I’m a complete n00b with Grandstream ATA adapter - HT813.
I’ve successfully added my PSTN number to FreePBX, but I see that device is not registered, I can however send and receive calls. It registered as trunk in FreePBX thought!
There are endless of settings, so it might be that I missed few ones.
There may be nothing wrong. Assuming that the HT and PBX are on the same LAN subnet, a static configuration where each device is configured with the IP address of the other is reasonable. Some users prefer that because ‘lost registration’ is not possible. The PBX can still use qualify to confirm that the HT is online. The only disadvantage is that the PBX must be manually configured with the HT’s IP address.
I don’t remember, but believe that the FXO indicator is normally off, lights up when the line is in use, and flashes when it is ringing.