DTMF problems


I have * 1.2 installed and use Xlite as my SIP client.
I updated my voicemail to realtime, and Im sure it works fine, but I have not net been able to use it beacuse Asterisk seems to receive duplicated DTMFs in my SIP calls

Im using gsm codec and I have configured SIP to use rfc2833 in both server and clients. I have also enabled the relaxdtmf switch in the SIP configuration file, but always get the same results: asterisk receives each digit twice.

I can see the DTMF duplicated in the * console. this is the output I get :

id => 2
customer_id => 0
context => isp
mailbox => 2099
password => 2099
stamp => 2006-01-02 09:11:30
– Playing ‘vm-password’ (language ‘en’)
– Incorrect password ‘22009999’ for user ‘2099’ (context = isp)
– Playing ‘vm-incorrect’ (language ‘en’)

This problem is present with other SIP softphones (i have also reproduced the problem with kphone).

Can anyone give me an address with this issue :question: Im using Asterisk 1.2.0

Thanks in advance.

Juan Cuervo

gsm codecs are terrible in dealing with DTMF. I’m suprised that you are even getting that far. Switch to a g711u/a codec and make sure that you are using the same dtmf method systemwide.

Thanks for your suggestion.
This problem is very misterious. I have tried everything and finally it seems to work fine with asterisk 1.2.0 and gsm codec.

We are using gsm because it requires less bandwidth, and we are not plenty of it here.
But I will consider your advice very seriously and enable it in my configuration, so that users with good bandwidth (>128k) will be able to use it.

Thanks a lot.


To each his own. I dumped g711 because the audio was choppy and full of digital artifacts. I forced GSM as the only option, and I have no problems with Asterisk reading DTMF tones from X-Lite.

EDIT: Just a far-out theory here, but if it’s a data stream going through UDP, is the PBX getting duplicate packets?