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Versions: 00 01 02

XR Block Working Group                                          V. Singh
Internet-Draft                                          Aalto University
Intended status: Standards Track                                R. Huang
Expires: April 20, 2014                                          R. Even
                                                                  Huawei
                                                        October 17, 2013


Additional RTP Control Protocol (RTCP) Extended Report (XR) Metrics for
                         WebRTC Statistics API
             draft-singh-xrblock-webrtc-additional-stats-01

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
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   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 April 20, 2014.

Copyright Notice

   Copyright (c) 2013 IETF Trust and the persons identified as the
   document authors.  All rights reserved.












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   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
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   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 Retransmitted Packets Received .   4
       2.1.3.  Cumulative Number of Packets Repaired . . . . . . . .   4
       2.1.4.  Frame Impairment Metrics  . . . . . . . . . . . . . .   4
   3.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   5.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   4
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   5
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .   5
     6.2.  Informative References  . . . . . . . . . . . . . . . . .   6
   Appendix A.  Metrics represented using RFC6390 Template . . . . .   6
   Appendix B.  Change Log . . . . . . . . . . . . . . . . . . . . .   7
     B.1.  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.


   RTCWEB-STATS [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



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   basic metrics from RTCP SR/RR are not sufficient for precise quality
   monitoring or troubleshooting.  This document proposes to expose the
   RTCP XR metrics to better complement the identifiers already in the
   statistics registry.  In depth discussion about the XR metrics
   candidates is carried out in
   [I-D.huang-xrblock-rtcweb-rtcp-xr-metrics].

   The Javascript application on the receiving endpoint extracts the
   statistics for the remote (incoming) media stream from the browser's
   RTP using the Stats API [W3C.WD-webrtc-20130910].  There are multiple
   ways to exchange these observed identifiers with the remote party,
   one of which is to use corresponding RTCP Extension Reports (XRs)
   [RFC3611] and query the statistic identifiers for the local
   (outgoing) media stream.  However, the exchange of statistics of the
   local stream are currently outside the scope of WebRTC.

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 the group of identifiers
   are well defined on a ReportGroup corresponding to an SSRC.  In
   practice the application MUST be able to query the statistic
   identifiers on an incoming media stream (remote stream).  Depending
   on the support of the corresponding XR report the endpoint MAY be
   able to query the statistic identifier for the outgoing media stream
   (local 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, Appendix A of
   [RFC7002]

   Name: OctetsDiscarded





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   Definition: Cumulative Number of octets discarded, Appendix A of
   [I-D.ietf-xrblock-rtcp-xr-bytes-discarded-metric]

2.1.2.  Cumulative Number of Retransmitted Packets Received

   Name: PacketsRetx

   Definition: See Appendix A of this document, [RFCXXXX].

   RFC EDITOR NOTE: please change XXXX in [RFCXXXX] by the new RFC
   number, when assigned and remove this note.

2.1.3.  Cumulative Number of Packets Repaired

   Name: PacketsRepaired

   Definition: Appendix A (b) of
   [I-D.huang-xrblock-post-repair-loss-count]

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]

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




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   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.

   [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.

   [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.



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   [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,
              <http://www.w3.org/TR/2013/WD-webrtc-20130910>.

Appendix A.  Metrics represented using RFC6390 Template

   RFC EDITOR NOTE: please change XXXX in [RFCXXXX] by the new RFC
   number, when assigned and remove this note.

   a.  Number of Packets Retransmitted Metric

       *  Metric Name: Cumulative number of RTP Packets retransmitted

       *  Metric Description: Total number of packets retransmitted from
          the beginning of the session.

       *  Method of Measurement or Calculation: Cumulative number of
          retransmitted packets received from the beginning of the
          session.  The measured value is an unsigned value.  If the
          measured value exceeds 0xFFFFFFFD, the value 0xFFFFFFFE MUST
          be reported to indicate an over-range measurement.  If the
          measurement is unavailable, the value 0xFFFFFFFF MUST be
          reported.

       *  Units of Measurement: The counter is increased by one for
          every retransmitted RTP packet that is received.




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       *  Measurement Point(s) with Potential Measurement Domain: This
          metric reports the number of retransmitted RTP packets
          received by the receiver.  The measurement of these metrics
          are made at the receiving end of the retransmission stream and
          the association of the retransmission and original streams
          should refer to section 5.3 of [RFC4588].

       *  Measurement Timing: This metric is applicable to cumulative
          measurements, which may be the duration of the ongoing RTP
          session.

       *  Use and applications: See section 1 of [RFCXXXX].

       *  Reporting model: Queried periodically by the WebRTC Statistics
          API.

Appendix B.  Change Log

   Note to the RFC-Editor: please remove this section prior to
   publication as an RFC.

B.1.  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



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   Roni Even
   Huawei
   14 David Hamelech
   Tel Aviv  64953
   Israel

   Email: roni.even@mail01.huawei.com











































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