MF (Multi Frequency)

MF (Multi‑Frequency) is a type of in-band signaling used on analog interoffice and 9‑1‑1 trunks.

Enhanced MF (Enhanced Multi-Frequency), E-MF

A signaling protocol, used on the E9‑1‑1 tandem-to-PSAP interface, that is based on the Feature Group D (FG-D) protocol and supports the delivery of up to two 10-digit numbers, the first of which is preceded by two ANI information digits (i.e., ANI “II” digits). Telcordia GR-2953-CORE.


 * NENA 03-002, NENA Standard for the Implementation of Enhanced MF Signaling, E9-1-1 Tandem to PSAP
 * NENA-STA-027, NENA E9-1-1 PSAP Equipment Standards