R2 Signalling

R2 Signalling

R2 is a 1950s- and 1970s-era channel-associated-signalling signalling protocol used outside of the former Bell System to convey information along a telephone trunk between two telephone switches in order to establish a single telephone call along that trunk.

R2 is the name given to two broad protocol groups: R2 line signalling and R2 register signalling.

Read more about R2 Signalling:  Information Conveyed Along An R2-signalled Trunk, Line Signalling, Register Signalling, Standards, Signalling Variants, MF Tones, Nomenclature