> But routers — including ISP gateway routers — insist on doing NAT not only for IPv4, but also for IPv6 (using the fe80:: prefix.) So on any regular home or of

> But routers — including ISP gateway routers — insist on doing NAT not only for IPv4, but also for IPv6 (using the fe80:: prefix.) So on any regular home or office network, devices are going to acquire private-use IPv4 and IPv6 addresses. Maybe I'm misunderstanding your comment, but fe80:: is a link-local address and used by devices to talk to each other on the network. It's there by default when IPv6 is enabled. Most ISPs that support IPv6 will provide a /56 to the router, and then the router will assign a /64 to wifi. Then the clients get an IPv6 address using DHCPv6 or a route announcement. Unfortunately most VoIP providers do not support IPv6. voip.ms, which I use, for example, does not. In my Asterisk pjsip configuration, I use: external_media_address = dyn.example.org external_signaling_address = dyn.example.org where dyn.example.org is a dyndns that I use that points to my home Asterisk server, on a dynamic IPv4 address. My ISP does change my IPv4 address rather often, and sometimes I have to restart asterisk for the change to be effective.