This is fairly specific, but I didn’t find any posts out there to help me.
If you are using an older Freepbx with Asterisk 1.4 or 1.6 and you want to include a ZAP or DAHDI channel in a paging group, but it never rings the FXS channel, then you need to examine the dialplan.
I noticed that when it reached this point (- Executing [PAGE203@ext-paging:2] ChanIsAvail), it would hangup.
After tinkering I realized that it was checking on ZAP/4 (my channel in this case).
-Go to the extension in Freepbx, and under the “Dial: ” options for that extension, change it from ZAP/4 to DAHDI/4.
Apply and now when you see it doing the Chanisavailable check it will pass and should call your FXS line.