ptrowski,

I bought a Linksys SPA2102 to solve my DTMF talk-off issue (as well as the known NAT problems with newer Linksys routers). It has a DTMF "strict hold off time" setting which the PAP2 did not have in the earlier firmware. I don't know if the latest 5.1.6 firmware has this "strict hold off" setting, but if it does maybe you can ask tech support to try the settings below.

The "Inband+INFO" was needed instead of "Inband" only to maintain compatibility to Voipo VM system. I had to move the Strict Hold Off Time from the default value of 40 to a value greater than 90 to eliminate the DTMF talk-off.

Hope this helps.

DTMF Tx Method: InBand+INFO
DTMF Tx Mode: Strict
DTMF Tx Strict Hold Off Time: 100