Update:
My customer's installer downgraded their loaner box to 7.4, and still had the same issues of crashing every 6 hours, so it is not a sftw issue. So I had him unplug the WAN port for a weekend, and the system stayed up the whole time. Soon as it was connected again, back to 6 hour crashes.
So this is definitely not a hardware or sftw issue. Customer did pay the installer to install a firewall at install but the one they wanted to put in was back ordered. Hopefully they will get that in soon. If his system is being attacked then that should solve it. If it doesn't, than this must be a Broadvox issue. So a new SIP provider might be the next step if they can't fix it.
Not there yet, but at least we're narrowing it down.
Thanks all for the input, I'll post resolution once we get there.
