[Users] Multiple mediaproxy instances

Hello, I have an openser box that has multiple interfaces each one with its own ip address and i was wondering how to run various mediaproxy instances in the same machine per ip address so I can have communication between interfaces and proxy all traffic coming and going between the UA, I have been trying to get information on this and I found that is valid to do this but I cant find any info on how to doit, actually if people can give me hint or a basic setup I could write a howto , actually im a newbe on openser but I can see a lot of potential if we had a basic manual and soma basic setup examples. Thanks a lot for your help. Fernando Rodriguez V.