> Has anybody discussed adding a header with just the 3 bytes you need *before* > the IP header?
Yes. Ever since you proposed pretty much that at a previous IETF meeting, I've been thinking that architecturally it makes a lot of sense to think about ROLL as a sub-IP protocol. > The downside is that you need a new code point (for demux) in the different > layer2s that you want to run this on. And that is exactly the non-starter about the general proposal. It is not acceptable to require a new spec for each of the many link layers we want to run ROLL on, in particular for those who don't really care that much about the overhead. However, it would be pretty easy to put something in 6lowpan to carry those 3 bytes. (Consider it an advanced form of header compression for the 48-byte IP-in-IP thing, if you don't like the sub-IP thinking.) Consult http://tools.ietf.org/html/draft-bormann-6lowpan-ext-hdr-00 for a sample base design. Such a simple extension may actually be a preferable way to carry ROLL in 6lowpan. Gruesse, Carsten -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
