Mediatrix manufactures a wide range of media gateways to connect legacy PSTN interfaces (FXO, FXS, BRI, T1/E1) to ScopTEL.

For reference please visit the Mediatrix website here
This how to presentation provides in depth instructions on deploying a Mediatrix analog gateway with ScopTEL.

ScopTEL - Mediatrix Analog Gateway Configuration