Re: draft-ietf-quic-http-29, "1.1. Prior versions of HTTP"

Mark Nottingham <> Thu, 18 June 2020 23:19 UTC

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Subject: Re: draft-ietf-quic-http-29, "1.1. Prior versions of HTTP"
From: Mark Nottingham <>
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Date: Fri, 19 Jun 2020 09:19:48 +1000
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To: "Julian F. Reschke" <>
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My .02 -

I think we need to balance between being correct and over-complicating the text here. In *theory*, Julian is correct; in wide practice, pipelining isn't used because of the limitations it has, as well as implementation / interop issues.

How about something like:

"Because of limitations in how HTTP exchanges are mapped onto TCP connections in HTTP/1.1, multiple parallel connections are often used..."



> On 12 Jun 2020, at 9:48 pm, Julian Reschke <> wrote:
>> HTTP/1.1 [HTTP11] is a TCP mapping which uses whitespace-delimited text fields to convey HTTP messages. While these exchanges are human-readable, using whitespace for message formatting leads to parsing complexity and motivates tolerance of variant behavior. Because each connection can transfer only a single HTTP request or response at a time in each direction, multiple parallel TCP connections are often used, reducing the ability of the congestion controller to effectively manage traffic between endpoints.
> Isn't that a bit misleading, as at least in theory HTTP/1.1 supports
> pipelining?
> BEst regards, Julian

Mark Nottingham