BT Line using a X100P? card

Frankly it is not worth it. Getting a Sipura SP3000 or something similar to work is much easier. The X100P? price is extremely tempting, but it s clearly not well suited to the BT Caller ID signalling. Other providers which apparently use bell signalling are likely to be OK.

Caller ID

The patches for this maintained on LuSYN? did not work for me. They applied cleanly to Asterisk 1.2.4 sources and the resulting zapata and asterisk installed and ran without any callerID. There were some messages about failing to obtain history in the asterisk logs which did not provide enough information to pinpoint the problem. Enabling debugging on the zapata channel in asterisk resulted in crashes and no usefull information. Overall it looked like a long debugging session on a codebase I am not familiar with so I decided to leave it as is and work around it.

After some tweaking and finding a suitable modem I now use a sanitized version of the well known modem hack described here. Note that the code as posted there will never work as is. Writing the init string this way to a modem has no result. The modem should be initialised using chat or expect with "AT S7=45 S0=0 L1 V1 X4 &c1 E1 Q0 #CID=1". In addition to that, at least USR does not keep the #CID setting across ATZ commands and DTR drops so every time the modem is reinitialized it will end up with CID detection disabled. It is not written to the profile either. And on top of all the modem loses this setting once in a while so it has to be reset with it at least once every 24h.

Echo Cancellation

Zapata sources must be compiled with the linux26 target and run under Linux 2.6 to provide echo cancellation when using the X100P? card. With the MARK2 algorithm selected in the Makefile the echo cancellation is quite reasonable. It may be necessary to adjust the txlevel a bit to ensure that the people on the other side hear you OK and there is no distortion.

It is also essential to select the corect DAA mode. The card defaults to DAA mode 0 which is FCC and which does not set the line impedance and gain correctly for UK lines. This is immediately visible in dmesg: wcfxo: DAA mode is 'FCC' (correct for EU is CTR21). Note that the information on X100p clones in the VOIP Wiki is not quite correct. The newer Wildcards can be programmed for correct line parameters and setting opermode definitely makes a difference. For UK modprobe needs to be passed a "opermode=1".

X100P? Caveats

reloading chan_zap.so in asterisk 1.0.7 (debian sarge package) sometimes will not set gain values correctly to the new values in the conf file. You need to restart asterisk to get it to reset the values.

-- AntonIvanov? - 13 Nov 2008