RTCP XR Report Block for TS Decodability Statistics Metric reporting
draft-huang-xrblock-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

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Table of Contents

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

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]by checking TS header information. This new block type can be useful for identifying the existence, and characterizing 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

 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    |      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                            |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

This block reports decodability statistics metric beyond the information carried in the standard RTCP packet format. Information is recorded about basic monitoring parameters necessary to ensure that the TS can be decoded including the number of Transport Stream Synchronization Losses, Sync byte errors, Continuity count errors, and continuous monitoring parameters including 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 real time application quality monitoring.

Note that this metric report block is not only applicable to MPEG-2 transport streams[RFC2250],but also applicable to any other Transport Streams that adopt other audio and video codec.

The Decodability Metrics Block has the following format:

block type (BT): 8 bits

A TR 101 290 decodability metrics report block is identified by the constant <TDM>.

rvd: 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 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.

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

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

   xr-format = decodability-metrics

      decodability-metrics = "decodability-metrics" 

One new parameter is 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]: RFC 3611 [RFC3611] for a detailed description and the full syntax of the "rtcp-xr" attribute.

5. IANA Considerations

Rachel Huang
Rachel@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 of [RFC3611].

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

The contact information for the registrations is:

• Name:

  TDM

  Long Name:

  TR 101 290 Decodability Metrics

  Value

  <TDM>

  Reference:

  section 3
  
  

This document also registers one SDP

• • “decodability-metrics”

6. Security Considerations

This proposed RTCP XR report block introduces no new security considerations beyond those described in [RFC3611].

7. References

7.1. Normative References

7.2. Informative References

Authors' Addresses