSt commonly uSed tranSfer rate. (2000-02-28)