Packet Reordering Metrics
RFC 4737
Document | Type |
RFC - Proposed Standard
(November 2006; No errata)
Updated by RFC 6248
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Authors | Al Morton , Gomathi Ramachandran , Stanislav Shalunov , Len Ciavattone , Jerry Perser | ||
Last updated | 2015-10-14 | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Reviews | |||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 4737 (Proposed Standard) | |
Action Holders |
(None)
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Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Lars Eggert | ||
IESG note | rfc 4737 | ||
Send notices to | (None) |
Network Working Group A. Morton Request for Comments: 4737 L. Ciavattone Category: Standards Track G. Ramachandran AT&T Labs S. Shalunov Internet2 J. Perser Veriwave November 2006 Packet Reordering Metrics Status of This Memo This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited. Copyright Notice Copyright (C) The IETF Trust (2006). Abstract This memo defines metrics to evaluate whether a network has maintained packet order on a packet-by-packet basis. It provides motivations for the new metrics and discusses the measurement issues, including the context information required for all metrics. The memo first defines a reordered singleton, and then uses it as the basis for sample metrics to quantify the extent of reordering in several useful dimensions for network characterization or receiver design. Additional metrics quantify the frequency of reordering and the distance between separate occurrences. We then define a metric oriented toward assessment of reordering effects on TCP. Several examples of evaluation using the various sample metrics are included. An appendix gives extended definitions for evaluating order with packet fragmentation. Morton, et al. Standards Track [Page 1] RFC 4737 Packet Reordering Metrics November 2006 Table of Contents 1. Introduction ....................................................4 1.1. Motivation .................................................4 1.2. Goals and Objectives .......................................5 1.3. Required Context for All Reordering Metrics ................6 2. Conventions Used in this Document ...............................7 3. A Reordered Packet Singleton Metric .............................7 3.1. Metric Name ................................................8 3.2. Metric Parameters ..........................................8 3.3. Definition .................................................8 3.4. Sequence Discontinuity Definition ..........................9 3.5. Evaluation of Reordering in Dimensions of Time or Bytes ...10 3.6. Discussion ................................................10 4. Sample Metrics .................................................11 4.1. Reordered Packet Ratio ....................................11 4.1.1. Metric Name ........................................11 4.1.2. Metric Parameters ..................................11 4.1.3. Definition .........................................12 4.1.4. Discussion .........................................12 4.2. Reordering Extent .........................................12 4.2.1. Metric Name ........................................12 4.2.2. Notation and Metric Parameters .....................12 4.2.3. Definition .........................................13 4.2.4. Discussion .........................................13 4.3. Reordering Late Time Offset ...............................14 4.3.1. Metric Name ........................................14 4.3.2. Metric Parameters ..................................14 4.3.3. Definition .........................................15 4.3.4. Discussion .........................................15 4.4. Reordering Byte Offset ....................................16 4.4.1. Metric Name ........................................16 4.4.2. Metric Parameters ..................................16 4.4.3. Definition .........................................16 4.4.4. Discussion .........................................17 4.5. Gaps between Multiple Reordering Discontinuities ..........17 4.5.1. Metric Names .......................................17 4.5.2. Parameters .........................................17 4.5.3. Definition of Reordering Discontinuity .............17 4.5.4. Definition of Reordering Gap .......................18 4.5.5. Discussion .........................................18Show full document text