Re: [xrblock] Fw: I-D Action: draft-ietf-xrblock-rtcp-xr-discard-05.txt

Qin Wu <bill.wu@huawei.com> Thu, 26 July 2012 10:06 UTC

Return-Path: <bill.wu@huawei.com>
X-Original-To: xrblock@ietfa.amsl.com
Delivered-To: xrblock@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 4E30421F8598 for <xrblock@ietfa.amsl.com>; Thu, 26 Jul 2012 03:06:34 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -5.044
X-Spam-Level:
X-Spam-Status: No, score=-5.044 tagged_above=-999 required=5 tests=[AWL=0.670, BAYES_00=-2.599, HTML_FONT_FACE_BAD=0.884, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_MED=-4]
Received: from mail.ietf.org ([12.22.58.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id dQUkvgiTZCg9 for <xrblock@ietfa.amsl.com>; Thu, 26 Jul 2012 03:06:33 -0700 (PDT)
Received: from dfwrgout.huawei.com (dfwrgout.huawei.com [206.16.17.72]) by ietfa.amsl.com (Postfix) with ESMTP id 8579021F8569 for <xrblock@ietf.org>; Thu, 26 Jul 2012 03:06:33 -0700 (PDT)
Received: from 172.18.9.243 (EHLO dfweml201-edg.china.huawei.com) ([172.18.9.243]) by dfwrg02-dlp.huawei.com (MOS 4.2.3-GA FastPath) with ESMTP id AIC10305; Thu, 26 Jul 2012 06:06:33 -0400 (EDT)
Received: from DFWEML407-HUB.china.huawei.com (10.193.5.132) by dfweml201-edg.china.huawei.com (172.18.9.107) with Microsoft SMTP Server (TLS) id 14.1.323.3; Thu, 26 Jul 2012 03:04:31 -0700
Received: from SZXEML403-HUB.china.huawei.com (10.82.67.35) by dfweml407-hub.china.huawei.com (10.193.5.132) with Microsoft SMTP Server (TLS) id 14.1.323.3; Thu, 26 Jul 2012 03:04:37 -0700
Received: from w53375 (10.138.41.149) by szxeml403-hub.china.huawei.com (10.82.67.35) with Microsoft SMTP Server (TLS) id 14.1.323.3; Thu, 26 Jul 2012 18:04:28 +0800
Message-ID: <67F0978528C54557A1F367272F8EA310@china.huawei.com>
From: Qin Wu <bill.wu@huawei.com>
To: Glen Zorn <glenzorn@gmail.com>, xrblock@ietf.org
References: <D8C720B9E77243D0BE6C58CA45A2A735@china.huawei.com><88D9BF6DCE6840D3B896E0C0445265B9@china.huawei.com> <1343283100.7688.259.camel@gwz-laptop>
Date: Thu, 26 Jul 2012 18:04:27 +0800
MIME-Version: 1.0
Content-Type: multipart/alternative; boundary="----=_NextPart_000_0F43_01CD6B59.1904D1A0"
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook Express 6.00.2900.5931
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6109
X-Originating-IP: [10.138.41.149]
X-CFilter-Loop: Reflected
Subject: Re: [xrblock] Fw: I-D Action: draft-ietf-xrblock-rtcp-xr-discard-05.txt
X-BeenThere: xrblock@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: Metric Blocks for use with RTCP's Extended Report Framework working group discussion list <xrblock.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/xrblock>, <mailto:xrblock-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/xrblock>
List-Post: <mailto:xrblock@ietf.org>
List-Help: <mailto:xrblock-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/xrblock>, <mailto:xrblock-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 26 Jul 2012 10:06:34 -0000

In my understanding, PDV actually means "Jitter". The effects of PDV in RTP stream can be countered by a properly sized play-out buffer at the receiver. If the packet arrives too late or too late, this packet will not be played-out and then regarded as discard. In other words, if PDV or 'network jitter' is not smoothed out, then the effect of PDV can not be coutered by playout buffer. That is why we say Early/late discards are regarded as a symptom of PDV.

Regards!
-Qin

----- Original Message ----- 
  From: Glen Zorn 
  To: xrblock@ietf.org 
  Sent: Thursday, July 26, 2012 2:11 PM
  Subject: Re: [xrblock] Fw: I-D Action: draft-ietf-xrblock-rtcp-xr-discard-05.txt


  On Wed, 2012-07-25 at 14:49 +0800, Qin Wu wrote: 
Based on Alan's proposal to the open issue mentioed below, we like to add one new section after SDP signaling section as follows:
"
6. Consideration for duplicate packets discards

Early/ late discards are usually regarded as a symptom of PDV due to congestion (or route changes) however duplicate packets discards have quite different causes.

Why is PDV mentioned here?  

  ... 


------------------------------------------------------------------------------


  _______________________________________________
  xrblock mailing list
  xrblock@ietf.org
  https://www.ietf.org/mailman/listinfo/xrblock