Most of the SIP implementations are handling NAT incorrectly having big difficulties when the system is deployed commercially or they are configured to route all media trough your server which is very inefficient and a big overhead for your network.
With our software you can forget about NAT issues. All our servers and clients have built in superior NAT handling solutions.
Our clients will take the most from the latest NAT handling technologies (RFCs and draft, such as STUN, ICE, etc) and will take out the most from the used platform by using all the NAT traversal related techniques (automatic firewall configuration, UPNP, etc) and our server side software has “intelligent” NAT handling techniques that will save you the most possible bandwidth (by not routing the RTP through your network when it is not necessary) and you will never have clients who are unable to initiate calls or with two-way audio problems.
The server will check not only if the client is behind a nat or not, but also other checks are performed to ensure that you will always have a 2 way audio connection (multiple media path detection, like media forking, last rtp address, etc)
Read more in our blog.