Problem with battlecom and double masquareded packets

[Jan]

    Hello,
I have some Problems with battlecom (voice software) and 2 masqed machines.
The Problem is if i try with my machine (behind my netfilter linux 
router) to connecting to my friend (too behind a firewall).
I can't connect to there server but if i try to connect an server 
without firewall it will work. Now i want know how can i
try to get it work.


Sorry for my bad english im working at it



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Jan Killius