Hi Iljitsch, Le 8 sept. 2010 à 10:44, Iljitsch van Beijnum a écrit : > ... > There is work going on on creating "multipath TCP" where a TCP flow is split > into subflows which take different paths. (See the MPTCP wg.) Currently, it > is assumed that the paths are defined by the source/destination address > pairs, but there are many paths that can't be selected this way.
Subflows of MPTCP have different 5-tuples. They should be treated as different flows as far as load balancing is concerned. > A different way to do this would be to have a path selector value in packets > which the MPTCP (or other multipath transport) can use to tell routers to use > different paths for different subflows. The flow label would be a very good > choice for this, it would then bascially be a "subflow label". > > Considering the above, in my opinion: > > - we shouldn't lock down the flow label such that only one flow label per > flow is allowed because this would impede future innovation This shows the need to define what is meant by "flow" independently in EACH context. For load balancing, what is key is that: - packets of a FL flow should be forwarded without changing their original order (subject to best effort) - packets of different FL flows may have their order freely modified within the network. If MPTCP people would have considered one "meta-flow" comprising several "flows", there would have been little risk of confusion between MPTCP flows and FL flows. But the fact is that than they talk about one "flow" comprising several "subflows". Then an MPTCP subflow is a FL flow. RD -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
