[aqm] [Errata Verified] RFC8033 (5095)

RFC Errata System <rfc-editor@rfc-editor.org> Wed, 04 March 2020 11:01 UTC

Return-Path: <wwwrun@rfc-editor.org>
X-Original-To: aqm@ietfa.amsl.com
Delivered-To: aqm@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 27B4F3A0C4E; Wed, 4 Mar 2020 03:01:15 -0800 (PST)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -0.901
X-Spam-Level:
X-Spam-Status: No, score=-0.901 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, CTE_8BIT_MISMATCH=0.999, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=no autolearn_force=no
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 5eNq2ZI_Gb8L; Wed, 4 Mar 2020 03:01:14 -0800 (PST)
Received: from rfc-editor.org (rfc-editor.org [4.31.198.49]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 2F04E3A0C4B; Wed, 4 Mar 2020 03:01:14 -0800 (PST)
Received: by rfc-editor.org (Postfix, from userid 30) id 823B7F40721; Wed, 4 Mar 2020 03:00:52 -0800 (PST)
To: liang_tian@affirmednetworks.com, ropan@cisco.com, prenatar@cisco.com, fredbaker.ietf@gmail.com, g.white@cablelabs.com
X-PHP-Originating-Script: 30:errata_mail_lib.php
From: RFC Errata System <rfc-editor@rfc-editor.org>
Cc: ietf@kuehlewind.net, iesg@ietf.org, aqm@ietf.org, rfc-editor@rfc-editor.org
Content-Type: text/plain; charset=UTF-8
Message-Id: <20200304110052.823B7F40721@rfc-editor.org>
Date: Wed, 4 Mar 2020 03:00:52 -0800 (PST)
Archived-At: <https://mailarchive.ietf.org/arch/msg/aqm/7tGTgyh2sESphtJhmMKJ7HzVHXM>
Subject: [aqm] [Errata Verified] RFC8033 (5095)
X-BeenThere: aqm@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: "Discussion list for active queue management and flow isolation." <aqm.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/aqm>, <mailto:aqm-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/aqm/>
List-Post: <mailto:aqm@ietf.org>
List-Help: <mailto:aqm-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/aqm>, <mailto:aqm-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 04 Mar 2020 11:01:15 -0000

The following errata report has been verified for RFC8033,
"Proportional Integral Controller Enhanced (PIE): A Lightweight Control Scheme to Address the Bufferbloat Problem". 

--------------------------------------
You may review the report below and at:
https://www.rfc-editor.org/errata/eid5095

--------------------------------------
Status: Verified
Type: Technical

Reported by: Liang Tian <liang_tian@affirmednetworks.com>
Date Reported: 2017-08-24
Verified by: Mirja K├╝hlewind (IESG)

Section: 5.2

Original Text
-------------
      if PIE->in_measurement_ == TRUE:
         PIE->dq_count_ = PIE->dq_count_ + deque_pkt_size;
         if PIE->dq_count_ >= DQ_THRESHOLD then
            weight = DQ_THRESHOLD/2^16
            PIE->avg_dq_time_ = (now - PIE->measurement_start_) *
                                weight + PIE->avg_dq_time_ *
                                (1 - weight);
            PIE->dq_count_ = 0;
            PIE->measurement_start_ = now
         else
            PIE->in_measurement_ = FALSE;

Corrected Text
--------------
      if PIE->in_measurement_ == TRUE:
         PIE->dq_count_ = PIE->dq_count_ + deque_pkt_size;
         if PIE->dq_count_ >= DQ_THRESHOLD then
            weight = DQ_THRESHOLD/2^16
            PIE->avg_dq_time_ = (now - PIE->measurement_start_) *
                                weight + PIE->avg_dq_time_ *
                                (1 - weight);
            PIE->in_measurement_ = FALSE;

Notes
-----
There should not be an "else" because if PIE->dq_count_ >= DQ_THRESHOLD, this measurement is over: avg_dq_time is calculated and in_measurement is set to FALSE; otherwise dq_count has been increased before this "if" and now we wait for next packet. Resetting dq_count and measurement_start is not necessary because they will be set again when a new measurement begins.

--------------------------------------
RFC8033 (draft-ietf-aqm-pie-10)
--------------------------------------
Title               : Proportional Integral Controller Enhanced (PIE): A Lightweight Control Scheme to Address the Bufferbloat Problem
Publication Date    : February 2017
Author(s)           : R. Pan, P. Natarajan, F. Baker, G. White
Category            : EXPERIMENTAL
Source              : Active Queue Management and Packet Scheduling
Area                : Transport
Stream              : IETF
Verifying Party     : IESG