Re: Payload length 0
Ian Swett <ianswett@google.com> Fri, 18 May 2018 12:07 UTC
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From: Ian Swett <ianswett@google.com>
Date: Fri, 18 May 2018 08:06:01 -0400
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Subject: Re: Payload length 0
To: Martin Thomson <martin.thomson@gmail.com>
Cc: Marten Seemann <martenseemann@gmail.com>, IETF QUIC WG <quic@ietf.org>
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I would also prefer to not do either of these, because I think it adds complexity and the byte savings are tiny. On Fri, May 18, 2018 at 1:34 AM Martin Thomson <martin.thomson@gmail.com> wrote: > Having just implemented this (and gotten it wrong once), I don't want more > special cases. Both of these options need extra code. As Kazuho points > out, filling in a two octet length is trivial. > > It's true that a length of 0 is invalid, but so is 1 through 16. > > Yes, this saves an octet, on about 4 packets per connection in the common > case, more like 2 if you actually take advantage of compound packets. > 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. > >
- Payload length 0 Marten Seemann
- Re: Payload length 0 Martin Thomson
- Re: Payload length 0 Ian Swett
- Re: Payload length 0 Dmitri Tikhonov
- RE: Payload length 0 Deval, Manasi
- Re: Payload length 0 Jana Iyengar
- Re: Payload length 0 Christian Huitema
- Re: Payload length 0 Jana Iyengar
- Re: Payload length 0 Christian Huitema
- Re: Payload length 0 Martin Thomson
- Re: Payload length 0 Jana Iyengar
- Re: Payload length 0 Christian Huitema
- Re: Payload length 0 Martin Thomson
- Re: Payload length 0 Jana Iyengar
- Re: Payload length 0 Marten Seemann
- Re: Payload length 0 Eggert, Lars