RTP Control Protocol (RTCP) Extended Report (XR) Block for MPEG Transport Stream (TS) Program Specific Information (PSI) Independent Decodability Statistics Metric reporting

The European Telecommunications Standards Institute (ETSI) has defined a set of syntax and information consistency tests and corresponding indicators that are recommended for the monitoring of MPEG-2 Transport Streams . The tests and corresponding indicators are grouped according to priority: First priority - Necessary for de-codability (basic monitoring) Second priority - Recommended for continuous or periodic monitoring Third priority - Recommended for application-dependant monitoring This memo is based on information consistency tests and resulting indicators defined by ETSI and defines a new block type to augment those defined in Freidman, et al. for use with MPEG Transport Stream (TS) . The new block type supports reporting of the number of occurrences of each Program Specific Information (PSI) Independent indicator in the first and second priorities; third priority indicators are not supported.

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

The Performance Metrics Framework [RFC6390] provides guidance on the definition and specification of performance metrics. The RTP Monitoring Architectures 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 and the Performance Metrics Framework .

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 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.

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.

This block reports MPEG TS 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 describes eight metrics specified in ETSI TR 101 290. Information is reported about basic monitoring parameters necessary to ensure that the TS can be decoded including: Transport Stream Synchronization Losses Sync byte errors Continuity count errors and continuous monitoring parameters necessary to ensure the continuous decoding including: Transport errors Program Clock Reference (PCR) errors PCR repetition errors PCR discontinuity indicator errors PCR accuracy errors Presentation Time Stamp (PTS) errors The other parameters are ignored since they do not apply to all MPEG implementations. For further information on these parameters, see . The MPEG-TS PSI Independent 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=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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PCR_accuracy_error_count | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PTS_error_count | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ The MPEG-TS PSI Independent Decodability Metrics Block is identified by the constant <MPID>. These bits are reserved. They MUST be set to zero by senders ignored by receivers (See section 4.2). The constant 12, 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. As defined in Section 4.1 of RFC 3611. As defined in Section 4.1 of RFC 3611. As defined in Section 4.1 of RFC 3611. Number of TS in the above sequence number interval. 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 section 5.2.1 of ETSI TR 101 290 (See section 5.5.1 of ETSI TR 101 290). 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 section 5.2.1 of ETSI TR 101 290. 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 section 5.2.1 of ETSI TR 101 290. 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 section 5.2.2 of ETSI TR 101 290. 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 section 5.2.2 of ETSI TR 101 290. 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 section 5.2.2 of ETSI TR 101 290. 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 section 5.2.2 of ETSI TR 101 290. Number of PCR_accuracy_errors in the above sequence number interval. Simiarly, it is calculated based on the occurrence of errors for “PCR_accuracy_error”parameter defined in the section 5.2.2 of ETSI TR 101 290. 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 section 5.2.2 of ETSI TR 101 290.

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

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.

xr-format =/ xr-nptd-block xr-nptd-block = "non-psi-ts-decodability"

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

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 the block type value MPID in the IANA " RTP Control Protocol Extended Reports (RTCP XR) Block Type Registry " to the " MPEG Transport Stream PSI Independent Decodability Statistics Metric Block". [Note to RFC Editor: please replace MPID with the IANA provided RTCP XR block type for this block.]

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

The contact information for the registrations is:

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

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

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