Editing Signaling (telecommunications) (section)

===Compelled signaling===
[[Compelled signaling]] refers to signaling where the receipt of each signal from an originating register needs to be explicitly acknowledged before the next signal can be sent.<ref>{{cite web|url=http://www.its.bldrdoc.gov/fs-1037/dir-008/_1159.htm|title=compelled signaling|publisher=National Telecommunications and Information Administration|access-date=11 April 2012}}</ref>

Most forms of [[R2 signaling|R2 register signaling]] are compelled, while R1 [[multi-frequency signaling]] is not.

The term is only relevant in the case of signaling systems that use discrete signals (e.g. a combination of tones to denote one digit), as opposed to signaling systems which are message-oriented (such as SS7 and ISDN Q.931) where each message is able to convey multiple items of formation (e.g. multiple digits of the called telephone number).