The out of band signaling channel in a 2B + D ISDN circuit (see entry). Constitutes 16kbps of bandwidth, which is in addition to the 128kbps of B channel data possible with ISDN.

The channel through which data is transmitted in CAS mode.

See input/output channel.

(1) Unidirectional data transmission path with transmission terminal equipment at both ends. (2) A 16 kpbs or 64 kpbs channel reserved for signaling and other packetized services in an integrated services digital network (ISDN) configuration.

An information channel which transports data, usually for remote control or supervisory purposes or sometimes broadcast for public reception