Le 28 oct. 2010 à 07:18, Suresh Krishnan a écrit : >>>> ... >>> I doubt that any new use of the flow label will be backward compatible. Do >>> you have any text about this proposal that I can read up on? >> In my understanding: >> - draft-carpenter-flow-ecmp-03 details a promising particular use of 20-bit >> FLs that wasn't detailed before (Flow Label for tunnel ECMP/LAG) >> - it can work with the current rules about flow-label settings, but too few >> hosts, if any, set FLs to non-zero values today >> - this is, at least in part, due to the fact that these rules are more >> complex that needed: stateful processing is required, or "seems" to be >> required (there is a debate), while algorithmic hashes would be easier to >> implement in hosts and sufficient for load balancing purposes. - >> draft-zhou-softwire-ds-lite-p2p-02 describes a new use of 20-bit FLs >> (Deployment DS-lite in Point-to-Point Access Network) >> - it remains backward compatible with current rules because it is only >> between point-to-point tunnel endpoints, i.e. without relationship with host >> FL settings. >> If one of these proposals would fail with hosts that support current rules >> for FL settings, it couldn't be claimed that they are backward compatible, >> but I have personally identified no such incompatibility. > > The proposals need consenting hosts on both ends to be useful, don't they?
They don't! (Load balancing is a one-way function. If a host sets FLs, its flows to all destinations can be load balanced with ecmp, independently of what other ends do.) >> .... > > My point was, if we need to change the nodes at both ends to implement a new > use of the flow label, the backward compatibility argument is moot. Right "if we need to change the nodes at both ends", but we don't. Regards, RD > Thanks > Suresh > -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
