Hi, Thing is Skype is a pure p2p software (i.e. client). It will never stop trying to registrer itself or call to a remote party until it finds a single port that is not blocked at the moment. So, if you want something like Skype, then you'd have to make your own SIP client :) Nathelper is just a module in SER. It is a LINK to mediaproxy server. So, in other words, nathelper and mediaproxy are work as one ( or should i say they work together). Nevertheless, mediaproxy is a good solution for NAT. Maybe not the best, but at least it worked and still working for hundreds of people. Andrey. On 9/6/06, Asep Saifudin <aseps2000(a)gmail.com> wrote: