No Ringback from PSTN to Lync via Audiocodes Gateway

Problem:

We had an issue where when calling a Lync phone from our PSTN with a Mediant 1000 Audiocodes device between Lync and the PSTN we were unable to hear ringback tones from the Lync device on the PSTN phone.

Answer:

This problem is one of those issue were there was 1 drop down option that needed changed to resolve it.

On the Audiocodes Gateway, go to Configuration > Full > SIP Definitions > General Parameters.

Go to the option Playback Tone to Tel and change it to Play Local Until Remote Media Arrives. Click Submit.