Tele-Communication (Telecom) Terms Glossary and Dictionary
Quadruple Order Tone
Quadruple Order Tone is one of the Order Tone (See Order Tone). This signal is four short spurts in quick succession and means that the operator should pass the city name only and wait for another challenge. It is used in manual toll tandem (also called zip tones or trunk assignment tones). Quadruple-order tone is four short spurts of High Tone.