[Asterisk-Users] Status of ISDN && DTMF (AFAIK): Please add corrections and comments

[pedro bulach gapski]

In this message I try to summarize what I have learned in these last two weeks. My primary sources of informations were the * list archives and linux ISDN docs. I ain't no * master, so don't trust too hard.

Relevant messages from the * list for the current discussion are: 009177.html 009268.html 0498.html 0849.html

My setup is an Eicon Diva (HiSax: Eicon.Diehl Diva driver Rev. 1.1.4.2) running on standard debian woody.

First configure your card and make it work with minicom or something like it, then go for *. The relevant part of the modem.conf file in my case is:

msn=XXXXXXXX
incomingmsn=*
group=1
device => /dev/ttyI0
device => /dev/ttyI1
features=dtmf,noquelch

In that setup, in extensions.conf I dial with the following line:
exten => _9NXXXXXXX,2,Dial(Modem/g1:${EXTEN:1})
Use Modem/ttyI0 or Modem/ttyI1 if you have channel preferences.

After a standard instalation and setup, my DTMF detection was unreliable. I received 1,2,3, sometimes 7,8,9, and never 4,5,6. First thing I tried (see the cited messages) was a kernel upgrade to 2.4.21 (woody has 2.4.18). AFAIK, this solved the problem. However, based on discussions on this list, I went further and tried the patches referenced in the messages (thanks to the authors!). I patched the kernel and a few modem related files in the channels directory (Pauline Middlelink's patches). Everything is working fine now for DTMF detection.

Current problems are: 
-outbound calls (h323->*->out) to analog phones have echo. This gets better with a better mic, but does not disappear. It seems that no solution to this problem is available.
-my callees complain of the silence supression. I have not looked at it yet.

Please correct and comment.

pedro