--- 1/draft-ietf-rmcat-eval-criteria-05.txt 2016-09-22 06:16:04.337448141 -0700 +++ 2/draft-ietf-rmcat-eval-criteria-06.txt 2016-09-22 06:16:04.369448927 -0700 @@ -1,21 +1,21 @@ RMCAT WG V. Singh Internet-Draft callstats.io Intended status: Informational J. Ott -Expires: September 22, 2016 Technical University of Munich +Expires: March 26, 2017 Technical University of Munich S. Holmer Google - March 21, 2016 + September 22, 2016 Evaluating Congestion Control for Interactive Real-time Media - draft-ietf-rmcat-eval-criteria-05 + draft-ietf-rmcat-eval-criteria-06 Abstract The Real-time Transport Protocol (RTP) is used to transmit media in telephony and video conferencing applications. This document describes the guidelines to evaluate new congestion control algorithms for interactive point-to-point real-time media. Status of This Memo @@ -25,21 +25,21 @@ Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. 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." - This Internet-Draft will expire on September 22, 2016. + This Internet-Draft will expire on March 26, 2017. Copyright Notice Copyright (c) 2016 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 @@ -57,46 +57,48 @@ 3.1. RTP Log Format . . . . . . . . . . . . . . . . . . . . . 5 4. List of Network Parameters . . . . . . . . . . . . . . . . . 5 4.1. One-way Propagation Delay . . . . . . . . . . . . . . . . 5 4.2. End-to-end Loss . . . . . . . . . . . . . . . . . . . . . 5 4.3. DropTail Router Queue Length . . . . . . . . . . . . . . 6 4.4. Loss generation model . . . . . . . . . . . . . . . . . . 6 4.5. Jitter models . . . . . . . . . . . . . . . . . . . . . . 6 4.5.1. Random Bounded PDV (RBPDV) . . . . . . . . . . . . . 7 4.5.2. Approximately Random Subject to No-Reordering Bounded PDV (NR-RPVD) . . . . . . . . . . . . . . . . 8 + 4.5.3. Recommended distribution . . . . . . . . . . . . . . 9 5. WiFi or Cellular Links . . . . . . . . . . . . . . . . . . . 9 6. Traffic Models . . . . . . . . . . . . . . . . . . . . . . . 9 6.1. TCP taffic model . . . . . . . . . . . . . . . . . . . . 9 - 6.2. RTP Video model . . . . . . . . . . . . . . . . . . . . . 9 + 6.2. RTP Video model . . . . . . . . . . . . . . . . . . . . . 10 6.3. Background UDP . . . . . . . . . . . . . . . . . . . . . 10 7. Security Considerations . . . . . . . . . . . . . . . . . . . 10 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10 9. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 10 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 10 - 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 10 - 11.1. Normative References . . . . . . . . . . . . . . . . . . 10 - 11.2. Informative References . . . . . . . . . . . . . . . . . 11 - Appendix A. Application Trade-off . . . . . . . . . . . . . . . 12 - A.1. Measuring Quality . . . . . . . . . . . . . . . . . . . . 12 + 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 + 11.1. Normative References . . . . . . . . . . . . . . . . . . 11 + 11.2. Informative References . . . . . . . . . . . . . . . . . 12 + Appendix A. Application Trade-off . . . . . . . . . . . . . . . 13 + A.1. Measuring Quality . . . . . . . . . . . . . . . . . . . . 13 Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 13 - B.1. Changes in draft-ietf-rmcat-eval-criteria-05 . . . . . . 13 - B.2. Changes in draft-ietf-rmcat-eval-criteria-04 . . . . . . 13 - B.3. Changes in draft-ietf-rmcat-eval-criteria-03 . . . . . . 13 - B.4. Changes in draft-ietf-rmcat-eval-criteria-02 . . . . . . 13 - B.5. Changes in draft-ietf-rmcat-eval-criteria-01 . . . . . . 13 - B.6. Changes in draft-ietf-rmcat-eval-criteria-00 . . . . . . 13 - B.7. Changes in draft-singh-rmcat-cc-eval-04 . . . . . . . . . 13 - B.8. Changes in draft-singh-rmcat-cc-eval-03 . . . . . . . . . 14 - B.9. Changes in draft-singh-rmcat-cc-eval-02 . . . . . . . . . 14 - B.10. Changes in draft-singh-rmcat-cc-eval-01 . . . . . . . . . 14 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14 + B.1. Changes in draft-ietf-rmcat-eval-criteria-06 . . . . . . 13 + B.2. Changes in draft-ietf-rmcat-eval-criteria-05 . . . . . . 13 + B.3. Changes in draft-ietf-rmcat-eval-criteria-04 . . . . . . 13 + B.4. Changes in draft-ietf-rmcat-eval-criteria-03 . . . . . . 13 + B.5. Changes in draft-ietf-rmcat-eval-criteria-02 . . . . . . 13 + B.6. Changes in draft-ietf-rmcat-eval-criteria-01 . . . . . . 14 + B.7. Changes in draft-ietf-rmcat-eval-criteria-00 . . . . . . 14 + B.8. Changes in draft-singh-rmcat-cc-eval-04 . . . . . . . . . 14 + B.9. Changes in draft-singh-rmcat-cc-eval-03 . . . . . . . . . 14 + B.10. Changes in draft-singh-rmcat-cc-eval-02 . . . . . . . . . 14 + B.11. Changes in draft-singh-rmcat-cc-eval-01 . . . . . . . . . 15 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15 1. Introduction This memo describes the guidelines to help with evaluating new congestion control algorithms for interactive point-to-point real time media. The requirements for the congestion control algorithm are outlined in [I-D.ietf-rmcat-cc-requirements]). This document builds upon previous work at the IETF: Specifying New Congestion Control Algorithms [RFC5033] and Metrics for the Evaluation of Congestion Control Algorithms [RFC5166]. @@ -160,21 +162,24 @@ 8. Convergence time: The time taken to reach a stable rate at startup, after the available link capacity changes, or when new flows get added to the bottleneck link. 9. Instability or oscillation in the sending rate: The frequency or number of instances when the sending rate oscillates between an high watermark level and a low watermark level, or vice-versa in a defined time window. For example, the watermarks can be set at 4x interval: 500 Kbps, 2 Mbps, and a time window of 500ms. - 10. Bandwidth Utilization, defined as ratio of the instantaneous + 10. [Editor's note: Section 3, in [I-D.ietf-netvc-testing] contains + objective Metrics for evaluating codecs.] + + 11. Bandwidth Utilization, defined as ratio of the instantaneous sending rate to the instantaneous bottleneck capacity. This metric is useful only when an RMCAT flow is by itself or competing with similar cross-traffic. From the logs the statistical measures (min, max, mean, standard deviation and variance) for the whole duration or any specific part of the session can be calculated. Also the metrics (sending rate, receiver rate, goodput, latency) can be visualized in graphs as variation over time, the measurements in the plot are at 1 second intervals. Additionally, from the logs it is possible to plot the @@ -259,21 +264,21 @@ QueueSize (in bytes) = QueueSize (in sec) x Throughput (in bps)/8 4.4. Loss generation model [Open Issue: Describes the model for generating packet losses, for example, losses can be generated using traces, or using the Gilbert- Elliot model, or randomly (uncorrelated loss).] 4.5. Jitter models - This section defines jitter model for the purposes of this document. + This section defines jitter models for the purposes of this document. When jitter is to be applied to both the RMCAT flow and any competing flow (such as a TCP competing flow), the competing flow will use the jitter definition below that does not allow for re-ordering of packets on the competing flow (see NR-RBPDV definition below). Jitter is an overloaded term in communications. Its meaning is typically associated with the variation of a metric (e.g., delay) with respect to some reference metric (e.g., average delay or minimum delay). For example, RFC 3550 jitter is a smoothed estimate of jitter which is particularly meaningful if the underlying packet @@ -285,43 +290,43 @@ PDV in their documents (e.g., RFC 3393) and as the ITU-T SG16 has defined IP Packet Delay Variation (IPDV) in their documents (e.g., Y.1540). Most PDV distributions in packet network systems are one-sided distributions (the measurement of which with a finite number of measurement samples result in one-sided histograms). In the usual packet network transport case there is typically one packet that transited the network with the minimum delay, then a majority of packets also transit the system within some variation from this - minimum delay, and then a minority of the packets transits the - network with delays higher than the median or average transit time - (these are outliers). Although infrequent, outliers can cause - significant deleterious operation in adaptive systems and should be - considered in RMCAT adaptation designs. + minimum delay, and then a minority of the packets transit the network + with delays higher than the median or average transit time (these are + outliers). Although infrequent, outliers can cause significant + deleterious operation in adaptive systems and should be considered in + RMCAT adaptation designs. In this section we define two different bounded PDV characteristics, 1) Random Bounded PDV and 2) Approximately Random Subject to No- Reordering Bounded PDV. [Open issue: which one is used in evaluations? Are both used?] 4.5.1. Random Bounded PDV (RBPDV) The RBPDV probability distribution function (pdf) is specified to be of some mathematically describable function which includes some practical minimum and maximum discrete values suitable for testing. For example, the minimum value, x_min, might be specified as the minimum transit time packet and the maximum value, x_max, might be idefined to be two standard deviations higher than the mean. Since we are typically interested in the distribution relative to the - mean delay packet, we define the zero mean PVD sample, z(n), to be + mean delay packet, we define the zero mean PDV sample, z(n), to be z(n) = x(n) - x_mean, where x(n) is a sample of the RBPDV random variable x and x_mean is the mean of x. We assume here that s(n) is the original source time of packet n and the post-jitter induced emmission time, j(n), for packet n is j(n) = {[z(n) + x_mean] + s(n)}. It follows that the separation in the post- jitter time of packets n and n+1 is {[s(n+1)-s(n)] - [z(n)-z(n+1)]}. Since the first term is always a positive quantity, we note that packet reordering at the receiver is possible whenever the second term is greater than the first. Said another way, whenever the @@ -364,32 +369,33 @@ multitude of software controlled elements common on end-to-end Internet paths (such as firewalls, ALGs and other middleboxes) which stop processing packets while servicing other functions (e.g., garbage collection). Often these devices do not drop packets, but rather queue them for later processing and cause many of the outliers. Thus NR-RPVD models this particular use case (assuming serial(n+1) is defined appropriately for the device causing the outlier) and thus is believed to be important for adaptation development for RMCAT. - [Editor's Note: It may require to define test distributions as well. - Example test distribution may include- +4.5.3. Recommended distribution - 1 - Two-sided: Uniform PDV Distribution. Two quantities to define: - x_min and x_max. + It is recommended that z(n) is distributed according to a truncated + Gaussian: - 2 - Two-sided: Truncated Gaussian PDV Distribution. Four quantities - to define: the appropriate x_min and x_max for test (e.g., +/- two - sigma values), the standard deviation, and the mean. + z(n) ~ |max(min(N(0, std^2), N_STD * std), -N_STD * std)| - 3 - One Sided: Truncated Gaussian PDV Distribution. Quantities to - define: three sigma value, the standard deviation, and the mean] + where N(0, std^2) is the Gaussian distribution with zero mean and + standard deviation std. Recommended values: + + o std = 5 ms + + o N_STD = 3 5. WiFi or Cellular Links [I-D.ietf-rmcat-wireless-tests] describes the test cases to simulate networks with wireless links. The document describes mechanism to simulate both cellular and WiFi networks. 6. Traffic Models 6.1. TCP taffic model @@ -416,31 +422,31 @@ http://httparchive.org/interesting.php as of October 2015]. 6.2. RTP Video model [I-D.ietf-rmcat-video-traffic-model] describes two types of video traffic models for evaluating RMCAT candidate algorithms. The first model statistically characterizes the behavior of a video encoder. Whereas the second model uses video traces. For example, test sequences are available at: [xiph-seq] and - [HEVC-seq]. - - [Open issue: Which sequences are used? All? Some subset?] + [HEVC-seq]. The currently chosen video streams are: Foreman and + FourPeople. 6.3. Background UDP - [Open issue: Background UDP flow is modeled as a constant bit rate - (CBR) flow. It will download data at a particular CBR rate for the - complete session, or will change to particular CBR rate at predefined - intervals. They parameters are still TBD. e.g., packet size, packet - spacing interval, etc.] + Background UDP flow is modeled as a constant bit rate (CBR) flow. It + will download data at a particular CBR rate for the complete session, + or will change to particular CBR rate at predefined intervals. The + inter packet interval is calculated based on the CBR and the packet + size (is typically set to the path MTU size, the default value can be + 1500 bytes). 7. Security Considerations Security issues have not been discussed in this memo. 8. IANA Considerations There are no IANA impacts in this memo. 9. Contributors @@ -529,36 +535,37 @@ [I-D.ietf-rmcat-eval-test] Sarker, Z., Varun, V., Zhu, X., and M. Ramalho, "Test Cases for Evaluating RMCAT Proposals", draft-ietf-rmcat- eval-test-03 (work in progress), March 2016. [I-D.ietf-rmcat-video-traffic-model] Zhu, X., Cruz, S., and Z. Sarker, "Modeling Video Traffic Sources for RMCAT Evaluations", draft-ietf-rmcat-video- traffic-model-00 (work in progress), January 2016. - [SA4-EVAL] - R1-081955, 3GPP., "LTE Link Level Throughput Data for SA4 - Evaluation Framework", 3GPP R1-081955, 5 2008. + [I-D.ietf-netvc-testing] + Daede, T., Norkin, A., and I. Brailovskiy, "Video Codec + Testing and Quality Measurement", draft-ietf-netvc- + testing-03 (work in progress), July 2016. [SA4-LR] S4-050560, 3GPP., "Error Patterns for MBMS Streaming over UTRAN and GERAN", 3GPP S4-050560, 5 2008. [TCP-eval-suite] Lachlan, A., Marcondes, C., Floyd, S., Dunn, L., Guillier, R., Gang, W., Eggert, L., Ha, S., and I. Rhee, "Towards a Common TCP Evaluation Suite", Proc. PFLDnet. 2008, August 2008. [xiph-seq] - Xiph.org, , "Video Test Media", - http://media.xiph.org/video/derf/ , . + Daede, T., "Video Test Media Set", + https://people.xiph.org/~tdaede/sets/ , . [HEVC-seq] HEVC, , "Test Sequences", http://www.netlab.tkk.fi/~varun/test_sequences/ , . Appendix A. Application Trade-off Application trade-off is yet to be defined. see RMCAT requirements [I-D.ietf-rmcat-cc-requirements] document. Perhaps each experiment should define the application's expectation or trade-off. @@ -569,91 +576,95 @@ currently an open issue. However, there is consensus that congestion control algorithm should be able to show that it is useful for interactive video by performing analysis using a real codec and video sequences. Appendix B. Change Log Note to the RFC-Editor: please remove this section prior to publication as an RFC. -B.1. Changes in draft-ietf-rmcat-eval-criteria-05 +B.1. Changes in draft-ietf-rmcat-eval-criteria-06 + + o Updated Jitter. + +B.2. Changes in draft-ietf-rmcat-eval-criteria-05 o Improved text surrounding wireless tests, video sequences, and short-TCP model. -B.2. Changes in draft-ietf-rmcat-eval-criteria-04 +B.3. Changes in draft-ietf-rmcat-eval-criteria-04 o Removed the guidelines section, as most of the sections are now covered: wireless tests, video model, etc. o Improved Short TCP model based on the suggestion to use httparchive.org. -B.3. Changes in draft-ietf-rmcat-eval-criteria-03 +B.4. Changes in draft-ietf-rmcat-eval-criteria-03 o Keep-alive version. o Moved link parameters and traffic models from eval-test -B.4. Changes in draft-ietf-rmcat-eval-criteria-02 +B.5. Changes in draft-ietf-rmcat-eval-criteria-02 o Incorporated fairness test as a working test. o Updated text on mimimum evaluation requirements. -B.5. Changes in draft-ietf-rmcat-eval-criteria-01 +B.6. Changes in draft-ietf-rmcat-eval-criteria-01 o Removed Appendix B. o Removed Section on Evaluation Parameters. -B.6. Changes in draft-ietf-rmcat-eval-criteria-00 +B.7. Changes in draft-ietf-rmcat-eval-criteria-00 o Updated references. o Resubmitted as WG draft. -B.7. Changes in draft-singh-rmcat-cc-eval-04 +B.8. Changes in draft-singh-rmcat-cc-eval-04 o Incorporate feedback from IETF 87, Berlin. o Clarified metrics: convergence time, bandwidth utilization. o Changed fairness criteria to fairness test. o Added measuring pre- and post-repair loss. o Added open issue of measuring video quality to appendix. o clarified use of DropTail and AQM. o Updated text in "Minimum Requirements for Evaluation" -B.8. Changes in draft-singh-rmcat-cc-eval-03 +B.9. Changes in draft-singh-rmcat-cc-eval-03 o Incorporate the discussion within the design team. o Added a section on evaluation parameters, it describes the flow and network characteristics. o Added Appendix with self-fairness experiment. o Changed bottleneck parameters from a proposal to an example set. o -B.9. Changes in draft-singh-rmcat-cc-eval-02 +B.10. Changes in draft-singh-rmcat-cc-eval-02 o Added scenario descriptions. -B.10. Changes in draft-singh-rmcat-cc-eval-01 +B.11. Changes in draft-singh-rmcat-cc-eval-01 o Removed QoE metrics. o Changed stability to steady-state. o Added measuring impact against few and many flows. o Added guideline for idle and data-limited periods. o Added reference to TCP evaluation suite in example evaluation @@ -653,28 +664,29 @@ o Changed stability to steady-state. o Added measuring impact against few and many flows. o Added guideline for idle and data-limited periods. o Added reference to TCP evaluation suite in example evaluation scenarios. Authors' Addresses + Varun Singh - Nemu Dialogue Systems Oy + CALLSTATS I/O Oy Runeberginkatu 4c A 4 Helsinki 00100 Finland - Email: varun.singh@iki.fi - URI: http://www.callstats.io/ + Email: varun@callstats.io + URI: https://www.callstats.io/about Joerg Ott Technical University of Munich Faculty of Informatics Boltzmannstrasse 3 Garching bei Muenchen, DE 85748 Germany Email: ott@in.tum.de