Subject: [manet] SMF review (short version)

From: Ulrich Herberg <[email-masked]>
Date: Sat, 31 Jul 2010 13:49:21 +0200

Hi,

I have tried to send a review of SMF to the list on Friday, but the
mail is too large. The chairs told me that they would consider
increasing the file size limit of the mailing list, which I think is a
very good idea.

Until then, you can find the full review on:
http://www.herberg.name/SMF_review.txt

Overall comments:
  - The document needs several editorial changes (see full review).
  - It could be made more explicit whether/how mixing different relay
algorithms within the same MANET could interoperate. In particular,
the address block TLVs for indicating different relay mechanisms may
need more explanation. What does a router do when it has several
neighbors with different relay algorithms, and each of them
advertising several 2-hop neighbors with different relay mechanisms.
How should a router select its relays then?
  - It could be made more explicit how SMF operates when using several
interfaces. (e.g., when using different relay mechanisms on each of
the interfaces)
  - I wonder how SMF can work with IPv4 traffic without any particular
header (such as IPSec) to differentiate datagrams. In particular if an
applications sends equivalent datagrams multiple times in a short
interval (e.g. beacons). Henning had the idea of adding transparently
an IP Timestamp header on the originator of an IPv4 packet (e.g. using
netfilter_queue). This, together with the hash of the datagram, should
suffice to avoid wrong duplicate suppression, at least within more
than a millisecond. I think that this could be added to the H-DPD
description of the draft.
  - It could be made more explicit how long DPD entries are stored on a router.

Ulrich