We have a VOiP server (Trixbox CE, freepbx server v18.104.22.168) with approximately 75 extensions.
The server is in a datacenter, connected directly to an external IP.
We have 4 offices, each office uses a Sonicwall Firewall (NSA 2400, TZ100, TZ210 and a TZ200)
We are encountering multiple problems
1.) No voicemail.
The voicemail on the phone works fine most of the time, maybe 60%.
But other times we click on the voicemail button on our phones (Cisco SPA303)
There is no sound what so ever. Other times we can hear the computer voice asking for password, after the password is entered it says "you have x new messages" "to listen to your messages press one"
After pressing 1, no message is played and the computer voice says "to listen to your message again press 2" etc.
But if I log into the trixbox gui , I am able to listen to all messages there.
2.) IVR no sound
We have a IVR setup to route calls to specific extensions.
Sometimes when calling our main number there is no sound either.
I think the times are the same as the voicemail issue.