We have a customer that are experiencing problems with distorted voicemail messages left for them.
Originally the customer was on a 406v2 with embedded voicemail on version 4. They were upgraded to version 5, no difference, then we replaced the embedded voicemail, still no change. We then replaced the main control unit to an IP500 version 2 again with embedded voicemail, still no change. We then swapped out an external DS module as it seemed to be affecting users who were connected to this, however still no change.
We also turned off re-invite supported on the SIP trunks, no change, turned the non-linear process mode to disabled, no change and added Conference_DSP_TX_GAIN=-4 to the no users source numbers tab, and again no change.
I wasnt involved in most of the testing for this, but have been investigating today and believe the issue started when their ISDN DDI numbers were ported to Gamma Myinbound and then on there forwarded to individual DDI number on Gamma SIP.
No issues have been reported at all with call quality when they actually answer calls only when the calls go to voicemail (and not every message left either).
The SIP trunks are set to automatic compression mode and user offerers preferred codec is ticked.
I am going to try turning the offerers codec off today.
Okay so did tests between typing the above and pressing post so thought I would add this update.
Changing the offerers codec made no difference both with it on and with it off used G711 as the codec.
I then tested by pointing an ISDN DDI that they did have to mytest extension and left a voicemail and it was perfect so it appears that the issue is being caused by calls coming in on the Gamma SIP trunks.
So need some ideas on what else I can try.
| ACSS SME |