Re: Flow label versus Extension header - protocol itself

[Francis Dupont <Francis.Dupont@enst-bretagne.fr>]

I am in favor of a destination option (don't add a new extension header,
PLEASE!) because it seems a tag which can be used (and only the tag itself)
for demultiplexing can be needed. IPsec has something very similar named
an SPI and the simple constraint for SPIs to be usable for demultiplexing
bt the receiver is they have to be assigned by the receiver.
This is clearly impossible for a standard flow label so the shim tag should
be assigned (the whole tag or a part of the tag) by the receiver in the
initial shim negociation phase. IMHO the IKE SPI procedure should be
copied as it...
The extra cost of a destination option should not be a problem if the option
is needed only in special cases (i.e., not in every packets).

Regards

Francis.Dupont@enst-bretagne.fr

PS: even this is hard to implement, usually flow labels are from a
pseudo-random generator and uniqueness is not checked.