Re: [quicwg/base-drafts] Are Separate Uni and Bidi Stream Limits Meaningful? (#2358)

Martin Thomson <> Tue, 22 January 2019 21:48 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id CB04C13114E for <>; Tue, 22 Jan 2019 13:48:57 -0800 (PST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -7.553
X-Spam-Status: No, score=-7.553 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIMWL_WL_HIGH=-4.553, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HTML_MESSAGE=0.001, MAILING_LIST_MULTI=-1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: (amavisd-new); dkim=pass (1024-bit key)
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id 8YplLPTdSRb7 for <>; Tue, 22 Jan 2019 13:48:55 -0800 (PST)
Received: from ( []) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by (Postfix) with ESMTPS id C524D13114A for <>; Tue, 22 Jan 2019 13:48:54 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed;; h=from:reply-to:to:cc:in-reply-to:references:subject:mime-version:content-type:content-transfer-encoding:list-id:list-archive:list-post:list-unsubscribe; s=s20150108; bh=frmkhutZEe/FIEpg/NGdCwrXud0=; b=px7wyGW6MTQGKy6j hUzxdxfXPV++Wf/3tdKjpaD+njTE8U91ophKtQpZ4EGOQSYRtdOn75IqXpSb5j04 fEKXJOvzAtCzt3oqUYdMFDHJO/CMrJpHPGw2Ak3ws2QmYT9QMb4qGRFtCOfJEMGJ oBHKW9Kq8jnhR54JUhfDQEYe3IM=
Received: by with SMTP id filter1487p1mdw1-5657-5C478FC5-31 2019-01-22 21:48:53.827418996 +0000 UTC m=+682808.291542658
Received: from (unknown []) by (SG) with ESMTP id fTt3-PqRQr2VZPQcknr3Vg for <>; Tue, 22 Jan 2019 21:48:53.788 +0000 (UTC)
Received: from (localhost []) by (Postfix) with ESMTP id BC48E3E0852 for <>; Tue, 22 Jan 2019 13:48:53 -0800 (PST)
Date: Tue, 22 Jan 2019 21:48:53 +0000
From: Martin Thomson <>
Reply-To: quicwg/base-drafts <>
To: quicwg/base-drafts <>
Cc: Subscribed <>
Message-ID: <quicwg/base-drafts/issues/2358/>
In-Reply-To: <quicwg/base-drafts/issues/>
References: <quicwg/base-drafts/issues/>
Subject: Re: [quicwg/base-drafts] Are Separate Uni and Bidi Stream Limits Meaningful? (#2358)
Mime-Version: 1.0
Content-Type: multipart/alternative; boundary="--==_mimepart_5c478fc5bae7e_14403fc50d2d45bc730a0"; charset="UTF-8"
Content-Transfer-Encoding: 7bit
Precedence: list
X-GitHub-Sender: martinthomson
X-GitHub-Recipient: quic-issues
X-GitHub-Reason: subscribed
X-Auto-Response-Suppress: All
X-SG-EID: l64QuQ2uJCcEyUykJbxN122A6QRmEpucztpreh3Pak00cuIUadYy3D5l1VgadNlCyFkjMWZrsbwgYr PXrC84z4oVvuhZuh7IGMos3qHJzLB4Ngwx4hVR8s00V4N2t27x/gGrzgXkrbFepdi11iwdy5/k35ui cSJuzlSfgfKW6oWar49IZEj8aYZuJ5CgAz6tGpwF2u0MvWQb2Qu2nacby7TXBpua8FFvMdgXsXVb7M U=
Archived-At: <>
X-Mailman-Version: 2.1.29
List-Id: Notification list for GitHub issues related to the QUIC WG <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Tue, 22 Jan 2019 21:48:58 -0000

Though functionally a bidirectional stream with accompanying STOP_SENDING looks like a unidirectional stream, it is unlikely that an application protocol will treat it as being unidirectional, because the type of stream is input to processing - bidirectional streams have different semantics.  So I think that we *can* rely on application protocols dealing with this case properly.

But the split has utility.  At least in h3, this avoids the problem @LPardue describes.  Firefox treats responses to requests and pushes very differently from a flow control perspective and the split there makes things considerably more efficient for us.  MAX_PUSH_ID is insufficient - we want that to be much higher than the number of concurrent unidirectional streams so that we can learn about potential pushes.  The actual limit needs to be lower, particular since the utility of push is... questionable.

I can only speculate about other protocols, but I think that we have enough justification here to keep the design as-is.

You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub: