SSN

Sub‐system Number. Identifies the sub‐system within an SS7 network element.

GSX / SGX

A Sonus‐specific media gateway that converts a traditional wireline call into a VoIP call. One variant, SGX, converts SS7 signaling.

PPSS

PSAP Premise Serving Site.

PDM

SnapTrack Position Determination Module, consisting of a location server and a WARN manager.