> If the singalling protocols would allow for something like 'hi - my client $foo wants to talk to your client $bar. Please direct your response to me' and the

> If the singalling protocols would allow for something like 'hi - my client $foo wants to talk to your client $bar. Please direct your response to me' and the other end would then send the packets with 'this is a packet from my client $bar to your client $foo - as you told me, I'm sending it to you' That's called routing, and routers are perfectly able to do that already, much better than some possibly whacky custom application level implementation. By your reasoning, there's no reason not to have HTTP proxies everywhere. > I don't have to concern myself with configuring a firewall in order to ensure that it doesn't turn into an involuntary fax machine for example This has to be the most ludicrous example I keep hearing again and again. I don't see what's different from the end-user point of view between "my gateway does NAT" vs "my gateway refuses unrelated incoming packets". Seriously, take your random Airport Extreme and it's one freaking checkbox in the IPv6 tab (which should and will, in the forecoming wide availability case, be on by default, just like current NAT). Can we stop conflating NAT with the no-incoming filtering rule already, please? Let's look at the "hello, world" of Linux NATs example: /sbin/iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE /sbin/iptables -A FORWARD -i eth0 -o eth1 -m state --state RELATED,ESTABLISHED -j ACCEPT /sbin/iptables -A FORWARD -i eth1 -o eth0 -j ACCEPT First line is NAT and protects you from nothing by itself. It only happens that usually, the WAN side can't access the LAN side because LAN is on a non-wide routable IP range so packets may simply not be routed. And guess what, second and third line which do filtering, do not require NAT, and are perfectly available features on IPv6.