I’m having difficulties with this setup, and am not even sure it is possible.
My asterisk server lives behind a NAT modem/router and is registering successfully to my SIP provider. I’ve done it using dyndns combined with the extenhost directive in sip.conf.
However, I want my asterisk server to be reached by clients who happen to be in another part of the world and are themselves behind another nat modem/router. So I figured, if I could let these clients all register to my asterisk server, then I would be able to route calls coming on the central sip number, which my asterisk server can pick up just fine, to their sip client no matter where they are in the world.
Then if that works I would purchase hard phones for all my clients.
The problem I have is that everyone says how sip was not designed with nat in mind and that iax2 is better, but then again even softphones speaking iax2 are hard to find as are hardphones.
Then some people say I would need a sipproxy between my asterisk server and the voip clients scattered all around the world.
Does anyone here had success with this kind of setup, asterisk server bind nat and phones behind other nat? How was this accomplished? What special kind of hardware should I purchase?
I’m rather free in my choices because I can influence all three locations (New York, The Netherlands and South-America) so even putting three asterisk servers there would be an option.
Thanks in advanced
PS I’m using a standard i386 machine running openbsd 4.2 with asterisk 1.2.22