I'd go with that so long as we can keep it fast. Remember we can be
taking 45Mbit video streams off an mbone tunnel. We should I feel
make sure the one layer deep IPIP is optimised and the other cases
are assumed to be slow.
It's going to be one extra comparison in the common case, don't worry,
and it is going to be faster in the common cases for other reasons.
I assume Dave you are moving towards a SGI like solution ?
Partially...