[DNA] Feedback on draft-ietf-dna-cpl-00.txt

[Christian Vogt <chvogt@tm.uka.de>]

Hi JinHyeock, hi Erik,

I took a look at the Complete Prefix List proposal.

First of all, I like the idea of not having to change any entities in 
the network but only the MN's stack.  This is a significant advantage in 
terms of applicability until more radical DNA techniques establish 
themselves.

On thing concerning reliance on unsolicited RAs.  Section 3.1 says:

    ++++
    The host forms the prefix list at any attachment point, that is, this
    process starts independently of any movement.  Though the procedure
    may take some time, that doesn't matter unless the host moves very
    fast.  A host can generate the complete prefix list with reasonable
    certainty if it remains attached to a link sufficiently long.  It
    will take approximately 12 seconds, when it actively perform 3 RS/ RA
    exchanges.  If it passively relies on unsolicited RA messages
    instead, it may take much more time.
    ++++

I see that one cannot really do much analysis for routers that send 
unsolicited RAs every 30ms to 70ms as proposed by RFC 3775 (because such 
RA might not have all of the prefixes included).  But since this high 
frequency would obviously improve the situation for CPL, it might be 
worthwhile to put a note into the draft.

I presume you are planning to do, or have already done, some 
experimental tests to find out how well CPL works when MNs move really 
fast.  Well, maybe this can be done on a theoretic basis like the 
Performance Analysis in section 9.

I do understand that CPL is 100% reliable, even in high-speed scenarios, 
when the prefix sets in RAs from the same link are guaranteed to overlap.

The draft is on its way to Proposed Standard, right?

Kind regards,
- Christian

-- 
Christian Vogt, Institute of Telematics, University of Karlsruhe
www.tm.uka.de/~chvogt/pubkey/