Subject: [OSPF] Jari Arkko's No Objection on draft-ietf-ospf-te-metric-extensions-10: (with COMMENT)

From: "Jari Arkko" <[email-masked]>
Date: Wed, 07 Jan 2015 04:08:43 -0800

Jari Arkko has entered the following ballot position for
draft-ietf-ospf-te-metric-extensions-10: No Objection

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COMMENT:
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Thank you for doing this work. It is very important and I can clearly see
the use cases.

I do have some comments though.

I think it would be useful to specify explicitly what the IEEE floating
point number format variant is being used. I assume binary32. (Also noted
in the Gen-ART review.)

I am a bit surprised by the A bit design. Would it be useful to add some
rationale for why this approach has been taken? As I read the document I
find it difficult to understand why the bit carries extra value for the
receiver. It does signal an exceptional condition, but at the same time,
any real action (e.g., Step B in Section 3) seems to be something that
should be based on the calculation of the actual bandwidths and delays
rather than the flag itself. Or did I misunderstand this?

Also, it would be useful to specify what information must be understood
in the network for the A bit usage. Do all nodes have to the same
understanding of the threshold throughout the network? Or just the
sending node?

Finally, I would have preferred to see some defaults for the various
configurable values, and some discussion of the requirements for the
values. Again, do the measurement period for instance have to be aligned
across a network, or not? A section on management considerations might be
appropriate.