Hi Almost there with the setup, thanks to Java with some cool posts. I have got ser and asterisk on the same box, on different IP addresses. In addition to this I am running mediaproxy (I think this will be better than nathelper+rtproxy, simply because of how it can be scaled/split across servers). So far: I can call users from behind a NAT, to others behind the same NAT/different NAT/networks My pstn connection is also routed out from SER, since I dont wish to put the E1 cards into asterisk just yet, so am using asterisk for all my media stuff like voicemail etc. The Problem: When a user is busy I send to voicemail, this is done by using rewrite command in ser.cfg The rewrite happens to a extension configured in extensions.conf in asterisk Asterisk then calls the voice file, looking at logs it does that, and even sends out an email.......BUT.......... I hear no recorded message :-) No I am assuming this is something to do with NAT, since voice problems 9/10 times are. I looked at the mediaproxy logs (/var/log/messages), and the error I got was a warning message: warning: Received packet from a third party xx.yy.yy.yy:18880 last time I had this was because of my network bridge on win XP being enabled The IP address is that of my mediaproxy server. I think it because the voice file is coming from the asterisk server (also on public IP address) and it cannot find the NATted voip client. tks Iqbal