[Serusers] Mediaproxy and nat issue

Hi guys... I have this piece of code in my record route section... if (method=="INVITE" && client_nat_test("19")) { record_route_preset("some_internal_ip:5060;nat=yes"); # insert IP a$ } else if (method!="REGISTER") { record_route(); }; And the problem is... It works perfect for... lan to lan client... But it doesn't for lan to external side, If I change the "some_internal_ip:5060;nat=yes" To "some_externel_ip:5060;nat=yes" It works for lan to external, but not lan to lan... how to turn around it ? How is the best aprouch to have my re invites working ok, and how to be shure that my external clients will use my mediaproxy that is behind a nat also? It is a full port forward nat Clients - SER - - Mediaproxy - router - internet < - > Regards,