this invention provides for uniformly distributing signaling data in a t1 line format for unrestricted 32 kb / s and 64 kb / s transmission channels . this scheme provides for placing a portion signaling information within each frame of a t1 transmission . digital switching systems may process this signaling information more uniformly , instead of receiving 24 channels of signaling information during one t1 frame . the signaling information provides the digital switching system with indications of such supervisory functions as on - hook , off - hook and switching digits .