Matthew,
Welcome to FreeSWITCH! We're glad you're ditching a $120K system. We think you'll find FS is as powerful as any software out there right now.
Here's a handy wiki page that will help you get the diagnosing skills you need:
http://wiki.freeswitch.org/wiki/Reporting_BugsI'd say first thing to do is capture the SIP traffic to see if there are any clues. A "normal temporary failure" doesn't give you a lot of detail. :) If you're new to SIP debugging then the best thing to do is to capture the SIP trace and put it in the pastebin. (
http://pastebin.freeswitch.org)
You can also join the IRC channel #freeswitch on
irc.freenode.net and get some real-time help. There are some sharp folks in there, not the least of which are the three main FreeSWITCH developers.
-MC