Network Working Group R. Huang Internet-Draft Q. Wu Intended status: Standards Track Huawei Expires: October 9, 2013 H. Asaeda NICT G. Zorn Network Zen April 7, 2013 RTP Control Protocol (RTCP) Extended Report (XR) Block for MPEG2 Transport Stream (TS) Program Specific Information (PSI) Independent Decodability Statistics Metrics reporting draft-ietf-xrblock-rtcp-xr-decodability-11 Abstract An MPEG2 Transport Stream (TS) is a standard container format used in the transmission and storage of multimedia data. Unicast/Multicast MPEG2 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 MPEG2 TS decodability statistics metrics related to transmissions of MPEG2 TS over RTP. The metrics specified in the RTCP XR Block are not dependent on Program specific information carried in MPEG TS. 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 October 9, 2013. Copyright Notice Copyright (c) 2013 IETF Trust and the persons identified as the document authors. All rights reserved. Huang, et al. Expires October 9, 2013 [Page 1] Internet-Draft RTCP XR TS Decodability April 2013 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 . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. MPEG2 Transport Stream Decodability Metrics . . . . . . . 3 1.2. RTCP and RTCP XR Reports . . . . . . . . . . . . . . . . . 3 1.3. Performance Metrics Framework . . . . . . . . . . . . . . 3 1.4. Applicability . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.1. Standards Language . . . . . . . . . . . . . . . . . . . . 4 3. MPEG2 TS PSI Independent Decodability Statistics Metrics Block . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4. SDP Signaling . . . . . . . . . . . . . . . . . . . . . . . . 7 4.1. SDP rtcp-xr-attrib Attribute Extension . . . . . . . . . . 8 4.2. Offer/Answer Usage . . . . . . . . . . . . . . . . . . . . 8 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 5.1. New RTCP XR Block Type value . . . . . . . . . . . . . . . 8 5.2. New RTCP XR SDP Parameter . . . . . . . . . . . . . . . . 8 5.3. Contact information for registrations . . . . . . . . . . 8 6. Security Considerations . . . . . . . . . . . . . . . . . . . 9 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 9 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9 8.1. Normative References . . . . . . . . . . . . . . . . . . . 9 8.2. Informative References . . . . . . . . . . . . . . . . . . 9 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 10 Huang, et al. Expires October 9, 2013 [Page 2] Internet-Draft RTCP XR TS Decodability April 2013 1. Introduction 1.1. MPEG2 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 Transport Streams [ISO-IEC.13818-1.2007]. 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 Transport Stream (TS) [ISO-IEC.13818-1.2007]. 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. 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 This block type allows a counts of MPEG 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. Huang, et al. Expires October 9, 2013 [Page 3] Internet-Draft RTCP XR TS Decodability April 2013 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 TS 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 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 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 including: o Transport Stream Synchronization Losses o Sync byte errors o Continuity count errors and continuous monitoring parameters necessary to ensure the continuous 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 implementations. For further information on these parameters, see [ETSI]. Note that when the report of this block spans across more than one measurement intervals [RFC6776], the count of the metrics (e.g., Sync byte errors, PCR errors )defined in [ETSI] may reflect a problem in the current or previous measurement interval. The MPEG2 TS PSI Independent Decodability Metrics Block has the following format: Huang, et al. Expires October 9, 2013 [Page 4] Internet-Draft RTCP XR TS Decodability April 2013 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 | Reserved | block length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SSRC of 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 (BT): 8 bits The MPEG2 TS PSI Independent Decodability Metrics Block is identified by the constant . Reserved: 8 bits These bits are reserved. They MUST be set to zero by senders and ignored by receivers (See [RFC6709] section 4.2). 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. Huang, et al. Expires October 9, 2013 [Page 5] Internet-Draft RTCP XR TS Decodability April 2013 SSRC of 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, as defined in 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, as defined in 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 TS stream - incorrect packet order, a packet occurs more than twice or a packet is lost,as defined in the 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 erroneous TS packet can not be corrected within the MPEG TS stream. as defined in the 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 within the MPEG TS Huang, et al. Expires October 9, 2013 [Page 6] Internet-Draft RTCP XR TS Decodability April 2013 stream, as defined in the section 5.2.2 of [ETSI]. The time interval between two consecutive PCR values should be no more than 40ms. 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 occurs when the time interval between two consecutive PCR values is more than 40ms within the MPEG TS stream,as defined in the 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 within the MPEG TS stream, as defined in the section 5.2.2 of [ETSI]. PCR_accuracy_error_count: 32 bits A count of the 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 within the MPEG TS stream,as defined in the 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 within the MPEG TS stream, as defined in the section 5.2.2 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 and synchronized. 4. SDP Signaling RFC 3611 defines the use of SDP (Session Description Protocol) [RFC4566] for signaling the use of RTCP XR blocks. However XR blocks MAY be used without prior signaling (See section 5 of RFC3611). Huang, et al. Expires October 9, 2013 [Page 7] Internet-Draft RTCP XR TS Decodability April 2013 4.1. SDP rtcp-xr-attrib 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. xr-format =/ xr-tpid-block xr-tpid-block = "ts-psi-indep-decodability" 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 of Offer/Answer for unilateral parameter, refer to 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 This document assigns the block type value MTPID in the IANA " RTP Control Protocol Extended Reports (RTCP XR) Block Type Registry " to the "MPEG2 Transport Stream 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 new parameter "ts-psi-indep- decodability" in the "RTP Control Protocol Extended Reports (RTCP XR) Session Description Protocol (SDP) Parameters Registry". 5.3. Contact information for registrations The contact information for the registrations is: Qin Wu sunseawq@huawei.com 101 Software Avenue, Yuhua District Nanjing, JiangSu 210012 China Huang, et al. Expires October 9, 2013 [Page 8] Internet-Draft RTCP XR TS Decodability April 2013 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, Roni Even, Dan Romascanu, Ali Begen and Alan Clark for useful review 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., "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. [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session Description Protocol", RFC 4566, July 2006. 8.2. Informative References [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. [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, Huang, et al. Expires October 9, 2013 [Page 9] Internet-Draft RTCP XR TS Decodability April 2013 September 2012. [RFC6776] Wu, Q., "Measurement Identity and information Reporting using SDES item and XR Block", RFC 6776, August 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: 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 Network Zen 227/358 Thanon Sanphawut Bang Na, Bangkok 10260 Thailand Phone: +66 (0) 909-201060 Email: glenzorn@gmail.com Huang, et al. Expires October 9, 2013 [Page 10]