XR Block Working Group V. Singh Internet-Draft Aalto University Intended status: Standards Track R. Huang Expires: August 18, 2014 R. Even Huawei February 14, 2014 Additional RTP Control Protocol (RTCP) Extended Report (XR) Metrics for WebRTC Statistics API draft-singh-xrblock-webrtc-additional-stats-02 Abstract This document describes a list of additional identifiers used in WebRTC's Javascript statistics API. These identifiers are a set of RTCP XR metrics related to the transport of multimedia flows. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. 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 August 18, 2014. Copyright Notice Copyright (c) 2014 IETF Trust and the persons identified as the document authors. All rights reserved. Singh, et al. Expires August 18, 2014 [Page 1] Internet-Draft Additional RTCP XR Metrics for WebRTC February 2014 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. Candidate XR Block Metrics for WebRTC Statistics API . . . 3 2.1. Variables from XR Blocks . . . . . . . . . . . . . . . . 3 2.1.1. Packets and Octets Discarded . . . . . . . . . . . . 3 2.1.2. Cumulative Number of Packets Repaired . . . . . . . . 4 2.1.3. Burst Packet Loss or Discarded . . . . . . . . . . . 4 2.1.4. Frame Impairment Metrics . . . . . . . . . . . . . . 4 3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 4. Security Considerations . . . . . . . . . . . . . . . . . . . 5 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5 6. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 6.1. Normative References . . . . . . . . . . . . . . . . . . 5 6.2. Informative References . . . . . . . . . . . . . . . . . 6 Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 7 A.1. changes in draft-singh-xrblock-webrtc-additional-stats-01 7 A.2. changes in draft-singh-xrblock-webrtc-additional-stats-00 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7 1. Introduction Web-based real-time communication (WebRTC) deployments are emerging and applications need to be able to estimate the service quality. If sufficient information (metrics or statistics) are provided to the applications, it can attempt to improve the media quality. [I-D.ietf-rtcweb-use-cases-and-requirements] specifies a requirement for statistics: F38 The browser must be able to collect statistics, related to the transport of audio and video between peers, needed to estimate quality of experience. The [I-D.alvestrand-rtcweb-stats-registry] describes a registration procedure for metrics reported by the Javascript API. It currently lists basic metrics reported in the RTCP Sender and Receiver Report (SR/RR) to fulfill this requirement. However, the basic metrics from Singh, et al. Expires August 18, 2014 [Page 2] Internet-Draft Additional RTCP XR Metrics for WebRTC February 2014 RTCP SR/RR are not sufficient for precise quality monitoring or troubleshooting. This document proposes to expose the RTCP XR metrics to complement the identifiers already in the statistics registry [I-D.alvestrand-rtcweb-stats-registry]. In depth discussion about the XR metrics candidates is carried out in [I-D.huang-xrblock-rtcweb-rtcp-xr-metrics]. The WebRTC application has two options to extract the statistics: 1) the browser monitors the local (outgoing) and remote (incoming) RTP stream and exposes metrics to the application via the Stats API [W3C.WD-webrtc-20130910], or 2) the browser measures the remote (incoming) RTP stream and exposes the metrics to the other participant by sending the appropriate RTCP XR. At the moment [I-D.ietf-rtcweb-rtp-usage] does not specify the use of any RTCP XRs and since their usage is optional, the exchange of statistics between participants or a monitoring server is outside the scope of this document. 2. Candidate XR Block Metrics for WebRTC Statistics API This document describes a list of additional identifiers to complement the identifiers in Section 4.1 of [I-D.alvestrand-rtcweb-stats-registry] and these group of identifiers are defined on a ReportGroup corresponding to an SSRC. In practice the application MUST be able to query the statistic identifiers on both an incoming (remote) and outgoing (local) media stream. Depending on the support of the corresponding XR report the endpoint MAY be able to query the reception statistics for its outgoing (local) media stream. The following contact information is used for all registrations in this document: Contact: Varun Singh mailto:varun.singh@iki.fi tel:+358-9-470-24785 2.1. Variables from XR Blocks 2.1.1. Packets and Octets Discarded Name: PacketsDiscarded Definition: Cumulative Number of RTP packets discarded due to late or early-arrival, Appendix A (a) of [RFC7002]. Name: OctetsDiscarded Singh, et al. Expires August 18, 2014 [Page 3] Internet-Draft Additional RTCP XR Metrics for WebRTC February 2014 Definition: Cumulative Number of octets discarded due to late or early-arrival, Appendix A of [I-D.ietf-xrblock-rtcp-xr-bytes-discarded-metric] 2.1.2. Cumulative Number of Packets Repaired Name: PacketsRepaired Definition: The cumulative number of lost RTP packets repaired after applying a error-resilience mechanism, Appendix A (b) of [I-D.huang-xrblock-post-repair-loss-count]. To clarify, the value is upper bound to the cumulative number of lost packets. 2.1.3. Burst Packet Loss or Discarded Name: BurstPacketDiscarded Definition: The total number of RTP packets discarded during discard bursts, Appendix A (b) of [RFC7003]. Name: BurstPacketLost Definition: The total number of RTP packets lost during loss bursts, Appendix A (c) of [RFC6958]. Name: BurstCount Definition: The cumulative number of bursts of lost RTP packets, Appendix A (e) of [RFC6958]. [RFC3611] recommends a Gmin value of 16. 2.1.4. Frame Impairment Metrics Name: FullFramesLostCount Definition: Number of full frames lost, Appendix A (i) of [RFC7004] Name: PartialFramesLostCount Definition: Number of frames partially lost, Appendix A (j) of [RFC7004] Name: FramesDiscardedCount Definition: Number of full frames discarded, Appendix A (g) of [RFC7004] Singh, et al. Expires August 18, 2014 [Page 4] Internet-Draft Additional RTCP XR Metrics for WebRTC February 2014 3. IANA Considerations This document requests IANA to update the registry described in [I-D.alvestrand-rtcweb-stats-registry] with the identifiers defined in Section 2. 4. Security Considerations The security considerations of [I-D.alvestrand-rtcweb-stats-registry], apply. 5. Acknowledgements This document is a product of discussion in XRBLOCK WG, initial motivation for this documented is discussed in [I-D.huang-xrblock-rtcweb-rtcp-xr-metrics] The authors would like to thank Al Morton, Colin Perkins, Dan Romascanu, and Shida Schubert, for their valuable comments and suggestions on earlier version of this document. 6. References 6.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [I-D.alvestrand-rtcweb-stats-registry] Alvestrand, H., "A Registry for WebRTC statistics identifiers", draft-alvestrand-rtcweb-stats-registry-00 (work in progress), September 2012. [RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V. Jacobson, "RTP: A Transport Protocol for Real-Time Applications", STD 64, RFC 3550, July 2003. [RFC3611] Friedman, T., Caceres, R., and A. Clark, "RTP Control Protocol Extended Reports (RTCP XR)", RFC 3611, November 2003. [RFC4588] Rey, J., Leon, D., Miyazaki, A., Varsa, V., and R. Hakenberg, "RTP Retransmission Payload Format", RFC 4588, July 2006. [RFC6958] Clark, A., Zhang, S., Zhao, J., and Q. Wu, "RTP Control Protocol (RTCP) Extended Report (XR) Block for Burst/Gap Loss Metric Reporting", RFC 6958, May 2013. Singh, et al. Expires August 18, 2014 [Page 5] Internet-Draft Additional RTCP XR Metrics for WebRTC February 2014 [RFC7002] Clark, A., Zorn, G., and Q. Wu, "RTP Control Protocol (RTCP) Extended Report (XR) Block for Discard Count Metric Reporting", RFC 7002, September 2013. [RFC7003] Clark, A., Huang, R., and Q. Wu, "RTP Control Protocol (RTCP) Extended Report (XR) Block for Burst/Gap Discard Metric Reporting", RFC 7003, September 2013. [I-D.ietf-xrblock-rtcp-xr-bytes-discarded-metric] Singh, V., Ott, J., and I. Curcio, "RTP Control Protocol (RTCP) Extended Report (XR) for Bytes Discarded Metric", draft-ietf-xrblock-rtcp-xr-bytes-discarded-metric-00 (work in progress), October 2013. [I-D.huang-xrblock-post-repair-loss-count] Huang, R. and V. Singh, "RTP Control Protocol (RTCP) Extended Report (XR) for Post-Repair Non-Run Length Encoding (RLE) Loss Count Metrics", draft-huang-xrblock- post-repair-loss-count-00 (work in progress), September 2013. [RFC7004] Zorn, G., Schott, R., Wu, Q., and R. Huang, "RTP Control Protocol (RTCP) Extended Report (XR) Blocks for Summary Statistics Metrics Reporting", RFC 7004, September 2013. 6.2. Informative References [I-D.ietf-rtcweb-use-cases-and-requirements] Holmberg, C., Hakansson, S., and G. Eriksson, "Web Real- Time Communication Use-cases and Requirements", draft- ietf-rtcweb-use-cases-and-requirements-10 (work in progress), December 2012. [I-D.huang-xrblock-rtcweb-rtcp-xr-metrics] Huang, R., Even, R., and V. Singh, "Consideration for Selecting RTCP Extended Report (XR) Metrics for RTCWEB Statistics API", draft-huang-xrblock-rtcweb-rtcp-xr- metrics-01 (work in progress), July 2013. [W3C.WD-webrtc-20130910] Bergkvist, A., Burnett, D., Jennings, C., and A. Narayanan, "WebRTC 1.0: Real-time Communication Between Browsers", World Wide Web Consortium WD WD- webrtc-20130910, September 2013, . [I-D.ietf-rtcweb-rtp-usage] Singh, et al. Expires August 18, 2014 [Page 6] Internet-Draft Additional RTCP XR Metrics for WebRTC February 2014 Perkins, C., Westerlund, M., and J. Ott, "Web Real-Time Communication (WebRTC): Media Transport and Use of RTP", draft-ietf-rtcweb-rtp-usage-11 (work in progress), December 2013. Appendix A. Change Log Note to the RFC-Editor: please remove this section prior to publication as an RFC. A.1. changes in draft-singh-xrblock-webrtc-additional-stats-01 o Addressed comments from the Vancouver IETF meeting. o Added Burst discard/loss metric. o Removed retransmission metric. A.2. changes in draft-singh-xrblock-webrtc-additional-stats-00 o Clarified measurement points for remote (incoming) media stream and local (outgoing) media stream. o Added this section. Authors' Addresses Varun Singh Aalto University School of Electrical Engineering Otakaari 5 A Espoo, FIN 02150 Finland Email: varun@comnet.tkk.fi URI: http://www.netlab.tkk.fi/~varun/ Rachel Huang Huawei 101 Software Avenue, Yuhua District Nanjing, CN 210012 China Email: rachel.huang@huawei.com Singh, et al. Expires August 18, 2014 [Page 7] Internet-Draft Additional RTCP XR Metrics for WebRTC February 2014 Roni Even Huawei 14 David Hamelech Tel Aviv 64953 Israel Email: roni.even@mail01.huawei.com Singh, et al. Expires August 18, 2014 [Page 8]