Purpose of HTTP settings' maxima
Dmitri Tikhonov <dtikhonov@litespeedtech.com> Mon, 01 October 2018 15:42 UTC
Return-Path: <dtikhonov@litespeedtech.com>
X-Original-To: quic@ietfa.amsl.com
Delivered-To: quic@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 8F076130EA5 for <quic@ietfa.amsl.com>; Mon, 1 Oct 2018 08:42:50 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -1.9
X-Spam-Level:
X-Spam-Status: No, score=-1.9 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=litespeedtech-com.20150623.gappssmtp.com
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 9_yRBQaSorJA for <quic@ietfa.amsl.com>; Mon, 1 Oct 2018 08:42:48 -0700 (PDT)
Received: from mail-qt1-x82c.google.com (mail-qt1-x82c.google.com [IPv6:2607:f8b0:4864:20::82c]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 74818130EAF for <quic@ietf.org>; Mon, 1 Oct 2018 08:42:47 -0700 (PDT)
Received: by mail-qt1-x82c.google.com with SMTP id q40-v6so1553357qte.0 for <quic@ietf.org>; Mon, 01 Oct 2018 08:42:47 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=litespeedtech-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:subject:message-id:mail-followup-to:mime-version :content-disposition:user-agent; bh=HoIjcpH0KWCM1kGT9zdLz8MVj9QwZgvfvI+OsWXWfiA=; b=fSkZItT7Do7PE6va7f5gGkU7Hoo3/UmQpghxNhWXQ5K5KfgXXAq7WGYA761oaPbAfN wEGHtrhLYnBrv64qLla68gZUlQJrizglIMru9aBynEkXnWt3xseFGgo8nXvlDFx1ndYW nCZXRWpJyEsN6pSbUdMOY+Fz9fBkClMv+lLWhYnHK5vHg0F6dqKtTwWYl8cfMTsWVIEg REWhl1zM921kyDBvcnF6cwoO9ehd3Ej2gY+6EB5JNWmh3lG/WUDvSmrkq5t1Qi1wGQIg MzcSxM86Ygf422fTWZDzHjVt5iUc/QV0HPkkwb5wX6581UJgG8QEx3qI9XWsiP8IywLY tudw==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:subject:message-id:mail-followup-to :mime-version:content-disposition:user-agent; bh=HoIjcpH0KWCM1kGT9zdLz8MVj9QwZgvfvI+OsWXWfiA=; b=j9zBG66Nwy8N2aS3tikn3JPgzg3ZdUeINdNUt+qdCjM0S/Attf+ApbNXjubcbAs2RI tCjoQA+ZSvkuBcfPuOrBcBCUmWBKxvPLDBtgwpgBLbgjGGN7da5y2dt5JWE06vclZLBx tTCfTDbpi4qPBF9BWyopRtB0g//sTFqNg61L7wHtVxkRZn0aIzZtn9fk2SfBRxoeFcVv qsYMY3hDpzhw7n/tyuLP8CguNfi2xp2FV6N0cwNjMRkwi5MqYu0HWMpQZuDgX/sJeQVc qTEGGOCVXRb0vgkPed16I7w5DfhMVgYfTt664DyBgB3ZJ2lSSGN8i5u7ZIZjFIljXm3m E0Ag==
X-Gm-Message-State: ABuFfogRhL9ONhij6A29sORE5kjJ56uj6sjG+Nh0nn8egc/kt2s/o/8X C5SSZG+GPXikPcbWGd4Lk/wyTJuWs48=
X-Google-Smtp-Source: ACcGV61orrTxv3dWfPS1rbX4yoHTGRne3E+xZXvgJphFAXquH4MSlfKOBN0HKfVAedQidyzWqKz2rg==
X-Received: by 2002:ac8:5508:: with SMTP id j8-v6mr8958802qtq.139.1538408566382; Mon, 01 Oct 2018 08:42:46 -0700 (PDT)
Received: from ubuntu-dmitri (ool-44c1d219.dyn.optonline.net. [68.193.210.25]) by smtp.gmail.com with ESMTPSA id f90-v6sm9970089qkf.49.2018.10.01.08.42.45 for <quic@ietf.org> (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 01 Oct 2018 08:42:45 -0700 (PDT)
Date: Mon, 01 Oct 2018 11:42:43 -0400
From: Dmitri Tikhonov <dtikhonov@litespeedtech.com>
To: IETF QUIC WG <quic@ietf.org>
Subject: Purpose of HTTP settings' maxima
Message-ID: <20181001154242.GB20456@ubuntu-dmitri>
Mail-Followup-To: IETF QUIC WG <quic@ietf.org>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Disposition: inline
User-Agent: Mutt/1.5.24 (2015-08-30)
Archived-At: <https://mailarchive.ietf.org/arch/msg/quic/wXttU3H7M9TAxYJzDVHtzQy_-oQ>
X-BeenThere: quic@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Main mailing list of the IETF QUIC working group <quic.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/quic>, <mailto:quic-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/quic/>
List-Post: <mailto:quic@ietf.org>
List-Help: <mailto:quic-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/quic>, <mailto:quic-request@ietf.org?subject=subscribe>
X-List-Received-Date: Mon, 01 Oct 2018 15:43:05 -0000
Hello,
draft-ietf-quic-http-14 [1] states:
The following settings are defined in HTTP/QUIC:
SETTINGS_NUM_PLACEHOLDERS (0x3): An integer with a maximum value of
2^16 - 1. The value SHOULD be non-zero. The default value is 16.
SETTINGS_MAX_HEADER_LIST_SIZE (0x6): An integer with a maximum value
of 2^30 - 1. The default value is unlimited.
These maximum values seem arbitrary. Assuming that they are, I wonder:
why specify them at all?
Both of these are integers, which means that they must be expressed
using the QUIC integer encoding [2]. That is to say, both have an
implicit limit of 2^62 - 1.
Since both of these specify what the sender is willing to support,
an arbitrary maximum like this is unnecessary. The peer will select a
minimum of its own and the sender's specified maximum. If that happens
to be 2^62 - 1, well, then so be it!
- Dmitri.
1. https://tools.ietf.org/html/draft-ietf-quic-http-14
2. https://tools.ietf.org/html/draft-ietf-quic-transport-14#section-7.1
- Purpose of HTTP settings' maxima Dmitri Tikhonov
- RE: Purpose of HTTP settings' maxima Lucas Pardue