I'd rather see the IPv6 in UDP protocol be defined as that is not included in a draft as it is not documented in any of the old nor in the new draft (draft-blanchet-v6ops-tunnelbroker-tsp-00) and I think that it is an interesting thing to have as many of those so called "NAT-routers" don't support proto-41 forwarding but do allow forwarding of udp packets on a certain port. This is basically one of the things that Teredo addresses but that uses a completely different model and also has signalling included. The TSPC 1.0 sources provided through the Freenet6 site don't mention anything about these UDP tunnels either. Having a standard for these would be a good thing as then the OS's could be made to support it also and afaik there is no such support yet. Maybe the above is going to be addressed for -01? PS: Marc, use 2001:db8::/32 and 192.0.2.0/24 in examples.