[Asterisk-Users] Sangoma A104D is dropping DTMF digits during IVR

[Jay Dutt]

I have the following pbx setup: asterisk 1.2.9.1, IVR setup, Sangoma 
A104D PRI card with HW echo cancel, hw dtmf detect. When calling inbound 
(from a cell phone or wired home phone) I can get the pbx to recognize 
the digits I type in for my extensions 100% of the time. However, when 
dialing inbound from a cordless home phone, the pbx drops the first 
digit or the first two digits (eg. I dial "1201" but the asterisk 
monitor indicates that only "201" or "01" gets detected). This is more 
acute when the Background voice has speech going (not pausing) but less 
so when the Background voice has pauses (ie. if I dial digits at the 
pause at the end of the Backround voice's sentence, I have a better 
chance of getting my digits recognized). Outbound digits seem to be 
recognized (when inside operators dial to external IVR systems). Dial 
plan is pretty standard, starts like this:

exten => 6100,1,Answer
exten => 6100,2,Wait(1)
exten => 6100,3,Background(mainmenu)
exten => 6100,4,WaitExten(${WAITEXTEN_TIME})
... etc

On zapata.conf, current rxgain/txgain settings are 0.0. I've messed with 
many combinations of gain parameters both positive and negative. I had 
better results when I had positive rxgain value of 16 and negative 
txgain value of -8. But my customer reported dropped calls, so I quickly 
set back to 0.0/0.0.
Per Sangoma tech support recommmendation, I also turned OFF the HW echo 
canceller in the wanpipe congig files. This had no effect. I am on 
latest Sangoma beta4-2.3.4, btw.

Has anyone usnig Sangoma A104D experienced this issue, and is there a 
way to get rid of it? If I cannot find the proper solution, I will 
likely swap out and try new Digium TE212P as replacement. I have 
reported to Sangoma that this is occurring on another pbx installation 
as well with the same card.