From nobody Mon Oct 12 09:32:01 2020 Return-Path: X-Original-To: hls-interest@ietfa.amsl.com Delivered-To: hls-interest@ietfa.amsl.com Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id C5B9F3A1573 for ; Mon, 12 Oct 2020 09:31:59 -0700 (PDT) X-Virus-Scanned: amavisd-new at amsl.com X-Spam-Flag: NO X-Spam-Score: -3.297 X-Spam-Level: X-Spam-Status: No, score=-3.297 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.2, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, HTML_MESSAGE=0.001, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, 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=apple.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 coy-ttocHWPi for ; Mon, 12 Oct 2020 09:31:58 -0700 (PDT) Received: from nwk-aaemail-lapp02.apple.com (nwk-aaemail-lapp02.apple.com [17.151.62.67]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id A8FE93A0E9B for ; Mon, 12 Oct 2020 09:31:58 -0700 (PDT) Received: from pps.filterd (nwk-aaemail-lapp02.apple.com [127.0.0.1]) by nwk-aaemail-lapp02.apple.com (8.16.0.43/8.16.0.42) with SMTP id 09CGVAMA052117 for ; Mon, 12 Oct 2020 09:31:58 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=apple.com; h=from : content-type : mime-version : subject : message-id : date : to; s=20180706; bh=Wd72JUyEqYLvpukOQK7txwvCcwu3GVgEZ4NuDNnF0vU=; b=tmDiBdDF1l3hosbfjvcZPbUIahrSSqGNCkhyPiWDTVi3L/oni5JaAIqQFGBjLhq3249D E+U1AzYMwr/kShWVr7tHm7kpE0RmpRGcnyPJJWaRa7eXbi11rKNgfzH5IwlembLKmTTt BIB0autYKbFPoL4hrrnaFsmo4MRl3CEbcAQgAma/+onND9L3wMFVdC1oSP1aUAkxuo77 5SbtMyUqW3qelodfNSjr2F5Gh+PdRo8Hq5JX1n61VOFuF6/A1w2OoRR2x1y6dUXYq5Nq isVU7mgzfOP9I01WUy5wQdufqNBN6l0m/az/WbUIt1mromrJMQhYg8MY5EeJUtMX+LqU fQ== Received: from rn-mailsvcp-mta-lapp01.rno.apple.com (rn-mailsvcp-mta-lapp01.rno.apple.com [10.225.203.149]) by nwk-aaemail-lapp02.apple.com with ESMTP id 344smsh7h0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NO) for ; Mon, 12 Oct 2020 09:31:58 -0700 Received: from rn-mailsvcp-mmp-lapp02.rno.apple.com (rn-mailsvcp-mmp-lapp02.rno.apple.com [17.179.253.15]) by rn-mailsvcp-mta-lapp01.rno.apple.com (Oracle Communications Messaging Server 8.1.0.6.20200729 64bit (built Jul 29 2020)) with ESMTPS id <0QI300NJ8KLA2PJ0@rn-mailsvcp-mta-lapp01.rno.apple.com> for hls-interest@ietf.org; Mon, 12 Oct 2020 09:31:58 -0700 (PDT) Received: from process_milters-daemon.rn-mailsvcp-mmp-lapp02.rno.apple.com by rn-mailsvcp-mmp-lapp02.rno.apple.com (Oracle Communications Messaging Server 8.1.0.6.20200729 64bit (built Jul 29 2020)) id <0QI300200K9UC700@rn-mailsvcp-mmp-lapp02.rno.apple.com> for hls-interest@ietf.org; Mon, 12 Oct 2020 09:31:58 -0700 (PDT) X-Va-A: X-Va-T-CD: 3f93f9dade3eb50a0475b2a56b082445 X-Va-E-CD: 2313994e20aafb6f37e082087d826789 X-Va-R-CD: c9f7056346bce6f6c203c5cd8593b9bf X-Va-CD: 0 X-Va-ID: 5d28058e-8c55-446f-ae44-ca688bc18e3a X-V-A: X-V-T-CD: 3f93f9dade3eb50a0475b2a56b082445 X-V-E-CD: 2313994e20aafb6f37e082087d826789 X-V-R-CD: c9f7056346bce6f6c203c5cd8593b9bf X-V-CD: 0 X-V-ID: abd35d4b-b9c2-455c-92c2-68cc3497ff1e X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235, 18.0.687 definitions=2020-10-12_14:2020-10-12, 2020-10-12 signatures=0 Received: from [17.232.217.169] (unknown [17.232.217.169]) by rn-mailsvcp-mmp-lapp02.rno.apple.com (Oracle Communications Messaging Server 8.1.0.6.20200729 64bit (built Jul 29 2020)) with ESMTPSA id <0QI300SL1KL92200@rn-mailsvcp-mmp-lapp02.rno.apple.com> for hls-interest@ietf.org; Mon, 12 Oct 2020 09:31:58 -0700 (PDT) From: Roger Pantos Content-type: multipart/alternative; boundary="Apple-Mail=_9AD86D07-F6C6-4E7D-B066-954AEEC16CFF" MIME-version: 1.0 (Mac OS X Mail 14.0 \(3654.0.3.2.61\)) Message-id: Date: Mon, 12 Oct 2020 09:31:57 -0700 To: hls-interest@ietf.org X-Mailer: Apple Mail (2.3654.0.3.2.61) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235, 18.0.687 definitions=2020-10-12_14:2020-10-12, 2020-10-12 signatures=0 Archived-At: Subject: [Hls-interest] FYI: new LL-HLS over HTTP/3 prioritization proposal X-BeenThere: hls-interest@ietf.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Discussions about HTTP Live Streaming \(HLS\)." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 12 Oct 2020 16:32:00 -0000 --Apple-Mail=_9AD86D07-F6C6-4E7D-B066-954AEEC16CFF Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 I wanted to give everyone a heads up about a development related to = LL-HLS. As you may (or may not) know, HTTP/3 = https://tools.ietf.org/html/draft-ietf-quic-http = eliminates the = prioritization scheme employed by HTTP/2, replacing it with a new = optional hinting mechanism = https://tools.ietf.org/html/draft-ietf-httpbis-priority = . This means that we need to redo how LL-HLS prioritization works over H3 = connections. Our current proposal for that is = https://github.com/httpwg/http-extensions/issues/1274#issuecomment-7062818= 40 = =E2=80=94 essentially a static prioritization for LL-HLS resources = declared by the origin, plus some level of mandatory support for = Extensible Priorities on the part of CDNs (or whatever the ultimate = delivery server happens to be). Comments welcome. regards, Roger Pantos Apple Inc.= --Apple-Mail=_9AD86D07-F6C6-4E7D-B066-954AEEC16CFF Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8 I = wanted to give everyone a heads up about a development related = to LL-HLS. As you may (or may not) know, HTTP/3 https://tools.ietf.org/html/draft-ietf-quic-http elimi= nates the prioritization scheme employed by HTTP/2, replacing it with a = new optional hinting mechanism https://tools.ietf.org/html/draft-ietf-httpbis-priority.
This means that we need to redo how LL-HLS = prioritization works over H3 connections. Our current proposal for that = is https://github.com/httpwg/http-extensions/issues/1274#issuecomm= ent-706281840 =E2=80=94 essentially a static prioritization for = LL-HLS resources declared by the origin, plus some level of mandatory = support for Extensible Priorities on the part of CDNs (or whatever the = ultimate delivery server happens to be).

Comments welcome.


regards,

Roger = Pantos
Apple Inc.
= --Apple-Mail=_9AD86D07-F6C6-4E7D-B066-954AEEC16CFF-- From nobody Mon Oct 12 12:54:44 2020 Return-Path: X-Original-To: hls-interest@ietfa.amsl.com Delivered-To: hls-interest@ietfa.amsl.com Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id D0E603A08A6 for ; Mon, 12 Oct 2020 12:54:37 -0700 (PDT) X-Virus-Scanned: amavisd-new at amsl.com X-Spam-Flag: NO X-Spam-Score: -1.848 X-Spam-Level: X-Spam-Status: No, score=-1.848 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.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 zL1mZ4SNRZd7 for ; Mon, 12 Oct 2020 12:54:36 -0700 (PDT) Received: from mail-ed1-x52f.google.com (mail-ed1-x52f.google.com [IPv6:2a00:1450:4864:20::52f]) (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 4AD413A08AB for ; Mon, 12 Oct 2020 12:54:36 -0700 (PDT) Received: by mail-ed1-x52f.google.com with SMTP id cq12so18351303edb.2 for ; Mon, 12 Oct 2020 12:54:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=YDsvhzPj+N+njVy9blcqiQ1YMGEGxdyLdljknd76bis=; b=pNfdSQZhp5MCtyTjDGYI7kjJCa3dCal5WacSuWTLQ/zwRWHErdEQFt5ouI2Fy0x/s7 WBG6dtTpUnp+aqDNJX/dGMYGeneKnS/3aOMz7TXtLcxHSeuvXGuH5AExNjOaIJd5anVc rf52iXnh5Aj5ViDfZ3NS+E6yYQRa5liHbqaoGGkxi/rTcHeuVqR0kym6/cEZ33aAAVJB nf9pqCFX2Okud5H9AGYD+wusSTxG1rWeo4T1R4yLB43VgtTLYCZcC1GAVoUsM3n0JrVH EpHgVpUHQ5rhCgjfuzhTbgVlJXV1oLNI/HkOqmz3TieuquVOrxuRrMYVTP4wqhEFs7oA 2DNQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=YDsvhzPj+N+njVy9blcqiQ1YMGEGxdyLdljknd76bis=; b=QovOzd8pZ++9UnmXQ5frLWHdb49qJTtd6UE2SEA2PJmpGg7VWAR404epgfwj9VJzYq 3uiGUjmZ3sod/s9ylCWhnVnFwhBWFacc5jReKoSA9aoqR33Lpoy3iCNpzXwBC0jE1u8q 8Y+ehIMoixi0EVTKf0P/byUdrQi5mzFe9SiycqyxHGNBSdlGn5YTt0VGcezd2F7bKViy Aa5yTdMIpZzZMQXXWRH/x9wpLsrqXl1sUrc9jjmCrZV3wgcbcrbmDmbMeaDaoRyAueGu +emwitB+3p7IbrL5tAyyXkpjUtN2DFLLwl2Pg4q/vXI0FEpj+ipSwwhCx86kr3Wxcl70 3usA== X-Gm-Message-State: AOAM531ukPcDGbpXZrlLozYUWwlof/0d1HeATTgdoJ90Ia9US1ffrzqZ iHHGwp27DRK3bAS0ynxHWtMTFW+723sxs4XAsv/68sJc X-Google-Smtp-Source: ABdhPJzcUkotGYsJ6Tu/23iw7EfXbvYJtxtxRLhntIVdyBARf1cTDnYVMr2fUtCPqzcFYHUbbCjcwBak1Rdx1/v2kdo= X-Received: by 2002:a05:6402:392:: with SMTP id o18mr16372306edv.283.1602532474809; Mon, 12 Oct 2020 12:54:34 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Lucas Pardue Date: Mon, 12 Oct 2020 20:54:20 +0100 Message-ID: To: Roger Pantos Cc: hls-interest@ietf.org Content-Type: multipart/alternative; boundary="000000000000e6f39505b17eaa29" Archived-At: Subject: Re: [Hls-interest] FYI: new LL-HLS over HTTP/3 prioritization proposal X-BeenThere: hls-interest@ietf.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Discussions about HTTP Live Streaming \(HLS\)." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 12 Oct 2020 19:54:38 -0000 --000000000000e6f39505b17eaa29 Content-Type: text/plain; charset="UTF-8" Hi Roger and LL-HLS folks, I'm one of the editors of the Extensible Priorities document. Roger's given a salient and accurate description but I thought I might provide a little bit more color. HTTP/2 provided a very expressive scheme to communicate priorities: dependencies and weights. A server can use this to schedule resources, typically bandwidth allocation of concurrent responses. But they also have to trade off what a client wants against local operator concerns like preventing DoS. Getting prioirites right is hard and some implementations never really got it right with HTTP/2. HTTP/3 made things harder because QUIC provides no ordering across streams; that breaks dependencies in fun ways. This lead the QUIC and HTTP WGs to Extensible priorities, a simplified scheme that can be applied to both HTTP/2 and HTTP/3. Both tree priorities and extensible priorities focus on signalling, and leave a lot of details about scheduling to the server. I think Roger's proposal is equally applicable to either priority scheme. Detailing effective, application-specific ordering and bandwidth allocation recommendations for servers irrespective of client signals. I do encourage comments here or on the issue. Cheers Lucas > > --000000000000e6f39505b17eaa29 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Hi Roger and LL-HLS folks,

I'm one of the editors of the Extensible Priorities docu= ment. Roger's given a salient and accurate description but I thought I = might provide a little bit more color.

HTTP/2 provided a very expressive scheme to communicate prio= rities: dependencies and weights. A server can use this to schedule resourc= es, typically bandwidth allocation of concurrent responses. But they also h= ave to trade off what a client wants against local operator concerns like p= reventing DoS.=C2=A0

Get= ting prioirites right is hard and some implementations never really got it = right with HTTP/2. HTTP/3 made things harder because QUIC provides no order= ing across streams; that breaks dependencies in fun ways.

This lead the QUIC and HTTP WGs to Extens= ible priorities, a simplified scheme that can be applied to both HTTP/2 and= HTTP/3.

Both tree prior= ities and extensible priorities focus on signalling, and leave a lot of det= ails about scheduling to the server. I think Roger's proposal is equall= y applicable to either priority scheme. Detailing effective, application-sp= ecific ordering and bandwidth allocation recommendations for servers irresp= ective of client signals.

I do encourage comments here or on the issue.

=
Cheers
Lucas



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