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Re: Design Issue: Frame Size Items

From: Roberto Peon <grmocg@gmail.com>
Date: Tue, 7 May 2013 13:18:46 -0700
Message-ID: <CAP+FsNed0Mw9W10-dd3HeJGLadawvSVo791Hg5SnkDjcOdOZUQ@mail.gmail.com>
To: James M Snell <jasnell@gmail.com>
Cc: Martin Thomson <martin.thomson@gmail.com>, "ietf-http-wg@w3.org" <ietf-http-wg@w3.org>
Works for me.


On Tue, May 7, 2013 at 12:07 PM, James M Snell <jasnell@gmail.com> wrote:

> On Tue, May 7, 2013 at 11:07 AM, Martin Thomson
> <martin.thomson@gmail.com> wrote:
> > On 7 May 2013 08:19, James M Snell <jasnell@gmail.com> wrote:
> >> 1. There is an existing ed note in the draft indicating that we
> >> currently do not have any way of specifying the maximum frame size.
> >> There are several possibilities:
> >>
> >>   a. We decide we don't need to report a maximum frame size.
> >
> > This has been discussed.  The problem is that you have to then FIX the
> > maximum frame size and require that all implementations support that
> > size.  No one can decide on a goldilocks number: 4096, 8192, 16384,
> > 32768 or 65536 have all been variously proposed.  Others want to add
> > extra bits to the length field to open up other options (i.e.,
> > petabytes).
> >
> >>   b. We introduce a MAX_FRAME_SIZE setting for the SETTINGS frame.
> >
> > This introduces another "known state" issue (see Gabriel's issues).
> > You have to have a default (see above), and then a robust way to
> > change.
> >
>
> Option (b) certainly isn't perfect but it works. Since our frame size
> field is expressed as an unsigned 16-bit integer, we already have a
> fixed maximum size (2^16-1 + 8) which ought to be the default
> MAX_FRAME_SIZE. If an implementation needs it to be smaller, they can
> specify so using the SETTINGS.
>
> >>   c. We add a headers block to the RST_FRAME and GOAWAY frames ;-) ..
> >
> > I'm not following you.
> >
>
> I was being silly.. never mind ;-)
>
> >>   I think I prefer option (a) but (b) works too.
> >>
> >> 2. In the current draft we say that all implementations MUST be
> >> capable of supporting frames up to 8192 octets in length. We don't
> >> say, however, whether that size includes the 8-byte header or is that
> >> just payload octets?
> >
> > That's a simple fix.  Toss a coin.  ;)
>
> Ok, coin toss says the 8-byte header is not included. That work for
> everyone?
>
> - James
>
>
Received on Tuesday, 7 May 2013 20:19:13 UTC

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