NAT on our Voiceless platform does work in many cases. However, due to the nature of NAT, and the numerous implementation and 'fixes' and 'bodges' in routers, it can be tricky to get working. Lots of the phones that we've tested do just work without the need for an ALG, Stun, Port Forwarding etc, but other network equipment (ie the router) may get in the way.
We'd always suggest using public IP addresses for VoIP devices.
If you do want to use NAT, then here are some tips if you are struggling:
- Disable UPnP on routers
- Disable SIP ALG on the router (or try enabling)
- Disable Stun settings on the VoIP phone (or try enabling it - stun.aa.net.uk can be used)
If NAT works, then well done, but if not we cannot guarantee to be able to make it work. We can provide broadband lines with constant quality monitoring and public IPs that can be used for VoIP - even multiple lines through different back-haul suppliers for extra resilience. Do speak to us.
Further information: http://aa.net.uk/kb-telecoms-sipnat.html