I don't know much about networking. Is it less "user friendly" if I disable UPnP? Would I have to open up ports for various applications I might have running?

As per my last post, I changed all the configurable devices to use static IP except for the VOIP box. I haven't had a lockup yet. So I'll continue to let it run this way and see what happens. But I will look into UPnP. Thanks for the tip!

Yes, you will need to open up ports manually. However, you would have probably still needed to open the port as well in your firewall. Keep in mind that we are talking about incoming non-established connections. With more than one network host, you still would need to decide which host to forward to. ( Established incoming traffic is generally allowed by your NAT router and the firewall on your computer.)

Your router may be able to log the traffic. If a log shows ingress traffic for the VOIP phone, it may also list which port is used.

I just got an internet phone myself. In my case, the phone is before my router.

It looks like static ip might have fixed the problem. I've left it on for more than a week and it's still going strong

I now have a problem with ssh...but I'll open another thread for that. Thanks everyone!

This would do it although it would only appear locked up via ping. It wouldn't be locked up the ping just wouldn't be able to reach it nor would any other machine make it to the internet that is using it as the default gateway.