Re: [tcpm] I-D Action: draft-nishida-tcpm-agg-syn-ext-01.txt

[Carles Gomez Montenegro <[e-mail]>]

Hi Yoshi,

Thanks for your response.

There are currently 22 option Kind numbers assigned by IANA (that are
not obsoleted or temporary). There are also 14 ExID values assigned.

A conservative approach would need to consider all possible
combinations. It seems that this approach would require a 3-bit GID.

However, probably only a (small?) subset of the possible TCP options
would be used simultaneously, and therefore a 2-bit GID would appear
to suffice.

Would this make sense?

Cheers,

Carles




> Hi Carles,
> Thanks for the feedback.
> Yes, that's the point I have been wondering about.
> I agree with your assessments. Do you have any thoughts on the best choice among them?
> --
> Yoshi
>
>
> On Mon, Nov 7, 2022 at 2:06 AM Carles Gomez Montenegro <[e-mail]> wrote:
>>
>> Hi Yoshi,
>>
>> Thanks for your draft, and for taking into account the needs of a new
>> experimental proposal such as the TARR option.
>>
>> Indeed, currently, 4 bytes is the minimum format size to announce
>> support of an RFC 6994-conforming experimental TCP option. However, as
>> you mention in your draft, the same information might be conveyed by
>> using less bits.
>>
>> I've been thinking about whether the number of GID bits (i.e., 2 bits)
>> is the best choice or not. My own conclusion is that it is, since:
>>
>> - Number of GID bits = 0 --> it does not allow to omit unused aggregated blocks.
>> - Number of GID bits = 1 --> it would support only 14 options.
>> - Number of GID bits = 3 --> it would support 40 options, which
>> perhaps is not really necessary, and would add one bit of overhead per
>> aggregated block.
>>
>> Thanks,
>>
>> Carles
>>
>>
>>
>>
>>
>> > Hi folks,
>> >
>> > I have submitted an updated version for aggregated option draft.
>> > The main points of this version are the following, mainly to address Joe's comments.
>> > - The draft contains now aggregated option only.  delay negotiation proposal has been removed and out of scope of the draft.
>> > - The main target for aggregated option is a new experimental proposal such as TARR option while It is possible to aggregate existing options with some conditions,
>> > It would be great if you could provide some feedback.
>> >
>> > Thanks,
>> > --
>> > Yoshi
>> >
>> >
>> > On Sun, Oct 23, 2022 at 12:15 AM <[e-mail]> wrote:
>> >>
>> >>
>> >> A New Internet-Draft is available from the on-line Internet-Drafts directories.
>> >>
>> >>
>> >>         Title           : Aggregated Option for SYN Option Space Extension
>> >>         Author          : Yoshifumi Nishida
>> >>   Filename        : draft-nishida-tcpm-agg-syn-ext-01.txt
>> >>   Pages           : 9
>> >>   Date            : 2022-10-23
>> >>
>> >> Abstract:
>> >>    TCP option space is scarce resource as its max length is limited to
>> >>    40 bytes.  This limitation becomes more significant in SYN segments
>> >>    as all options used in a connection should be exchanged during SYN
>> >>    negotiations.  This document proposes a new SYN option negotiation
>> >>    scheme that can aggregate multiple TCP options in SYN segments into a
>> >>    single option so that more options can be negotiate during 3 way
>> >>    handshake.  With its simple design, the approach does not require
>> >>    fundamental changes in TCP.
>> >>
>> >>
>> >> The IETF datatracker status page for this draft is:
>> >> https://datatracker.ietf.org/doc/draft-nishida-tcpm-agg-syn-ext/
>> >>
>> >> There is also an HTML version available at:
>> >> https://www.ietf.org/archive/id/draft-nishida-tcpm-agg-syn-ext-01.html
>> >>
>> >> A diff from the previous version is available at:
>> >> https://www.ietf.org/rfcdiff?url2=draft-nishida-tcpm-agg-syn-ext-01
>> >>
>> >>
>> >> Internet-Drafts are also available by rsync at rsync.ietf.org::internet-drafts
>> >>
>> >>
>> >> _______________________________________________
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>> >> or ftp://ftp.ietf.org/ietf/1shadow-sites.txt
>> >
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