wdiff rfc6990.original rfc6990.txt

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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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