Congestion Exposure (ConEx) Concepts and Use Cases
RFC 6789
Document | Type | RFC - Informational (December 2012; No errata) | |
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Authors | Bob Briscoe , Richard Woundy , Alissa Cooper | ||
Last updated | 2015-10-14 | ||
Stream | Internet Engineering Task Force (IETF) | ||
Formats | plain text html pdf htmlized (tools) htmlized bibtex | ||
Reviews | |||
Stream | WG state | WG Document | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 6789 (Informational) | |
Action Holders |
(None)
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||
Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Wesley Eddy | ||
IESG note | Nandita Dukkipati (nanditad@google.com) is the document shepherd. | ||
Send notices to | (None) |
Internet Engineering Task Force (IETF) B. Briscoe, Ed. Request for Comments: 6789 BT Category: Informational R. Woundy, Ed. ISSN: 2070-1721 Comcast A. Cooper, Ed. CDT December 2012 Congestion Exposure (ConEx) Concepts and Use Cases Abstract This document provides the entry point to the set of documentation about the Congestion Exposure (ConEx) protocol. It explains the motivation for including a ConEx marking at the IP layer: to expose information about congestion to network nodes. Although such information may have a number of uses, this document focuses on how the information communicated by the ConEx marking can serve as the basis for significantly more efficient and effective traffic management than what exists on the Internet today. Status of This Memo This document is not an Internet Standards Track specification; it is published for informational purposes. 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 5741. 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/rfc6789. Briscoe, et al. Informational [Page 1] RFC 6789 ConEx Concepts and Use Cases December 2012 Copyright 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 . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.1. Congestion . . . . . . . . . . . . . . . . . . . . . . . . 5 2.2. Congestion-Volume . . . . . . . . . . . . . . . . . . . . 5 2.3. Rest-of-Path Congestion . . . . . . . . . . . . . . . . . 6 2.4. Definitions . . . . . . . . . . . . . . . . . . . . . . . 6 3. Core Use Case: Informing Traffic Management . . . . . . . . . 7 3.1. Use Case Description . . . . . . . . . . . . . . . . . . . 7 3.2. Additional Benefits . . . . . . . . . . . . . . . . . . . 9 3.3. Comparison with Existing Approaches . . . . . . . . . . . 9 4. Other Use Cases . . . . . . . . . . . . . . . . . . . . . . . 11 5. Deployment Arrangements . . . . . . . . . . . . . . . . . . . 12 6. Experimental Considerations . . . . . . . . . . . . . . . . . 13 7. Security Considerations . . . . . . . . . . . . . . . . . . . 14 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 14 9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 15 10. Informative References . . . . . . . . . . . . . . . . . . . . 15 1. Introduction The power of Internet technology comes from multiplexing shared capacity with packets rather than circuits. Network operators aim to provide sufficient shared capacity, but when too much packet load meets too little shared capacity, congestion results. Congestion appears as either increased delay, dropped packets, or packets explicitly marked with Explicit Congestion Notification (ECN) markings [RFC3168]. As described in Figure 1, congestion control currently relies on the transport receiver detecting these 'Congestion Signals' and informing the transport sender in 'Congestion Feedback Signals'. The sender is then expected to reduce its rate in response. Briscoe, et al. Informational [Page 2] RFC 6789 ConEx Concepts and Use Cases December 2012 This document provides the entry point to the set of documentation about the Congestion Exposure (ConEx) protocol. It focuses on the motivation for including a ConEx marking at the IP layer. (AShow full document text