>A host in the Internet that wants to talk to a host in China would require an >update to parse new DNS double-A (realm, address) records to encapsulate the p >acket IP-in-IP, outer src= 240.0.0.1 outer dest=240.0.0.2. The router that ser >ves the shaft at level 1 attracts 240.0.0.0/8 within realm 1 and routes up the > elevator for more specific (host) routes within that prefix. The router that >serves the shaft at level 2 attracts 240.0.0.2/32 inside the shaft; upon the s >aid packet it would swap the inner and outer destination and the packet would >reach the Chinese address with classical routing within realm 2. > >Routers serving the shaft need an update, but then, only those do. Obviously t >he host in China can only reply if its stack is updated to understand the form >at. But all the other hosts and routers in China can be classical IPv4 as we k >now them long as their traffic stays in China. To migrate to IPv6 what you can > do is map the elevator shaft prefix in, say, 400::/3 (sadly cannot use F00/3 >that would map 240 neatly but is already assigned). > >The current internet would own 400:1::/32, China would own 400:2::/32, etc... >You encode the double-A of the host in the prefix, reserve a well known suffix > for IPv4 mapped double-A, and you have an IPv6 address that can be mapped bot >h ways statelessly. When migrating to v6, each IPv4 node that owns a public IP >v4 address in one realm gets a full IPv6 /64 for free. >"
Somehow this sounds a lot like 6to4: packets get routed to special devices in the network and ISPs have little control over this. Not a popular architecture. Or another way to look at it is the resemblance with the ill fated 'Provider-Based Global Unicast Addresses' (RFC 1884, Section 2.4.7). This was not very popular either.
