Problem with DTMF on vintage phone

[chetstone]

Hello,

I'm trying to use an old Western Electric 500 series phone with the OBI 110. The touchtone buttons don't function when I'm on a call, such as trying to select options when checking my google voicemail.

I know line polarity has to be correct in order for the dialer to function on these phones. I have a polarity checker and the lines check OK... Anyway, the buttons work OK when dialing a call, just not when the call is connected. When the phone is connected directly to my POTS line it works fine. The problem occurs when connected to the OBI, whether I am dialing out through GV or the pots connection.

Any ideas?
thanks...

[RonR]

Try setting:

Physical Interfaces -> PHONE Port -> Tip-Ring Voltage Polarity -> ConnectPolarity : Forward

[chetstone]

Yep, that worked. Thank you!