On the surface the migration from IPv4 to IPv6 looks like it could solve the NAT traversal problem for developers of VoIP or IP based video chat services. IPv6 does away with the scarcity of IP addresses that NAT addresses, so without the problem, are NATs even required post IPv4?
It depends who you’re asking. It’s true NAT for address conservation will be less of a concern as IPv6 rolls out, but there seem to be a few reasons why NATs may persist.
Topology hiding is one benefit of NAT in an IPv4 network. Advocates of IPv6 state that topology hiding via NAT is unnecessary with IPv6, but until things like NPT and stateful inspection are ubiquitous on CPE there will be a need for NAT. Industry is having many discussions on NAT, network security, and how CPE (router/firewall) manufactures could provide protection in an IPv6 world, some of which can be found here:
For the foreseeable future, developers of real-time applications and services like VoIP and video chat will not get around the persistant problems associated with running these types of services through NATs and firewalls.