Re: [spring] [Tsv-art] TSV-ART review of draft-ietf-spring-segment-routing-msdc-08

[Alvaro Retana <[e-mail]>]

On October 29, 2018 at 11:34:13 AM, Mirja Kuehlewind (IETF) (
[e-mail]) wrote:

Hi!

FWIW, I agree with Mirja and her proposal below.  Not only does it sound
like this Informational document is talking about items that should be out
of scope, but the first paragraph in §7 says that it talks about "how the
problems described above (in section 3) could be solved using the segment
routing concept.”  To me, these are examples and (as the text also
mentions) "only parts of the solution”.

Let’s please wrap this document up!

Thanks!

Alvaro.


this still sounds very much like inventing a new mechanism which seem a bit
out of scope for this document. However, after all bandwidth requirements
might not be known or are very dynamic because of congestion control or
adaption mechanism in the application (e.g. adaptive video traffic), and
therefore there it is still the same problem that it is no reasonable to
make decision based on this very dynamic metric.

The text below sounds like you are rather interested to a) distinguish
elephant from mice flows and b) understand if the elephant flow has a
maximum bandwidth cap (because it's application-limited). These are
different information and might be more useful for your case. However, I
still think having this discussion in this level of details goes beyond the
scope of the document.

What’s about just saying something like, a central host can collect
per-flow information, either from the host directly or measurement on the
path, and use this information to impact routing. I would, however, also
like to see a note/warning in this context that metrics that are changing
very dynamically should not be used as input for routing decisions.