Re: [quicwg/base-drafts] Allow not creating QPACK codec streams (#2529)

Dmitri Tikhonov <> Wed, 20 March 2019 18:46 UTC

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Date: Wed, 20 Mar 2019 18:46:20 +0000
From: Dmitri Tikhonov <>
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Subject: Re: [quicwg/base-drafts] Allow not creating QPACK codec streams (#2529)
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dtikhonov commented on this pull request.

>  HTTP_WRONG_STREAM_COUNT. These streams MUST NOT be closed. Closure of either
 unidirectional stream type MUST be treated as a connection error of type
+An endpoint MAY avoid creating its own encoder stream if the maximum size of
+the dynamic table permitted by the peer is zero.
+An endpoint MAY avoid creating its own decoder stream if the maximum size of
+its own dynamic table is zero.
+An endpoint MUST allow its peer to create both encoder and decoder streams

> Hmmm, I think I was reading #2100 (comment) wrong.
> But yeah, the **intention there was to disallow setting the uni streams limit to less than 3** in order to allow the other side to open all of their streams.

(Emphasis added)

I see how you get that from that comment by @MikeBishop:

> Discussed in Tokyo; do not require creating the streams, but creating them is not forbidden even if the setting prevents their use

But the "setting" refers to the QPACK settings -- namely, the size of the dynamic table -- and not to the stream limits.  Otherwise, how could it not be forbidden to create streams over the stream number limits specified by the peer?

I agree that more clarity is required.  My preference would be to allow the unidirectional stream limit to be set to 1 to allow just the HTTP Control Stream.

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