I have done some benchmarking.. Using pjsip over 3G without a stun server takes about 5 seconds to get registered. If I use a stun server it takes about 9 seconds to register. Also the iPhone 3G network indicator does not spin until after 4 seconds have passed when a stun server is used, without it the network indicator spins straight away when sip client is launched. Any idea why? Im using Pjsip revision 3202 from the svn. Sent from my iPhone