I got two OpenVox A1200P working with elastix with no problem, except DTMF detection problem which occurs from time to time.
Here is the solution from Digium FAQ:
Zaptel DTMF Detection Problems
DTMF detection problems can be caused by a number of different factors. The most common is running the X Windows System.
Another cause of DTMF detection problems is the relaxdtmf option in Zapata.conf. It may need to be turned on or off.
If you need to force all DTMF detection to be done in software, you can set vpmdtmfsupport to 0 in wctdm24xxp.c or wct4xxp.c and recompile, or you can specify it as a kernel module option at runtime.
You could use "modprobe <modulename> vpmdtmfsupport=0", or add a line in /etc/modprobe.conf (or whatever your OS uses) to add an options line.
I tried with relaxdtmf, disabling echo cancellation...but with no success. Now, I want to try with the last option, but I don't want to recompile Elastix (dahdi) files, also I don't know which of the modules I should load with vpmdtmfsupport option and where to do it. A1200P uses opvxa1200 module...
If someone experienced similar issues, please help !
Please execute the following command to record the fxo channel and send the file to my email or give me your ssh,i will help you to check it
# dahdi_monitor 1 -r r.pcm -t t.pcm (1 is the channel number which you want to record )