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Constant priotrity (Was: SYN_REPLY)

From: Yoav Nir <ynir@checkpoint.com>
Date: Fri, 22 Feb 2013 09:44:17 +0000
To: Roberto Peon <grmocg@gmail.com>
CC: HTTP Working Group <ietf-http-wg@w3.org>
Message-ID: <D541DC8A-61CB-4E08-9478-AD3DC60E05E8@checkpoint.com>

On Feb 22, 2013, at 2:38 AM, Roberto Peon <grmocg@gmail.com> wrote:

> Browsers are *extremely* likely to use this, and they're where we're most bandwidth constrained.
> The goal is to allow the browsers to emit requests as soon as they're encountered.

Hi Roberto

should resources have the same priority throughout their transmission?  Some resources, such as images and maybe music/video, we'd like to get the start of early on.

All image formats that I know of have the image dimensions at the beginning. So if you have a tag like <img src=""> the browser has no idea how much room to leave for the image. So with some sites you get some initial rendering, and then the page elements begin moving all over the place, adjusting to the actual size of the image, even before most of the image is displayed. I think it should be our goal to minimize this "moving around" time. OTOH we don't want images to have the highest priority in general.

Perhaps it would help to have the browser specify an "initial boost" for the resource, so that the first X bytes (X determined by the server) are sent with very high priority, afterwards dropping to their regular priority as specified by the client. This can't be done with a subsequent PRIORITY, because X should be small relative to the amount of data the server manages to send within a round-trip time.

What do you think?

Yoav
Received on Friday, 22 February 2013 09:44:47 GMT

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