DTMF Broken in 1.4.24

Is anyone else experiencing a regression in RFC2833 DTMF functionality in asterisk 1.4.24?


Not here. Any specific way that you can produce it. I would try to test here and reproduce as well.

Yeah, it’s 100% reproducible. I simply need to try and authenticate with VoiceMailMain from a T-Mobile cell phone. I have 3 T-mobile phones (Blackberry, HTC, and G1) which all experience the issue.

If you look at the bug report I opened you will see that the RFC2833 duration for the cellular originated call is about 2x as long as a pure SIP device or any of my land lines. Asterisk is taking the single long event and translating it to two distinct DTMF events even though as per the RFC, the DTMF data is valid.

Dialing 1234 will result in asterisk detecting 11223344.

Can you re-produce from a land line ? I just realized that I am running 1.4.23 and I don’t have time to upgrade. I have a BlackBerry and 2 Motorola cell phones. If you want you can PM me a number to try by you. I do not have any test servers at the moment that I can load 1.4.24 on to :frowning: .

No, the landlines work fine. My carriers are sending shorter DTMF event durations than my cellular carriers.

Being that I can always reproduce on my server it probably doesn’t do much good to have you reproduce on my server :smile: I was hoping someone else could confirm the issue exists on their setup.


Try using dtmf=passthrough on your SIP trunk registration section in sip.conf. Also many SIP carriers “eat” dtmf in the audio channel. If you are pulling your SIP trunk through the 56 Marietta “Meet Me” room in Atlanta there are carriers availble there that can provide you with a 8xx SIP trunk (with 5k minutes on the cheap) that won’t eat DTMF in channel. PM me for more information.

this isn’t a carrier problem, nobody is ‘eating’ DTMF, it’s just a function of the duration of the DTMF event being longer coming from the cellular carriers.

take a look at the bug report for more details.


I should have a server to test on in the next day or two. Please hit me up on aim: dovi5988 and remind me to test.