Hello List, In my fierce battle to overcome the NAT problem I have now running SER and Mediaproxy without any problem. Whenever any Nated EP like to call to PSTN or a non nated EP the call goes ok. Whenever I try to call from a non nated EP to a NATed EP the call does not go through. It seems like that the destination address is not known by mediaproxy so it can't forward the call to the correct EP. My question is whether this problem might be caused by my ser.cfg or that this is typical SIP behaviour. In other words is it possible to call to any EP that is behind Symmetric NAT. Kindest Regards, Tjapko Smits --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.693 / Virus Database: 454 - Release Date: 31/05/2004 _______________________________________________ Serusers mailing list serusers(a)lists.iptel.org http://lists.iptel.org/mailman/listinfo/serusers