Re: [conex] draft-ietf-conex-destopt-01.txt

Hi John,

first of all: I added some text to this draft about how exactly the ConEx bits 
need to be interpreted and which kind of packets should/can have which 
markings, because there is some more specific text need in this draft. What 
every is written there is of cause open for discussion. So thanks for your 
feedback so far.

Now to your point: The idea behind the MUST below was that a network node can 
figure out based on just one packet if the connection is ConEx-capable or not 
even though the packet itself might not have any ConEx bit set. I'm not sure 
if this is requirement. If not it might be unnecessary overhead and we could 
remove this. If we remove this we don't need the X bit neither anymore. But 
in fact I believe most packets will still need to have a CDO (except pure 
ACKs...?).

Another good point is, if it is possible to have one half-connection 
ConEx-enable and the other not? Maybe it might make sense if e.g. use data 
only flow in one direction and the other direction which sends only pure ACKs 
is not ConEx-capable...? Don't no... further options here?

Mirja 

On Monday 07 November 2011 17:01:35 John Leslie wrote:
> internet-drafts@ietf.org <internet-drafts@ietf.org> wrote:
> > http://www.ietf.org/internet-drafts/draft-ietf-conex-destopt-01.txt
>
>    The changes are all additions at the end of Section 4.
>
>    In this post, I ask for clarification of the first added sentence:
> ]
> ] All packets of a ConEx-capable connection MUST carry the CDO.
>
>    I'm guessing the intention is that "all packets" must include this
> ConEx Destination Option. But I don't want to venture too far before
> getting a yes or no...
>
>    Also, we should clarify whether we mean "in both directions".
>
>    Perhaps we should even clarify when we start counting "all".
> (Presumably not the first ACK of SYN-ACK; what about the second?)
>
>    Regardless, I'll venture so far as to ask "Why should _all_ packets
> carry this option?" I'd like to see a _lot_ more justification for
> adding this much overhead.
>
> --
> John Leslie <john@jlc.net>
> _______________________________________________
> conex mailing list
> conex@ietf.org
> https://www.ietf.org/mailman/listinfo/conex

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Dipl.-Ing. Mirja Kühlewind
Institute of Communication Networks and Computer Engineering (IKR)
University of Stuttgart, Germany
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email: mirja.kuehlewind@ikr.uni-stuttgart.de
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