Network Working Group                                           R. Huang
Internet-Draft                                                     Q. Wu
Intended status: Standards Track                                  Huawei
Expires: April 19, 2011                                 October 16, 2010


  RTCP XR Report Block for TS Decodability Statistics Metric reporting
                draft-huang-avt-rtcp-xr-decodability-00

Abstract

   This document defines an RTCP XR Report Block that allows the
   reporting of Decodability Statistics Metric used for Transport
   Stream.

Status of this Memo

   This Internet-Draft is submitted in full conformance with the
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   This Internet-Draft will expire on April 19, 2011.

Copyright Notice

   Copyright (c) 2010 IETF Trust and the persons identified as the
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   This document is subject to BCP 78 and the IETF Trust's Legal
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   described in the Simplified BSD License.





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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 3
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3
     2.1.  Standards Language  . . . . . . . . . . . . . . . . . . . . 3
     2.2.  Acronyms  . . . . . . . . . . . . . . . . . . . . . . . . . 3
   3.  TR 101 290 Decodability Statistics Metric Report Block  . . . . 3
   4.  SDP Signaling . . . . . . . . . . . . . . . . . . . . . . . . . 6
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7
   6.  Security Considerations . . . . . . . . . . . . . . . . . . . . 8
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . . . 8
     7.1.  Normative References  . . . . . . . . . . . . . . . . . . . 8
     7.2.  Informative References  . . . . . . . . . . . . . . . . . . 8
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . . . 9





































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1.  Introduction

   This draft defines a new block type to augment those defined in
   [RFC3611] for use in Transport Stream.  The new block type supports
   the reporting of consistency of Transport Stream [ETSI].  This new
   block type can be useful for identifying the existence, and
   characterising the severity, of a packet transport problem which may
   affect users' perception of a service delivered over RTP, also useful
   for Verifying the continued correct operation of an existing system
   management and providing accurate measures of Transport Stream
   quality for operators.

   The metric is applicable to any other types of RTP application that
   use TS standard format for transmission and storage of audio, video,
   and data.


2.  Terminology

2.1.  Standards Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

   In addition, the following terms are defined:

2.2.  Acronyms

   SSRC
      Synchronization Source [RFC3550]

   TS
      Transport Stream [ISO-IEC.13818-1.2007]


3.  TR 101 290 Decodability Statistics Metric Report Block

   This block reports decodability statistics metric beyond the
   information carried in the standard RTCP packet format.  Information
   is recorded about the number of Transport Stream Synchronization
   Losses, Sync byte errors, Continuity count errors, Transport errors,
   Program Clock Reference (PCR) errors, PCR repetition errors, PCR
   discontinuity indicator errors, and Presentation Time Stamp (PTS)
   errors [ETSI].  Such information can be useful for network management
   and video quality monitoring.

   Note that this is not only applicable to MPEG-2 RTP streams



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   [RFC2250],but also applicable to any other video codec using
   Transport Stream as input.

   The report block contents are dependent upon a series of flag bits
   carried in the first part of the header.  Not all parameters need to
   be reported in each block.  Flags indicate which are and which are
   not reported.  The fields corresponding to unreported parameters MUST
   be present, but are set to zero.  The receiver MUST ignore any
   Decodability Metrics Block with a non-zero value in any field flagged
   as unreported.

   The Decodability Metrics Block has the following format:

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |     BT=TBD    |L|B|C|T|P|S|rvd|         block length          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        SSRC of source                         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |          begin_seq            |             end_seq           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |       Number of packets       |         Number of TSs         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |             Transport Stream Synchronization Losses           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Sync byte errors                         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Continuity count errors                      |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Transport errors                         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                         PCR errors                            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                   PCR repetition errors                       |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            PCR discontinuity indicator errors                 |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                         PTS errors                            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   block type (BT): 8 bits
      A TR 101 290 decodability metrics report block is identified by
      the constant <TDM>.







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   Transport Stream Synchronization Loss flag (L): 1 bit
      Bit set to 1 if the Transport Stream Synchronization Loss field
      contains a report, 0 otherwise.

   Sync byte error flag (B): 1 bit
      Bit set to 1 if the Sync byte error field contains a report, 0
      otherwise.

   Continuity count error flag (C): 1 bit
      Bit set to 1 if the Continuity count error field contains a
      report, 0 otherwise.

   Transport error flag (T): 1 bit
      Bit set to 1 if the Transport error field contains a report, 0
      otherwise.

   PCR related error flag (P): 1 bit
      Bit set to 1 if the PCR error field, PCR repetition error field
      and PCR discontinuity indicator error fields contain a report, 0
      otherwise.

   PTS error flag (S): 1 bit
      Bit set to 1 if the PTS error field contains a report, 0
      otherwise.

   rvd: 2 bits
      This field is reserved for future definition.  In the absence of
      such a definition, the bits in this field MUST be set to zero and
      MUST be ignored by the receiver.

   block length: 16 bits
      The constant 10, in accordance with the definition of this field
      in Section 3 of RFC 3611 [RFC3611].

   SSRC of source: 32 bits
      As defined in Section 4.1 of [RFC3611].

   begin_seq: 16 bits
      As defined in Section 4.1 of [RFC3611].

   end_seq: 16 bits
      As defined in Section 4.1 of [RFC3611].

   Number of Packets: 16 bits
      Number of RTP packets in the above sequence number interval.






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   Number of TSs: 16 bits
      Number of Transport Streams in the above sequence number interval.

   Transport Stream Synchronization Losses: 32 bits
      Number of Transport Stream Synchronization Losses in the above
      sequence number interval.

   Sync byte errors: 32 bits
      Number of Transport sync byte errors in the above sequence number
      interval.
   Continuity count error: 32 bits
      Number of Transport Continuity count errors in the above sequence
      number interval.

   Transport errors: 32 bits
      Number of Transport errors in the above sequence number interval.

   PCR errors: 32 bits
      Number of PCR errors in the above sequence number interval.

   PCR repetition errors: 32 bits
      Number of Transport PCR repetition errors in the above sequence
      number interval.

   PCR discontinuity indicator errors: 32 bits
      Number of PCR discontinuity indicator errors in the above sequence
      number interval.

   PTS errors: 32 bits
      Number of PTS errors in the above sequence number interval.



4.  SDP Signaling

   One new parameters are defined for the one report blocks defined in
   this document to be used with Session Description Protocol (SDP)
   [RFC4566] using the Augmented Backus-Naur Form (ABNF) [RFC5234].
   They have the following syntax within the "rtcp-xr" attribute
   [RFC3611]:











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   rtcp-xr-attrib =  "a=rtcp-xr:"
                     [xr-format *(SP xr-format)] CRLF

      xr-format = decodability-metrics

         decodability-metrics = "decodability-metrics"
                               ["=" stat-flag *("," stat-flag)]
            stat-flag = "TS Synchronization Loss "
                      / "Sync byte error "
                      / "Continuity count error "
                     / "Transport error"
                     / "PCR related error"
                     / "PTS error"

   Refer to Section 5.1 of RFC 3611 [RFC3611] for a detailed description
   and the full syntax of the "rtcp-xr" attribute.


5.  IANA Considerations

   New report block types for RTCP XR are subject to IANA registration.
   For general guidelines on IANA allocations for RTCP XR, refer to
   Section 6.2 of [RFC3611].

   This document assigns one new block type values in the RTCP XR Block
   Type Registry:

      Name:       TDM
      Long Name:  TR 101 290 Decodability Metrics
      Value       <TDM>
      Reference:  section 3

   This document also registers one SDP [RFC4566] parameters for the
   "rtcp-xr" attribute in the RTCP XR SDP Parameters Registry:

      *  "decodability-metrics"

   The contact information for the registrations is:

                    Rachel Huang
                    Rachel@huawei.com
                    101 Software Avenue, Yuhua District
                    Nanjing, JiangSu 210012 China








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6.  Security Considerations

   TBC


7.  References

7.1.  Normative References

   [ETSI]     ETSI, "Digital Video Broadcasting (DVB); Measurement
              guidelines for DVB systems", Technical Report TR 101 290,
              2001.

   [ISO-IEC.13818-1.2007]
              International Organization for Standardization,
              "Information technology - Generic coding of moving
              pictures and associated audio information: Systems",
              ISO International Standard 13818-1, October 2007.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2250]  Hoffman, D., Fernando, G., Goyal, V., and M. Civanlar,
              "RTP Payload Format for MPEG1/MPEG2 Video", RFC 2250,
              January 1998.

   [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.

   [RFC4566]  Handley, M., Jacobson, V., and C. Perkins, "SDP: Session
              Description Protocol", RFC 4566, July 2006.

   [RFC5234]  Crocker, D. and P. Overell, "Augmented BNF for Syntax
              Specifications: ABNF", STD 68, RFC 5234, January 2008.

7.2.  Informative References

   [DSLF]     Rahrer, T., Ed., Fiandra, Ed., and Wright, Ed., "Triple-
              play Services Quality of Experience (QoE) Requirements",
              DSL Forum Technical Report TR-126, December 2006.

   [G.1082]   ITU-T, "Measurement-based methods for improving the
              robustness of IPTV performance", ITU-T



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              Recommendation G.1082, April 2009.

   [IEEE]     IEEE, "Human Perception of Jitter and Media
              Synchronization", IEEE Journal on Selected Areas in
              Communications Vol. 14, No. 1, January 1996.

   [P.NAMS]   ITU-T, "Non-intrusive parametric model for the Assessment
              of performance of Multimedia Streaming", ITU-T
              Recommendation P.NAMS, November 2009.


Authors' Addresses

   Rachel Huang
   Huawei
   101 Software Avenue, Yuhua District
   Nanjing  210012
   China

   Email: Rachel@huawei.com


   Qin Wu
   Huawei
   101 Software Avenue, Yuhua District
   Nanjing, Jiangsu  210012
   China

   Email: sunseawq@huawei.com






















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