FreePBX Distro 15
D40, D62 series phones
EPM with DPMA
I’ve had this issue crop up in a few sites. It’s worse with the newer D series phones (D62/D65’s). Everything seems fine but after the phone sits unused for a while and the user goes to dial out, by dialing the number then pressing the dial button, the phone display show’s the call is on “hold” and they get a busy tone.
Hang up, dial again and the call goes through.
It seems like the phone loses connection with the PBX but when looking at the dashboard no indication of phones dropping is every shown. Also, the phone rings every time on inbound calls.
Other issues also occur like not being able to retrieve the voicemail list or parked call list randomly.
Interestingly, the D40 phone in the office does NOT have these issues. If it were a network issue I’d expect all phones to display the behavior.
The PBX is on a Vultr VM and there is a site to PBX VPN set up using Strongswan between the office router/firewall and the FreePBX system. Running MTR from the PBX to the public IP of the office Route I see no packet losses and ping times hover around 12ms.