[Serusers] SER + Proxy + NAT

Edson, Putting a NAT traversal solution behing NAT is a chicken and eg problem, isn't it? -- Adrian Hi all... I look through the list's archives, but an not finding info to help me. The goal is use SER but not instaled in the GW/FW (it's not an acceptable option, well it's acceptable, but not for now). So I'm trying to put the SER in the Internal LAN (it could be installed in a DMZ also). So the question is if there is any proxy that could be putted on the GW/FW to handle incomming calls (INVITEs) and forward it correctly to the SER machine taken over the NAT issues? I already look at SIProxd and RTProxy, but the first didn't forward incomming calls, and the second demands that it be instaled, with SER on the GW/FW. I also am looking at SERMediaProxy (RTProxy alternative) but the documentations aren't sufficient detailed to answer my question. Any help would be appreciated. Edson.