[Serusers] Question about Mediaproxy and NAT'd clients.

Hello. I have a question about the Mediaproxy and NAT'd clients. I am trying to use the Mediaproxy module to solve the NAT'd clients problems, until now i have all the scenarios working ok, but i have a question. I'm using the ser.cfg configuration example in the /modules/mediaproxy/config directory and i have three clients, one is behind a NAT and the other two are using public IP's. When i call from the NAT'd client to the Public-IP client the call is going through the mediaproxy, and that's ok. In the same way when i call from a Public-IP client to a NAT'd client the call is going through the mediaproxy, but when i call from one Public-IP client to the another Public-IP client the call is going through the mediaproxy too. I think this is not normal. Does the ser.cfg file example work in that way? I suppose that in a normal enviroment a call between two Public-IP clients the media goes directly between them, and there is no mediaproxy in the middle. Can someone provide me a ser.cfg example that works on that way?. I'm a liittle bit stuck with this issue for a while. Thanks in advance. Best Regards Ricardo Martinez