I have some strange behaviour that I am struggling to get to the bottom of. I am using the latest Vital PBX 4, and I am having this odd issue with ring groups that are set to ring all. I can see that all the extensions are ringing at the same time in the Reports > PABX Reports > Active Calls page, the actual phones seem to alternate with who rings first for one ring and then other phones begin to ring.
I have no audio issues or delays, all bye messages seem to be received correctly when calls terminate, so i don’t suspect any firewall issues.
I am out of ideas, looking for any help available, please?
This system is on-premise. But we spot the problem. It turns out to be the external DNS. We put all hosts and domains on /etc/hosts and the delay vanished.
Take out: never trust external DNS for critical operation on Asterisk. Never!
In my case, the host file was referring to the incorrect hostname/fqdn of my on-premiss pbx. after I corrected the host file (and removed the ipv6 references), rebooted and the issues with the delays went away!