Description: When a user from a “Tanjay” phone calls a PSTN user across a voice gateway such as a Dialogic, the PSTN user doesn’t hear the white noise (comfort noise) typically present on traditional phone conversations. The PSTN user assumes the line has been disconnected and often will say “hello, are you still there?”.
Resolution (Dialogic): Typically you don’t want to enable VAD (Voice Activity Detection) on the gateway however this feature fixes this issue. From the voice gateway click on VOIP then Media and set the VAD to “on”.
Description: When an OCS user calls a PSTN user through a voice gateway, the audio levels rise and fall as though something is adjusting volume. Also at the beginning of a phone call the audio is lower than normal.
Resolution (Dialogic): Set the Automatic Gain Control (AGC) for both IP to TDM and TDM to IP calls to “off”. The reason for this change is that in R2 they included AGC as part of the base application. Levels are automatically adjusted at the client device (and server).
The ringback tone continues to play after the caller picks up
This issue is caused by the gateway not accepting “early media”. With the release of OCS R2, “early media” is a feature which permits OCS devices to complete the call setup quicker. The Dialogic gateway must be set to “Always” for this to function properly.
I hope this helps some of you out there.