I have an installation that is experiencing phantom calls from one phone to another. There are only a couple of phones making the calls. Looking in the call log of the phone itself it does show the phone calling another phone for approx 20 seconds. IF someone is in the same room as the calling phone you will hear it go off hook and hear the call progress tones to the other phone and eventually the voicemail greeting, then it hangs up. The CDR report reflects that the phone did make the call. we have replaced the phone with the same model / maker of phone 3 times. I have requested pacp files for the IP address of the phone. Looking at them they look normal with one exception. Instead of the IP of the phone system responding to the phone the WAN IP is present. Here is an example of that I am trying to explain:
What I would suggest is to configure your phones to disallow IP calling and to only accept calls originating from your SIP server. This is different depending on the type of phone
Disabling guest access may require updating to chan_pjsip, if you are still using the legacy driver, as, for some providers, who can source calls from a wide range of addresses, it is the only practical way of handling incoming calls.
To the OP, please always say which channel driver (and FreePBX and Asterisk version) you are using.
Not part of the original issue but is bugging me. The server is on the local network to the phone, so why is it sending the WAN address instead of the local IP of the system? NAT on that extension is set to NO