I have a customer who is using a Spa 122 to connect to our Voip network. On inbound and outbound calls the far end party hears themself in an echo. We have tried adjusting the echo cancellation, Gain, settings for the fxs ports, and adjusting the firmware, but still the echo is present. Is there anything that I am simply overlooking or are the details that I may not be aware of that could be looked into?
