Re: [quicwg/base-drafts] Why is SETTINGS parameter duplication a connection error? (#2663)

Mike Bishop <> Wed, 01 May 2019 21:22 UTC

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Date: Wed, 01 May 2019 21:22:02 +0000 (UTC)
From: Mike Bishop <>
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Subject: Re: [quicwg/base-drafts] Why is SETTINGS parameter duplication a connection error? (#2663)
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In HTTP/2, when SETTINGS can arrive at any time and update anything, the value of a particular setting evolves over time.  You have to be able to handle a setting wandering over the course of a connection, and so having it happen over the course of frame processing isn't actually any different.

In HTTP/3, settings have an initial value before SETTINGS is received, then they get a value once and it's permanent.  You can either mandate that senders construct a "proper" frame, or specify how receivers squash an improper frame; the end result has to be the same, that a setting gets a value once and can't change thereafter.

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