[asterisk-users] Re: DTMF Corruption Problem

[Eric "ManxPower" Wieling]

Justin Tunney wrote:
> UPDATE:
> 
> I've installed ztdummy and have chan_zap.so loaded in to the system so
> Asterisk can use psuedo zap channels or whatever it does for timing.
> I also specified relaxdtmf=yes in sip.conf.
> 
> DTMF is still completely awful.  Digits are still getting doubled up
> and my IVR is still nearly impossible to use.
> 
> I'd like to note that I'm using Bandwidth.Com (A Level3 reseller) for
> SIP VoIP service.  I did not experience this problem before with my
> old VoIP provider Gafachi.
> 
> Does anyone have some tips on trying to debug this further?  Are there
> any commands I can put in to tethereal that will give me debug
> information on RFC2833 in the RTP stream?

relaxdtmf does not apply to out of band DTMF.  With Level 3 only INBAND 
DTMF will work and the codec must be ulaw.