I have been experimenting with mumble/murmur trying to set it up on a server at my work behind a sonicwall firewall appliance. I connect without issue but no sound gets through. I think I may be having a configuration problem with the firewall rules, but I am having trouble telling for sure. I think it would be fairly easy to implement a diagnostic mode where the client tells the server how many packets it sent in the last broadcast over the TCP connection, and the server would reply back (also over TCP) with how many packets came through. This would also give info on general packet loss that I think might be helpful to some.
I'm no expert, but... could it be that UDP packets are being blocked? Since the sound is, by default, sent as UDP packets, this would seem to me to explain nicely why you can connect, but not get sound through.
That is kinda what I was thinking. I have both UDP and TCP mapped on that port, but I am wondering if the sonicwall is having trouble because both rules are using the same port number. It shouldn't be a problem, but maybe on this firewall/NAT it is? I haven't looked in any knowledge bases yet. Won't be a problem soon, I have a new job in a new location in mid-August and I doubt they will let me use their network for my own purposes as I could here.
Anyway, Slicer says 1.10 already has some packet-loss statistics built in and it will tell you if it isn't getting any UDP, which should be enough info in this case.