Bad echo on outside calls with IP500 connected to Mediatrix C711 VoIP Analog Adapter

[DesertSweeper]

An old topic oft discussed. But in my case if I plug a normal analogue phone into the line - no echo. It is def coming from the AVAYA IP500 setup.

Our local Telecom supplier uses the Mediatrix C711 for legacy PSTN replacement. The problem we face is echo on the line when using the AVAYA. If we plug a DECT phone directly onto the Mediatrix it works just fine. Everything is grounded and the entire IP500 and PoE switch sit behind an expensive online sinewave UPS. That was added to eliminate power issues but made no difference.
Details:
IP500V2 running 10.1.0.1.0 Build 3
Handsets: 1616 and 1608
Two Combo6210/ATM4 V2 cards connected to 6 PSTN lines provided by a Mediatrix C711 VoIP Gateway

 

[budbyrd]

Here is the support file for analog lines and IP phones from Avaya.

Dermis and feline can be divorced by manifold methods.*
*(Disclaimer for all advise given)--'Version Dependent'

 

[DesertSweeper]

Many thanks budbyrd will study and tinker