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From: Jana Iyengar <jri.ietf@gmail.com>
Date: Fri, 25 May 2018 15:50:56 -0700
Message-ID: <CACpbDcezAWLC+4W8CezXnjyivWGV6ktR_XoCDnBT24MUKCg-PA@mail.gmail.com>
Subject: Re: Payload length 0
To: Martin Thomson <martin.thomson@gmail.com>
Cc: Marten Seemann <martenseemann@gmail.com>, QUIC WG <quic@ietf.org>, 
 "Eggert, Lars" <lars@netapp.com>
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I'm fine with having 0 not be special. Marten and Lars had stronger
opinions, so they should speak up.

On Thu, May 24, 2018 at 9:06 PM, Martin Thomson <martin.thomson@gmail.com>
wrote:

> It seems like the discussion has settled down.
>
> For those advocating for 0 being special, are you happy to keep things as
> they are?
> On Fri, May 18, 2018 at 3:08 PM Marten Seemann <martenseemann@gmail.com>
> wrote:
>
> > Jana asked me to raise this issue on the list, after we already had a bit
> of discussion in https://github.com/quicwg/base-drafts/pull/1301.
>
> > The proposal is to make a payload length of 0 a special value, indicating
> that the packet is not a coalesced packet, i.e. that the whole payload of
> the UDP packet is the QUIC packet. This would eliminate an invalid value of
> the payload length (there are no empty packets), save one byte for packet
> lengths where varint encoding would result in a two byte number, and
> apparently also simplify (some) implementations.
>
> > Kazuho argued creating two versions of each Long Header type (one with
> and one without a payload length) is the better solution, since all values
> below the AEAD tag length + 1 are invalid values anyway, and it would save
> one more byte.
>
> > We should make a decision if and what we want to do about this.
>
>

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<div dir=3D"ltr">I&#39;m fine with having 0 not be special. Marten and Lars=
 had stronger opinions, so they should speak up.</div><div class=3D"gmail_e=
xtra"><br><div class=3D"gmail_quote">On Thu, May 24, 2018 at 9:06 PM, Marti=
n Thomson <span dir=3D"ltr">&lt;<a href=3D"mailto:martin.thomson@gmail.com"=
 target=3D"_blank">martin.thomson@gmail.com</a>&gt;</span> wrote:<br><block=
quote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc=
 solid;padding-left:1ex">It seems like the discussion has settled down.<br>
<br>
For those advocating for 0 being special, are you happy to keep things as<b=
r>
they are?<br>
<span class=3D"im HOEnZb">On Fri, May 18, 2018 at 3:08 PM Marten Seemann &l=
t;<a href=3D"mailto:martenseemann@gmail.com">martenseemann@gmail.com</a>&gt=
;<br>
wrote:<br>
<br>
</span><div class=3D"HOEnZb"><div class=3D"h5">&gt; Jana asked me to raise =
this issue on the list, after we already had a bit<br>
of discussion in <a href=3D"https://github.com/quicwg/base-drafts/pull/1301=
" rel=3D"noreferrer" target=3D"_blank">https://github.com/quicwg/<wbr>base-=
drafts/pull/1301</a>.<br>
<br>
&gt; The proposal is to make a payload length of 0 a special value, indicat=
ing<br>
that the packet is not a coalesced packet, i.e. that the whole payload of<b=
r>
the UDP packet is the QUIC packet. This would eliminate an invalid value of=
<br>
the payload length (there are no empty packets), save one byte for packet<b=
r>
lengths where varint encoding would result in a two byte number, and<br>
apparently also simplify (some) implementations.<br>
<br>
&gt; Kazuho argued creating two versions of each Long Header type (one with=
<br>
and one without a payload length) is the better solution, since all values<=
br>
below the AEAD tag length + 1 are invalid values anyway, and it would save<=
br>
one more byte.<br>
<br>
&gt; We should make a decision if and what we want to do about this.<br>
<br>
</div></div></blockquote></div><br></div>

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