sundance-communications.com Forums Telephony Discussion Phone & VoIP Systems ESI Telephones & Systems ESLink echo

I have three sites; 2 with ESI50-L systems and one with an ESI-1000. We are experiencing a terrible issue with an echo when using esilink between either of the ESI-50 sites to the 1000. The users at the 50 sites states that the echo is their own voice. Any idea what would be causing this type of issue?

Here, this will help you.

https://www.voipmechanic.com/echo-technical.htm