Network Working Group R. Huang
Internet-Draft Q. Wu
Intended status: Standards Track Huawei
Expires: June 20, 2013 H. Asaeda
NICT
G. Zorn, Ed.
Network Zen
December 17, 2012

RTP Control Protocol (RTCP) Extended Report (XR) Block for MPEG Transport Stream Decodability Statistics Metric reporting
draft-ietf-xrblock-rtcp-xr-decodability-03

Abstract

An MPEG Transport Stream (TS) is a standard container format used in the transmission and storage of multimedia data. Unicast/Multicast/ Broadcast MPEG-TS over RTP is widely deployed in IPTV systems. This document defines an RTP Control Protocol (RTCP) Extended Report (XR) Block that allows the reporting of MPEG Transport Stream decodability statistics metrics related to transmissions of MPEG-TS over RTP.

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 June 20, 2013.

Copyright Notice

Copyright (c) 2012 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 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

1.1. MPEG 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 MPEG-2 Transport Streams [ISO-IEC.13818-1.2007]. The tests and corresponding indicators are grouped according to priority:

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 Freidman, et al. [RFC3611] for use with Transport Stream (TS) [ISO-IEC.13818-1.2007]. The new block type supports reporting of the number of occurrences of each indicator in the first and second priorities; third priority indicators are not supported.

1.2. RTCP and RTCP XR 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 Performance Metrics Framework [RFC6390] provides guidance on the definition and specification of performance metrics. The RTP Monitoring Architectures [RFC6792] provides guideline for 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 [RFC6390].

1.4. Applicability

These metrics are applicable to any type of RTP application that uses the MPEG-TS standard format for multimedia data; for example, MPEG4 TS content over RTP. This new block type can be useful for measuring content stream or TS quality by checking TS header information [ETSI] and identifying the existence, and characterizing the severity, of bitstream packetization problems which may affect users' perception of a service delivered over RTP; it may also be useful for verifying the continued correct operation of an existing system management tool.

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. MPEG Transport Stream Decodability Statistics Metric Report Block

    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=TSDM   |    Reserved   |         block length          |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                     SSRC of source                            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |          begin_seq            |             end_seq           |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                         Number of TSs                         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                      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            |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   |                       PTS_error_count                         |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

This block reports MPEG transport stream 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 defines eight metrics based on ETSI TR 101 290. Information is reported about basic monitoring parameters necessary to ensure that the TS can be decoded including:



[ETSI].

The MPEG-TS Decodability Metrics Block has the following format:

and continuous monitoring parameters including:

The other parameters are ignored since they do not apply to all MPEG implementations. For further information on these parameters, see

block type (BT): 8 bits


A TR 101 290 MPEG-TS decodability metrics report block is identified by the constant <TSDM>.

Reserved: 8 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 SHOULD be ignored by the receiver.

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 of source: 32 bits


As defined in Section 4.1 of RFC 3611.

begin_seq: 16 bits


As defined in Section 4.1 of RFC 3611.

end_seq: 16 bits


As defined in Section 4.1 of RFC 3611.

Number of TSs: 32 bits


Number of TS in the above sequence number interval.

TS_sync_loss_count: 32 bits


Number of TS_sync_loss errors in the above sequence number interval. It is calculated based on the occurrence of errors for “TS_sync_loss”parameter defined in the table 5.2.1 of ETSI TR 101 290 (See section 5.5.1 of ETSI TR 101 290).

Sync_byte_error_count: 32 bits


Number of sync_byte_errors in the above sequence number interval. It is calculated in the same way as TS_sync_loss_count, i.e.,based on the occurrence of errors for “Sync_byte_error”parameter defined in the table 5.2.1 of ETSI TR 101 290.

Continuity_count_error_count: 32 bits


Number of Continuity_count_errors in the above sequence number interval. Simiarly, it is calculated based on the occurrence of errors for “Continuity_count_error”parameter defined in the table 5.2.1 of ETSI TR 101 290.

Transport_error_count: 32 bits


Number of Transport_errors in the above sequence number interval. Simiarly, it is calculated based on the occurrence of errors for "Transport_error" parameter defined in the table 5.2.2 of ETSI TR 101 290.

PCR_error_count: 32 bits


Number of PCR_errors in the above sequence number interval. Simiarly, it is calculated based on the occurrence of errors for “PCR_error”parameter defined in the table 5.2.2 of ETSI TR 101 290.

PCR_repetition_error_count: 32 bits


Number of PCR_repetition_errors in the above sequence number interval. Simiarly, it is calculated based on the occurrence of errors for “PCR_repetition_error”parameter defined in the table 5.2.2 of ETSI TR 101 290.

PCR_discontinuity_indicator_error_count: 32 bits


Number of PCR_discontinuity_indicator_errors in the above sequence number interval. Simiarly, it is calculated based on the occurrence of errors for “PCR_discontinuity_indicator_error”parameter defined in the table 5.2.2 of ETSI TR 101 290.

PTS_error_count: 32 bits


Number of PTS_errors in the above sequence number interval. Simiarly, it is calculated based on the occurrence of errors for “PTS_error”parameter defined in the table 5.2.2 of ETSI TR 101 290.

4. SDP Signaling

RFC 3611 defines the use of SDP (Session Description Protocol) [RFC4566] for signaling the use of RTCP XR blocks. XR blocks MAY be used without prior signaling.

4.1. SDP rtcp-xr-attrib Atrribute Extension

xr-format =/  ts-decodability-metrics

      ts-decodability-metrics = "ts-decodability-metrics" 

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.

4.2. Offer/Answer Usage

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

5. IANA Considerations

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

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 ofRFC 3611.

This document assigns one new block type value in the RTCP XR Block Type Registry: [RFC4566] parameters for the "rtcp-xr" attribute in the RTCP XR SDP Parameter Registry:

The contact information for the registrations is:

This document also registers one SDP

6. Security Considerations

This proposed RTCP XR report block introduces no new security considerations beyond those described in RFC 3611.

7. Acknowledgements

Thanks to Ray van Brandenburg, Claire Bi,Colin Perkin and Dan Romascanufor useful review and suggestions.

8. References

8.1. Normative References

[RFC3550] Schulzrinne, H., "RTP: A Transport Protocol for Real-Time Applications", RFC 3550, July 2003.
[RFC3611] Friedman, T., Caceres, R. and A. Clark, "RTP Control Protocol Extended Reports (RTCP XR)", RFC 3611, November 2003.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC4566] Handley, M., Jacobson, V. and C. Perkins, "SDP: Session Description Protocol", RFC 4566, July 2006.
[ETSI] ETSI, "Digital Video Broadcasting (DVB); Measurement guidelines for DVB systems", Technical Report TR 101 290, 2001.

8.2. Informative References

[RFC6792] Wu, Q., Hunt, G. and P. Arden, "Guidelines for Use of the RTP Monitoring Framework ", RFC 6792, November 2012.
[RFC6390] Clark, A. and B. Claise, "Guidelines for Considering New Performance Metric Development", BCP 170, RFC 6390, October 2011.
[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.

Authors' Addresses

Rachel Huang Huawei 101 Software Avenue, Yuhua District Nanjing, 210012 China EMail: rachel.huang@huawei.com
Qin Wu Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 China 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: asaeda@nict.go.jp
Glen Zorn (editor) Network Zen 227/358 Thanon Sanphawut Bang Na, Bangkok 10260 Thailand Phone: +66 (0) 909-201060 EMail: glenzorn@gmail.com