I would be reluctant to advocate use of a hash algorithm as computationally expensive as MD5() for generating an IPv6 Flow Label.
My sense is that a thoughtful implementer likely would choose the least computationally expensive algorithm that would suffice to generate a Flow Label value suitable for load-balancing purposes. As a use case, one might consider some sort of content server with very large numbers of short-lived TCP sessions. If an expensive algorithm (e.g. MD5()) were used in that case, then the effort to compute the flow label might be am interesting fraction of "new TCP session creation" overhead. In turn, this might impair the scalability of that content server. In any event, I'm quite comfortable with Brian's current approach to document a possible algorithm that ought to suffice without mandating any particular algorithm. This really is a situation where the details are best left to implementers (since no interoperability issue would arise from different implementations using different algorithms). Yours, Ran -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
