[GnomeMeeting-list] newby question. Problem behind a NAT

[Andreas Fromm <afromm physik uni-erlangen de>]

First of all, hi to everybody.

I just started to play a bit with gnomemeeting as I got myself a Webcam
an want to videochat with my brother. We are both running gnomemeeting
(1.2.3) from debian/testing. Both of us are behind a DSL/Cable Router
with portforwarding for ports tcp:1720, udp:5000-5016 and
tcp:30000-30010. The problem we ar getting is that we can make and
receive calls, have text chats, but no sound nor video is transmittet.
The calls get killed after the timeout for inactive calls, unless we
turn off that feature. Our webcams and sound configuration seem to be
working all right (we can see ourselfs on our local windows) and the
comunication between two of my computers at home work all right, so I
think it's a NAT problem we are having here, but I don't know what else
to do. I allready looked at the FAQ and searched the mailing list, but
couldn't get any thing usefull. We also tryed out different NAT
settings, with and without stun enabled, using automatic IP checking etc.

I hope someone can halpe me!

thanks in advance

Andreas