Proportional Integral Controller Enhanced (PIE): A Lightweight Control Scheme to Address the Bufferbloat Problem
RFC 8033
| Document | Type |
RFC - Experimental
(February 2017; Errata)
Was draft-ietf-aqm-pie (aqm WG)
|
|
|---|---|---|---|
| Last updated | 2017-08-24 | ||
| Replaces | draft-pan-aqm-pie | ||
| Stream | IETF | ||
| Formats | plain text pdf html bibtex | ||
| Reviews | |||
| Stream | WG state | Submitted to IESG for Publication (wg milestone: Dec 2015 - Submit first algorit... ) | |
| Document shepherd | Wesley Eddy | ||
| Shepherd write-up | Show (last changed 2016-04-21) | ||
| IESG | IESG state | RFC 8033 (Experimental) | |
| Consensus Boilerplate | Yes | ||
| Telechat date | |||
| Responsible AD | Mirja Kühlewind | ||
| Send notices to | "Wesley Eddy" <wes@mti-systems.com> | ||
| IANA | IANA review state | Version Changed - Review Needed | |
| IANA action state | No IC | ||
Internet Engineering Task Force (IETF) R. Pan
Request for Comments: 8033 P. Natarajan
Category: Experimental Cisco Systems
ISSN: 2070-1721 F. Baker
Unaffiliated
G. White
CableLabs
February 2017
Proportional Integral Controller Enhanced (PIE):
A Lightweight Control Scheme to Address the Bufferbloat Problem
Abstract
Bufferbloat is a phenomenon in which excess buffers in the network
cause high latency and latency variation. 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 latency variation degrade application performance. There
is a pressing need to design intelligent queue management schemes
that can control latency and latency variation, 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 queuing 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.
Pan, et al. Experimental [Page 1]
RFC 8033 PIE February 2017
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for examination, experimental implementation, and
evaluation.
This document defines an Experimental Protocol for the Internet
community. This document is a product of the Internet Engineering
Task Force (IETF). It represents the consensus of the IETF
community. It has received public review and has been approved for
publication by the Internet Engineering Steering Group (IESG). Not
all documents approved by the IESG are a candidate for any level of
Internet Standard; see Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc8033.
Copyright Notice
Copyright (c) 2017 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.
Pan, et al. Experimental [Page 2]
RFC 8033 PIE February 2017
Table of Contents
1. Introduction ....................................................3
2. Terminology .....................................................5
3. Design Goals ....................................................5
4. The Basic PIE Scheme ............................................6
4.1. Random Dropping ............................................7
4.2. Drop Probability Calculation ...............................7
4.3. Latency Calculation ........................................9
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. Derandomization ...........................................14
5.5. Cap Drop Adjustment .......................................15
6. Implementation Cost ............................................15
7. Scope of Experimentation .......................................17
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