Network Working Group
Internet Engineering Task Force (IETF)                          R. Huang
Internet-Draft
Request for Comments: 6990                                         Q. Wu
Intended status:
Category: Standards Track                                         Huawei
Expires: December 2, 2013
ISSN: 2070-1721                                                H. Asaeda
                                                                    NICT
                                                                 G. Zorn
                                                             Network Zen
                                                            May 31,
                                                             August 2013

   RTP Control Protocol (RTCP) Extended Report (XR) Block for MPEG2 MPEG-2
  Transport Stream (TS) Program Specific Information (PSI) Independent
               Decodability Statistics Metrics reporting
               draft-ietf-xrblock-rtcp-xr-decodability-12 Reporting

Abstract

   An MPEG2 MPEG-2 Transport Stream (TS) is a standard container format used
   in the transmission and storage of multimedia data.  Unicast/Multicast
   MPEG2  Unicast/
   multicast MPEG-2 TS over RTP is widely deployed in IPTV systems.
   This document defines an RTP Control Protocol (RTCP) Extended Report
   (XR) Block block that allows the reporting of MPEG2 MPEG-2 TS decodability
   statistics metrics related to transmissions of MPEG2 MPEG-2 TS over RTP.
   The metrics specified in the RTCP XR Block block are not dependent on
   Program specific
   information Specific Information (PSI) carried in MPEG MPEG-2 TS.

Status of this This Memo

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   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents an Internet Standards Track document.

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   Internet-Drafts are draft documents valid the IETF community.  It has
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   This Internet-Draft will expire on December 2, 2013.
   http://www.rfc-editor.org/info/rfc6990.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  MPEG2  MPEG-2 Transport Stream Decodability Metrics  . . . . . . .   3
     1.2.  RTCP and RTCP XR Extended Reports  . . . . . . . . . . . . . . . . .   3
     1.3.  Performance Metrics Framework . . . . . . . . . . . . . .   3
     1.4.  Applicability . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .   4
     2.1.
   2.  Standards Language  . . . . . . . . . . . . . . . . . . . . .   4
   3.  MPEG2  MPEG-2 TS PSI Independent PSI-Independent Decodability Statistics Metrics
       Block . . . . . . . . . . . . . . . . . . . . . . . . . . . .   4
   4.  SDP Signaling . . . . . . . . . . . . . . . . . . . . . . . .  7   8
     4.1.  SDP rtcp-xr-attrib rtcp-xr Attribute Extension . . . . . . . . . . . . .   8
     4.2.  Offer/Answer Usage  . . . . . . . . . . . . . . . . . . . .   8
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   8
     5.1.  New RTCP XR Block Type value . Value  . . . . . . . . . . . . . .   8
     5.2.  New RTCP XR SDP Parameter . . . . . . . . . . . . . . . .  8   9
     5.3.  Contact information Information for registrations Registrations . . . . . . . . . .  8   9
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   9
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . .   9
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . . .   9
     8.1.  Normative References  . . . . . . . . . . . . . . . . . . .   9
     8.2.  Informative References  . . . . . . . . . . . . . . . . . . 10
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . .  10

1.  Introduction

1.1.  MPEG2  MPEG-2 Transport Stream Decodability Metrics

   The European Telecommunications Standards Institute (ETSI) has
   defined a set of syntax and information consistency tests and
   corresponding indicators [ETSI] that are recommended for the
   monitoring of MPEG2 MPEG-2 Transport Streams [ISO-IEC.13818-1.2007]. [ISO-IEC.13818-1.2013].  The
   tests and corresponding indicators are grouped according to priority:

   o  First priority - Necessary for decodability (basic monitoring)

   o  Second priority - Recommended for continuous or periodic
      monitoring

   o  Third priority - Recommended for application-dependent monitoring

   This memo is based on information consistency tests and resulting
   indicators defined by ETSI [ETSI] and defines a new block type to
   augment those defined in [RFC3611] for use with MPEG2 MPEG-2 Transport
   Stream (TS) [ISO-IEC.13818-1.2007]. [ISO-IEC.13818-1.2013].  The new block type supports
   reporting of the number of occurrences of each Program Specific
   Information (PSI) Independent PSI-independent
   indicator in the first and second priorities; third priority
   indicators are not supported.

1.2.  RTCP and RTCP XR Extended Reports

   The use of RTCP for reporting is defined in [RFC3550].  [RFC3611]
   defined an extensible structure for reporting using an RTCP Extended
   Report (XR).  This document defines a new Extended Report block for
   use with [RFC3550] and [RFC3611].

1.3.  Performance Metrics Framework

   The

   "Guidelines for Considering New Performance Metrics Framework Metric Development"
   [RFC6390] provides guidance on the definition and specification of
   performance metrics.  The  "Guidelines for Use of the RTP Monitoring Architectures
   Framework" [RFC6792] provides guideline for guidance on the reporting block format
   using RTCP XR.  The new report block described in this memo is in
   compliance with the monitoring architecture specified in [RFC6792]
   and the Performance Metrics Framework performance metrics framework [RFC6390].

1.4.  Applicability

   This block type allows a counts count of MPEG MPEG-2 Transport Stream quality
   metrics that are measured in accordance with ETSI TR 101290 [ETSI] to
   be reported by an endpoint.  These metrics are useful for identifying
   bitstream packetization and transport stream encoding problems that
   may affect the user's perception of a video service delivered over
   RTP.

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].

3.  MPEG2  MPEG-2 TS PSI Independent PSI-Independent Decodability Statistics Metrics Block

   ETSI TR 101290 [ETSI] generally defines metrics related to error
   events while this document contains counts of those metrics defined
   in [ETSI].  The block defined in this document reports MPEG2 MPEG-2 TS PSI
   Independent PSI-
   independent decodability statistics metrics beyond the information
   carried in the standard RTCP packet format, which are measured at the
   receiving end of the RTP stream.  It contains counts of eight metrics
   defined in ETSI TR 101290 [ETSI].  Information is reported about
   basic monitoring parameters necessary to ensure that the TS can be
   decoded
   decoded, including:

   o  Transport Stream Synchronization Losses

   o  Sync byte errors

   o  Continuity count errors

   and continuous monitoring parameters necessary to ensure the
   continuous decoding decoding, including:

   o  Transport errors

   o  Program Clock Reference (PCR) errors

   o  PCR repetition errors

   o  PCR discontinuity indicator errors

   o  PCR accuracy errors

   o  Presentation Time Stamp (PTS) errors
   The other parameters are ignored since they do not apply to all MPEG2
   MPEG-2 implementations.  For further information on these parameters,
   see [ETSI].  Note that when the report of this block spans across
   more than one measurement intervals interval [RFC6776], the count of the
   metrics (e.g., Sync byte errors, PCR errors )defined and PCR errors) defined in [ETSI] may
   reflect a problem in the current or previous measurement interval.

   The MPEG2 MPEG-2 TS PSI Independent PSI-Independent Decodability Statistics 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=MTPID     BT=22     |    Reserved   |         block length         Block Length          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                     SSRC of source Source                            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |          begin_seq            |             end_seq           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      TS_sync_loss_count                       |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Sync_byte_error_count                    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                  Continuity_count_error_count                 |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      Transport_error_count                    |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                        PCR_error_count                        |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                   PCR_repetition_error_count                  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |            PCR_discontinuity_indicator_error_count            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                     PCR_accuracy_error_count                  |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       PTS_error_count                         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   block type

   Block Type (BT): 8 bits

      The MPEG2 MPEG-2 TS PSI Independent PSI-Independent Decodability Statistics Metrics
      Block is identified by the constant <MTPID>. 22.

   Reserved: 8 bits

      These bits are reserved.  They MUST be set to zero by senders and
      ignored by receivers (See (see [RFC6709] section Section 4.2).

   block length:

   Block Length: 16 bits

      The constant 11, in accordance with the definition of this field
      in Section 3 of RFC 3611.  The block MUST be discarded if the
      block length is set to a different value.

   SSRC

   Synchronization source (SSRC) of source: Source: 32 bits

      As defined in Section 4.1 of RFC 3611.

   begin_seq: 16 bits

      The RTP sequence number corresponding to the start of the
      measurement period, as defined in Section 4.1 of RFC 3611.

   end_seq: 16 bits

      The RTP sequence number corresponding to the end of the
      measurement period, as defined in Section 4.1 of RFC 3611.

   TS_sync_loss_count: 32 bits

      A count of the number of TS_sync_loss errors that occurred in the
      above sequence number interval.  A TS_sync_loss error occurs when
      there are two or more consecutive incorrect sync bytes within the
      MPEG TS stream,
      MPEG-2 TS, as defined in section Section 5.2.1 of [ETSI].

   Sync_byte_error_count: 32 bits

      A count of the number of Sync_byte_errors that occurred in the
      above sequence number interval.  A sync byte error occurs when the
      sync byte is not equal to 0x47 in any TS packet contained in the
      MPEG TS stream,
      MPEG-2 TS, as defined in section Section 5.2.1 of [ETSI].

   Continuity_count_error_count: 32 bits

      A count of the number of Continuity_count_errors that occurred in
      the above sequence number interval.  A Continuity_count_error
      occurs when any of the following faults happen within the MPEG MPEG-2
      TS
      stream - -- incorrect packet order, a packet occurs more than twice twice, or
      a packet is lost,as lost, as defined in the section Section 5.2.1 of [ETSI].

   Transport_error_count: 32 bits

      A count of the number of Transport_errors that occurred in the
      above sequence number interval.  A Transport_error occurs when an
      erroneous TS packet can not cannot be corrected within the MPEG TS
      stream. MPEG-2 TS, as
      defined in the section Section 5.2.2 of [ETSI].

   PCR_error_count: 32 bits

      A count of the number of PCR_errors that occurred in the above
      sequence number interval.  A PCR_error occurs if the primary clock
      reference (PCR) is not seen for more than 100ms 100 ms within the MPEG TS
      stream, MPEG-2
      TS, as defined in the section Section 5.2.2 of [ETSI].  The time interval
      between two consecutive PCR values should be no more than
      40ms. 40 ms.

   PCR_repetition_error_count: 32 bits

      A count of the number of PCR_repetition_errors that occurred in
      the above sequence number interval.  A PCR_repeition_error PCR_repetition_error occurs
      when the time interval between two consecutive PCR values is more
      than 40ms 40 ms within the MPEG TS stream,as MPEG-2 TS, as defined in the section Section 5.2.2 of
      [ETSI].

   PCR_discontinuity_indicator_error_count: 32 bits

      A count of the number of PCR_discontinuity_indicator_errors that
      occurred in the above sequence number interval.  A
      PCR_discontinuity_indicator_error occurs if the time interval
      between two consecutive PCR values is more than 100ms 100 ms within the
      MPEG TS stream,
      MPEG-2 TS, as defined in the section Section 5.2.2 of [ETSI].

   PCR_accuracy_error_count: 32 bits

      A count of the Number number of PCR_accuracy_errors that occurred in the
      above sequence number interval.  A PCR_accuracy_error occurs when
      the PCR accuracy of the selected program is outside the range of
      +/-500ns
      +/-500 ns within the MPEG TS stream,as MPEG-2 TS, as defined in the section Section 5.2.2 of
      [ETSI].

   PTS_error_count: 32 bits

      A count of the number of PTS_errors that occurred in the above
      sequence number interval.  A PTS_error occurs when the PTS
      repetition is more than 700ms 700 ms within the MPEG TS stream, MPEG-2 TS, as defined in the section
      Section 5.2.2 of[ETSI]. of [ETSI].  Note that the PTS is contained in the
      MPEG-2 TS stream and is used to aid the decoder in presenting the program
      on time, at the correct speed speed, and synchronized.

4.  SDP Signaling

   RFC 3611 defines the use of SDP (Session the Session Description Protocol) Protocol (SDP)
   [RFC4566] for signaling the use of RTCP XR blocks.  However  However, XR
   blocks MAY be used without prior signaling (See section (see Section 5 of RFC3611). RFC
   3611).

4.1.  SDP rtcp-xr-attrib rtcp-xr Attribute Extension

   This session augments the SDP attribute "rtcp-xr" defined in
   Section 5.1 of RFC 3611 by providing an additional value of
   "xr-format" to signal the use of the report block defined in this
   document.  The ABNF [RFC5234] syntax is as follows.

   xr-format =/  xr-tpid-block

   xr-tpid-block = "ts-psi-indep-decodability"

4.2.  Offer/Answer Usage

   When SDP is used in offer-answer Offer/Answer context, the SDP Offer/Answer usage
   defined in [RFC3611] for unilateral "rtcp-xr" attribute parameters
   applies.  For detailed usage of Offer/Answer for unilateral
   parameter,
   parameters, refer to section Section 5.2 of [RFC3611].

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 RFC 3611.

5.1.  New RTCP XR Block Type value Value

   This document assigns the block type value MTPID 22 in the IANA " RTP "RTP
   Control Protocol Extended Reports (RTCP XR) Block Type Registry " Registry" to
   the "MPEG2 "MPEG-2 Transport Stream PSI Independent PSI-Independent Decodability Statistics
   Metrics Block".

   [Note to RFC Editor: please replace MPITD with the IANA provided RTCP
   XR block type for this block.]

5.2.  New RTCP XR SDP Parameter

   This document also registers a the new parameter "ts-psi-indep-
   decodability" "ts-psi-
   indep-decodability" in the "RTP Control Protocol Extended Reports
   (RTCP XR) Session Description Protocol (SDP) Parameters Registry".

5.3.  Contact information Information for registrations Registrations

   The contact information for the registrations is:

   Qin Wu
                    sunseawq@huawei.com (sunseawq@huawei.com)
   101 Software Avenue, Yuhua District
   Nanjing, JiangSu Jiangsu  210012
   China

6.  Security Considerations

   There might be some relationship between reported error counters and
   contractual Service Level Agreements (SLA)s and hence (SLAs); hence, an attack (e.g.,
   RTP endpoints report fake information, reporting false data, or an attacker in the path modifies
   modifying the data being reported ) may reported) might deliberately corrupt these
   error counters fields and will result counters, resulting in financial implications for the network
   operator (either as a result of un-needed Performance unneeded performance metrics, or
   penalty charges for SLA failure).

   A solution to prevent such an attack is to apply an authentication
   and integrity protection framework for the RTCP XR report block.  This can
   be accomplished using the RTP profile that combines Secure RTP
   [RFC3711] and AVPF the Audio-Visual Profile with Feedback (AVPF) into SAVPF
   Secure AVPF (SAVPF) [RFC5124].

   Besides this, the proposed RTCP XR report block in this document introduces no other new
   security considerations beyond those described in [RFC3611].

7.  Acknowledgements

   Thanks to Ray van Brandenburg, Claire Bi, Colin Perkin, Perkins, Roni Even,
   Dan Romascanu, Ali Begen Begen, Alexey Melnikov, Bert Wijnen, Gonzalo
   Camarillo, Benoit Claise, and Alan Clark for useful review reviews and
   suggestions.

8.  References

8.1.  Normative References

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

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

   [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.

   [RFC3711]  Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K.
              Norrman, "The Secure Real-time Transport Protocol (SRTP)",
              RFC 3711, March 2004.

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

   [RFC5124]  Ott, J. and E. Carrara, "Extended Secure RTP Profile for
              Real-time Transport Control Protocol (RTCP)-Based Feedback
              (RTP/SAVPF)", RFC 5124, February 2008.

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

8.2.  Informative References

   [ISO-IEC.13818-1.2007]

   [ISO-IEC.13818-1.2013]
              International Organization for Standardization,
              "Information technology - Generic coding of moving
              pictures and associated audio information: Systems", ISO
              International Standard 13818-1, October 2007. May 2013.

   [RFC6390]  Clark, A. and B. Claise, "Guidelines for Considering New
              Performance Metric Development", BCP 170, RFC 6390,
              October 2011.

   [RFC6709]  Carpenter, B., Aboba, B., and S. Cheshire, "Design
              Considerations for Protocol Extensions", RFC 6709,
              September 2012.

   [RFC6776]  Clark, A. and Q. Wu, Q., "Measurement Identity and information Information
              Reporting
              using SDES item Using a Source Description (SDES) Item and XR an
              RTCP Extended Report (XR) Block", RFC 6776, August October 2012.

   [RFC6792]  Wu, Q., Hunt, G., and P. Arden, "Guidelines for Use of the
              RTP Monitoring Framework", RFC 6792, November 2012.

Authors' Addresses

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

   Email:

   EMail: rachel.huang@huawei.com

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

   Email:

   EMail: bill.wu@huawei.com

   Hitoshi Asaeda
   National Institute of Information and Communications Technology
   4-2-1 Nukui-Kitamachi
   Koganei, Tokyo  184-8795
   Japan

   Email:

   EMail: asaeda@nict.go.jp

   Glen Zorn
   Network Zen
   227/358 Thanon Sanphawut
   Bang Na, Bangkok  10260
   Thailand

   Phone: +66 (0) 909-201060
   Email: 8-1000-4155
   EMail: glenzorn@gmail.com