On Thu, 9 Sep 2010, Brian E Carpenter wrote:
If we do agree on this, it's very helpful, because it guides all further decisions. For example, it allows us to see that the label is immutable on a best effort basis, rather than mathematically immutable. So we ccould say both that forwarding nodes MUST NOT change the label, *and* that downstream nodes MUST NOT rely on the value being unchanged.
Last I checked, the standards said that if precedence/dscp changed, the host should reset the session (correct me if I'm wrong, I don't really have time to check it right now).
In real life, ISPs consider DSCP as one thing they have the right to change (along with TTL) in transit. I can imagine the flow label being considered the same thing regardless of what the standard says.
For me, the flow label would be most useful in tunnel scenarios. We have mobile base station controllers which outputs hundreds of megabits/s of tunneled packets and this is all between the same SRC/DST IP. The way 3GPP does things, this is only going to increase. Being able to use flow labels to identify an individual user tunnel and thus being able to hash more efficiently when doing load sharing would be most beneficial.
-- Mikael Abrahamsson email: swm...@swm.pp.se -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
