VoIP only fixed by resetting state table

[DanC]

Hey community:

I have a problem that occurs quite frequently, but I'm unable to troubleshoot the root cause.  Maybe someone else can point me in the right direction.

I have 6 UniFi Pro phones, UniFi VoIP controller, Elastix PBX, SIP trunk from Flowroute, and pfSense for routing/firewall (All my variables).

Occasionally, I'll pick up a phone and get "All circuits are busy now" after dialing a number.  This goes away after resetting my state tables in pfSense.  I've tried other ways to resolve this by rebooting everything, updates, etc.

I do have Multi WAN, failover to a DSL line if our fiber connection goes down.  It might be possible it's breaking when that goes down.  My fiber provider has been doing some maintenance the last few weekends.  Let me know if there's any further info required.

Thanks in advance,

Dan