I have a small configuration with SPA9000, SPA400, 2xSPA921 and 1xSPA941 with both the FXS ports used for analogue handsets.
The system works mostly OK, but I have a strange "feature" that will not ring the FXS ports when my mother in law phones (caller ID is enabled on the PSTN line) although the SIP handsets all respond correctly.
Hers is the only incoming number that this happens to.
There are no incoming routes based on callerID, and I have rebooted all parts of the system.
Any thoughts on why this could happen?