Visit our newest sister site!
Hundreds of free aircraft flight manuals
Civilian • Historical • Military • Declassified • FREE!


TUCoPS :: Phreaking Technical System Info :: trunksig.htm

Basics of Telephony Trunk Signaling



Trunk Signaling

Trunk Signaling Schemes

It is necessary to understand the signaling that occurs on trunk circuits. Signaling states include ON-HOOK and OFF-HOOK supervision, Disconnect supervision, dialing supervision (Pulse Dial/Tone Dial), and Start Dial supervision.

Most signaling schemes use DC currents to represent signaling states, but analog (AC) systems also exist that use tones to represent specific states.

The following subsections discuss the types of signaling:

2-Wire Loop Start Trunk Signaling
2-Wire Ground Start Trunk Signaling
SF Signaling (AC Signaling)
E and M Signaling
Start Dial Supervision



Other text on Signaling

Analogue Signalling Systems By  NeonDreamer
Branches Of Signalling         By  dialect
Telephone Signalling Methods       By  Doom Prophet
Signalling Systems         By  Unknown






TUCoPS is optimized to look best in Firefox® on a widescreen monitor (1440x900 or better).
Site design & layout copyright © 1986-2014 AOH