ATIS/ANSI 0600401.2006(R2011)
This standard provides requirements for loop-start and ground-start signaling for the analog voicegrade interface between carrier switched access lines and customer installations. These requirements are intended to assist carrier, manufacturers, and users of products to be used in the switched network to understand the characteristics of the existing networks. This standard is a revision and compilation of T1.401-2000 and its supplements T1.401a-2000 and T1.401b-2002, which it replaces in its entirety.