Adrian, I am not an expert but spent the last 3 weeks fighting with both. :-) In short the difference between mediaproxy and rtpproxy (nathelper) that it are both mecahnisms to transparently penetrate symmetric nat in conjuction with ser and with some help also a-symmetric. Mediaproxy can make use of multiple proxyservers to balance your proxied traffic. Also mediaproxy tries to move the complex logic of the decision in the module or the proxy servers , unlike the nathelper module which has most of the decision logic in the many options you can pass to its various functions. Both are working well although i have the feeling that there is way more experience with nathelper on this list. My choice is mediaproxy because i need to handle a very high volume of nated ep's that i like to balance over different proxy servers. These were my 5 cents on your question.. Tjapko. On Fri, 2004-06-04 at 21:42, Adrian Acosta wrote: