I have posted about this before but I have unfortunately not yet managed to identify the root cause of this problem. Sometimes, I’ll receive an incoming call and it will ring a Ring Group, but the call will get lost and there will be loads of “1 second calls” from “unknown”. If I pick up one of the phones, all I will hear is the dial tone, whilst the other phones in the group will still be ringing.
It’s such a strange problem and I am still quite new to FreePBX, so I am not totally familiar with troubleshooting the routing of calls. When I look at the CDR Report though, it shows 4 “1 second calls” with the callers CID and then the rest is 1 second calls, all with unknown CID? Even though this was a scam call, I’ve covered the number in the screenshot but where there is red, is where FreePBX had the callers CID and this shows on the phones on the first 4 rings, but then shows “unknown” for the remaining 1 second calls.
Just encase anybody else has the same / similar problem as I had here, I think I have managed to resolve it by following the steps provided by @Stewart1 on one of my previous threads - FreePBX and Grandstream HT813 - #9 by Stewart1. I have not experienced this strange problem since applying the configuration mentioned by Stewart. Thank you @Stewart1!
Just to add to this, the above unfortunately did not fully resolve the problem but changing this value on my Grandstream HT813 appears to have fully resolved it.
I had this set to “2”, which I have changed back to “6”. Since changing this, the weird call looping has stopped. I noticed this timeout showing in the syslog output of the HT813 and it was after two seconds, the call would go crazy.
I am an IT Analyst, so this isn’t my area of expertise. I am relatively new to this area and started it purely through interest of wanting to learn more about digital phone systems. I only use my set up at home and one of the main reasons I went down this path was to properly combat scam/nuisance calls, along with having the added benefit of having phone hardware anywhere that has power/power over Ethernet/Wi-Fi.
I am a medical doctor by training
Have been using freePBX at several locations for many years, but I am no pro.
I usually install it on Intel-NUCs (Linux Mint) as a Virtualbox machine.
At home I ported the phone number to a SIP-trunk provider too.
It is amazing how reliable and stable this free software is…
