Pap2 and random DTMF beeps

I have a few PAP2 devices on my PBX and I seem to frequently get what sounds like 4-5 shourt DTMF beeps played to outside callers during a conversation. I beleive this is refered to as talk-off. These beeps are not heard by people inside the office only outside parties can hear the beeps. I have read elsewhere that a possible fix is to make the following change:

  1. In your PAP2 html interface, go to /admin/advanced, Line 1 and Line 2 and set DTMF Tx Method: INBAND in both places. (was previously set to Auto. Also DTMF Process INFO and DTMF Process AVT both are set to YES)

  2. For extensions mapped to the PAP2 Line 1 and Line 2, we went into FreePBX under “Extensions” and set the dtmfmode to: “inband” for those extensions. (was previously set to rfc2833)

I have Bandwidth.com trunks and my trunks are currently setup with dtmfmode=rfc2833. I am wondering if I make the above changes will my Bandwidth.com trunks still function correctly or do I also need to make a change of dtmfmode=inband in my trunk setups? Does Bandwidth.com even support Inband? I also have aastra 57i phones in my network that work great so I am also wondering if this change will break my aastra phones.

Any advice on this topic would be greatly appreciated.

Of all the problems and issues we have encountered with Asterisk (and it is, basically, an Asterisk issue) one of the most annoying has been the way touch tones are handled, or not handled as the case may be. Using INBAND solves some issues but can create others. For example, we had one of our remote users using INBAND (set at both their PAP2 and for their extension in FreePBX) and they were unable to move through the voicemail menus. I changed our end (FreePBX) to RFC2833 while leaving their end at INBAND - suddenly they could access their voicemail, but I warned them it might cause other issues down the road. Since I don’t converse directly with that particular user often, I don’t know how that might affect the spurious tones (which I’ve also heard on occasion).

This is one of the things that I’m hoping works better in FreeSWITCH - I’ll need to wait for a release version to try the FreePBX + FreeSWITCH combination, but I’m really hoping that this is one of those things that the FreeSWITCH people will properly address, if they haven’t already.

Caveat: I’m still using a 1.4 version of Asterisk. These issues may have been resolved in 1.6, but I have no way of knowing at this point.

Thanks for the reply.

I too am using 1.4 as I have not wanted to take the plunge to 1.6 and whatever problems it might create. My 1.4 is working great except for these PAP2s and their random DTMF beeps. Do your trunks support INBAND because I’m not sure if bandwidth.com trunks do? I was thinking that changeing the PAP2 to INBAND and not changing the extension also could cause a lot of problems. From your post it sounds like you have a PAP2 setup for INBAND but have the extension setup for RFC2833. Are your PAP2s still able to make successful outside calls?

Thanks