Thank You! I have tried your settings and still have an issue. I have tried 1,2, and 7 with DTMF...no luck. We have Windstream (KY)at this location. 1 ring can work with the Audiocodes unit with them, but all FXO units need 2 rings with Bell South ATT (around this area) from my experience. The caller ID is not that big of a deal, but the DTMF is. The audiocodes units need out of band here...FYI. I am getting the same result with both identical units. I even tried it on their 503 unit.