[Serusers] RTP-proxy behind NAT

hello,

I was wondering if any one have had any experience on making RTP-proxy work behind a Firewall-NAT-Router like in this:

 [Nated Clients] | | [ROUTER--NAT--FIREWALL] (192.168.5.1 / 77.95.143.30) | [ Openser/RTP-Proxy] (192.168.5.40) uses Dispatcher module to distribute calls to asterisk servers | | | | [ASTERISK]1(.41) [ASTERISK2](.42) | | | | --------[T1/PRI/SIP/H323]-----

if so ,,how can this be achieve ?

Thanks

Vicox