PIE: A Lightweight Control Scheme To Address the Bufferbloat Problem
draft-ietf-aqm-pie-08

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Internet Draft                                     R. Pan, Cisco Systems
Active Queue Management                      P. Natarajan, Cisco Systems
Working Group                                    F. Baker, Cisco Systems
Intended Status: Experimental Track                  G. White, CableLabs

Expires: December 2, 2016                                   May 31, 2016

           PIE: A Lightweight Control Scheme To Address the 
                          Bufferbloat Problem 

                      draft-ietf-aqm-pie-08

Abstract

   Bufferbloat is a phenomenon in which excess buffers in the network
   cause high latency and jitter. As more and more interactive
   applications (e.g. voice over IP, real time video streaming and
   financial transactions) run in the Internet, high latency and jitter
   degrade application performance. There is a pressing need to design
   intelligent queue management schemes that can control latency and
   jitter, and hence provide desirable quality of service to users.

   This document presents a lightweight active queue management design,
   called PIE (Proportional Integral controller Enhanced), that can
   effectively control the average queueing latency to a target value.
   Simulation results, theoretical analysis and Linux testbed results
   have shown that PIE can ensure low latency and achieve high link
   utilization under various congestion situations. The design does not
   require per-packet timestamps, so it incurs very little overhead and
   is simple enough to implement in both hardware and software. 

Status of this Memo

   This Internet-Draft is submitted to IETF in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF), its areas, and its working groups.  Note that
   other groups may also distribute working documents as
   Internet-Drafts.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."
 

Pan et al.              Expires December 2, 2016                [Page 1]

INTERNET DRAFT                    PIE                       May 31, 2016

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Copyright and License Notice

   Copyright (c) 2012 IETF Trust and the persons identified as the
   document authors. All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document. Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document. Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1. Introduction  . . . . . . . . . . . . . . . . . . . . . . . . .  4
   2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . .  5
   3. Design Goals  . . . . . . . . . . . . . . . . . . . . . . . . .  5
   4. The Basic PIE Scheme  . . . . . . . . . . . . . . . . . . . . .  6
     4.1 Random Dropping(ECN Support is described later in this
         document)  . . . . . . . . . . . . . . . . . . . . . . . . .  7
     4.2 Drop Probability Calculation . . . . . . . . . . . . . . . .  8
     4.3 Latency Calculation  . . . . . . . . . . . . . . . . . . . . 10
     4.4 Burst Tolerance  . . . . . . . . . . . . . . . . . . . . . . 10
   5. Optional Design Elements of PIE . . . . . . . . . . . . . . . . 11
     5.1 ECN Support  . . . . . . . . . . . . . . . . . . . . . . . . 11
     5.2 Dequeue Rate Estimation  . . . . . . . . . . . . . . . . . . 11
     5.3 Setting PIE active and inactive  . . . . . . . . . . . . . . 13
     5.4 De-randomization . . . . . . . . . . . . . . . . . . . . . . 14
     5.5 Cap Drop Adjustment  . . . . . . . . . . . . . . . . . . . . 15
   6. Implementation Cost . . . . . . . . . . . . . . . . . . . . . . 15
   7. Future Research . . . . . . . . . . . . . . . . . . . . . . . . 16
   8. Incremental Deployment  . . . . . . . . . . . . . . . . . . . . 17
   9. Security Considerations . . . . . . . . . . . . . . . . . . . . 17
   10. IANA Considerations  . . . . . . . . . . . . . . . . . . . . . 17
   11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 18
     11.1  Normative References . . . . . . . . . . . . . . . . . . . 18
 

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