Network Working GroupInternet Engineering Task Force (IETF) J. TongInternet-DraftRequest for Comments: 7380 C. Bi, Ed.Intended status:Category: Standards Track China TelecomExpires: February 11, 2015ISSN: 2070-1721 R. EvenGesher Erove LtdQ. Wu, Ed. R. Huang HuaweiAugust 10,November 2014 RTP Control Protocol (RTCP) Extended Report (XR) Block for MPEG2 Transport Stream (TS) Program Specific Information (PSI) Decodability Statistics Metricsreporting draft-ietf-xrblock-rtcp-xr-psi-decodability-07Reporting Abstract An MPEG2 Transport Stream (TS) is a standard container format used in the transmission and storage of multimedia data.Unicast/MulticastUnicast/multicast MPEG2 TS over RTP is widely deployed in IPTV systems. This document defines an RTP Control Protocol (RTCP) Extended Report (XR)Blockblock that allows the reporting of MPEG2 TS decodability statistics metrics related to transmissions of MPEG2 TS over RTP. The metrics specified in the RTCP XRBlockblock are related to Program Specific Information (PSI) carried in MPEG TS. Status of This Memo ThisInternet-Draftissubmitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documentsan Internet Standards Track document. This document is a product of the Internet Engineering Task Force (IETF).Note that other groups may also distribute working documents as Internet-Drafts. The listIt represents the consensus ofcurrent Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents validthe IETF community. It has received public review and has been approved fora maximumpublication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 ofsix monthsRFC 5741. Information about the current status of this document, any errata, and how to provide feedback on it may beupdated, replaced, or obsoleted by other documentsobtained atany 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 February 11, 2015.http://www.rfc-editor.org/info/rfc7380. Copyright Notice Copyright (c) 2014 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. . . . . . . . . . . . . . . . . . . . . . . . 2....................................................3 1.1. MPEG2 Transport Stream Decodability Metrics. . . . . . . 2................3 1.2. RTCP and RTCP XR Reports. . . . . . . . . . . . . . . . 3...................................3 1.3. Performance Metrics Framework. . . . . . . . . . . . . . 3..............................3 1.4. Applicability. . . . . . . . . . . . . . . . . . . . . . 3..............................................3 2. Terminology. . . . . . . . . . . . . . . . . . . . . . . . . 3.....................................................4 2.1. Standards Language. . . . . . . . . . . . . . . . . . . 4.........................................4 3. MPEG2 TS PSI Decodability Statistics Metrics Block. . . . . 4..............4 4. SDP Signaling. . . . . . . . . . . . . . . . . . . . . . . . 8...................................................8 4.1. SDP rtcp-xr-attrib Attribute Extension. . . . . . . . . 8.....................8 4.2. Offer/Answer Usage. . . . . . . . . . . . . . . . . . . 8.........................................8 4.3. Usage Outside of Offer/Answer. . . . . . . . . . . . . . 8..............................8 5. IANA Considerations. . . . . . . . . . . . . . . . . . . . . 8.............................................9 5.1. New RTCP XR Block Typevalue . . . . . . . . . . . . . . 8Value ...............................9 5.2. New RTCP XR SDP Parameter. . . . . . . . . . . . . . . . 9..................................9 5.3. ContactinformationInformation forregistrations . . . . . . . . . . 9Registrations ......................9 6. Security Considerations. . . . . . . . . . . . . . . . . . . 9.........................................9 7. References. . . . . . . . . . . . . . . . . . . . . . . . . 9......................................................9 7.1. Normative References. . . . . . . . . . . . . . . . . . 9.......................................9 7.2. Informative References. . . . . . . . . . . . . . . . . 10....................................10 Authors' Addresses. . . . . . . . . . . . . . . . . . . . . . . 10.................................................11 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:oFirstpriority -priority: Necessary for decodability (basic monitoring)oSecondpriority -priority: Recommended for continuous or periodic monitoringoThirdpriority -priority: Recommended for application-dependent monitoring This memo defines a new block type for use with MPEG2 TransportStream (TS) [ISO-IEC.13818-1.2007],Streams [ISO-IEC.13818-1.2007] to augment those defined in [RFC3611]. The new block type supports reporting of the number of occurrences of each Program Specific Information (PSI) indicator in the first and second priorities listedby [ETSI] sectionsin Sections 5.2.1 and5.2.2 respectively. Third5.2.2, respectively, of [ETSI]. The third priority indicators are not supported. The metrics defined here supplement information from thePSI- independentPSI-Independent Decodability Statistics Metrics Block [RFC6990]. 1.2. RTCP and RTCP XR Reports The use of RTCP for reporting is defined in [RFC3550]. [RFC3611] defines 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 guidelines for RTCP XRreportingblock formats. 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 MPEG2 TS standard format for multimedia data, for example, MPEG4 over MPEG2 TS over RTP. This new block type can be useful for measuring content stream or TS quality by checking TS header information [ETSI] and identifying theexistence, andexistence (and characterizing theseverity,severity) of bitstream packetization problemswhichthat 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. MPEG2 TS PSI Decodability Statistics Metrics Block ETSI TR101290101 290 [ETSI] generally defines indicators related to errorevents, whileevents whereas the XR block defined in this document contains counts of occurrences of the [ETSI] indicators. The block defined in this document reports MPEG2 TS PSI decodability statistics metrics beyond the information carried in the standard RTCP packet format and PSI-independentIndependent Decodability Statistics Metrics Block [RFC6990], which are measured at the receiving end of the RTP stream. It contains counts of seven metrics defined in ETSI TR101290101 290 [ETSI]. Information is reported about basic monitoring parameters necessary to ensure that the TS can bedecodeddecoded, including: o Program Association Table (PAT) errors oPAT 2PAT2 errors o Program Map Table (PMT) errors oPMT 2PMT2 errors o Packet Identifier (PID) errorsandInformation is also reported about continuous monitoring parameters necessary to ensurethecontinuousdecodingdecoding, including: o Cyclic Redundancy Check (CRC) errors o Conditional Access Table (CAT) errors In these parameters,PAT 2PAT2 errors andPMT 2PMT2 errors are actually replacements for and improvements on PAT errors and PMTerrors respectivelyerrors, respectively, and are therefore preferred in future implementations. In addition, measurement results for some of these parameters (e.g., PAT errors or PMT errors) may be different based on whether scrambling is employed. The other parameters defined in[ETSI]Section 5 of [ETSI] are ignored since they do not apply to all MPEG2 implementations. For further detailed information on these parameters, see [ETSI]. The MPEG2 TS PSI 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=MTPDBT=32 | Reserved | block length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | SSRC of source | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | begin_seq | end_seq | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PAT_error_count | PAT_error_2_count | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PMT_error_count | PMT_error_2_count | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | PID_error_count | CRC_error_count | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | CAT_error_count | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ block type (BT): 8 bits The MPEG2 TS PSI Decodability Metrics Block is identified by the constant<MTPD>.32;. Reserved: 8 bits These bits are reserved. They MUST be set to zero by senders ignored by receivers(See [RFC6709] section 4.2).(see Section 4.2 of [RFC6709]). block length: 16 bits The constant 6, in accordance with the definition of this field in Section 3 ofRFC 3611.[RFC3611]. The block MUST be discarded if the block length is set to a different value.SSRCSynchronization Source (SSRC) of source: 32 bits As defined in Section 4.1 ofRFC 3611.[RFC3611]. begin_seq: 16 bits As defined in Section 4.1 ofRFC 3611.[RFC3611]. end_seq: 16 bits As defined in Section 4.1 ofRFC 3611.[RFC3611]. PAT_error_count: 16 bits A count of the number of PAT errors that occurred in the above sequence number interval. Theprogram association tableProgram Association Table (PAT) is the only packet withpacket IDPacket Identifier (PID)0x 0000.0x0000. A PAT error occurswhen:when (1) a packet with PID 0x0000 does not occur at least every 0.5 seconds,or(2) a packet with PID 0x0000 does not containatable_id 0x00 (i.e., a PAT), or(3)Scrambling_control_field(3) the Scrambling_control_field in the TS packet header is not 00 for a packet with PID 0x0000. SeesectionSection 5.2.1 of [ETSI]. Every program within the MPEG TS stream is listed in the PAT; if it is missing, then no programs can be decoded. The measured value is an unsigned value. If the measurement is unavailable, then the value 0xFFFF MUST be reported.As indicated in theNOTE 1 of the table inthe sectionSection 5.2.1 ofTR101.290, TR 101.290[ETSI] recommends using PAT_error_2_count. Upon reception,Ifif PAT_error_2_count is available (that is, other than 0xFFFF), then receivers MUST ignore PAT_error_count. PAT_error_2_count: 16 bits A count of the number of PAT2 errors that occurred in the above sequence number interval. A PAT2 error occurswhen:when (1) a packet with PID 0x0000 containing table_id 0x00 does not occur at least every 0.5seconds,orseconds, (2) a packet with PID 0x0000 contains a table with a table_id other than 0x00, or (3) the Scrambling_control_field in the TS packet header is not 00 for a packet with PID 0x0000. SeesectionSection 5.2.1 of [ETSI]. The measured value is an unsigned value. If the measurement is unavailable, then the value 0xFFFF MUST be reported. PMT_error_count: 16 bits A count of the number ofPMT_errorsPMT errors that occurred in the above sequence number interval. A PMT_error occurswhen:when (1) a packet containing a table with table_id0x02(i.e.,a0x02 (i.e., a PMT) does not occur at least every0.5s0.5 seconds on the PID that is referred to in thePAT, or(2)PAT or (2) the Scrambling_control_field in the TS packet header is not 00 for all packets with PID containing a table with table_id 0x02(i.e.(i.e., a PMT). Seethe sectionSection 5.2.1 of [ETSI]. The measured value is an unsigned value. If the measurement is unavailable, the value 0xFFFF MUST be reported.As indicated in theNOTE 2 of the table inthe sectionSection 5.2.1 ofTR101.290, TR 101.290[ETSI] recommends using PMT_error_2_count. Upon reception,Ifif PMT_error_2_count is available (that is, other than 0xFFFF), then receivers MUST ignore PMT_error_count. PMT_error_2_count: 16 bits A count of the number of PMT2 errors that occurred in the above sequence number interval. A PMT2_error occurswhen:when (1) a packet containing table_id0x02(i.e.,a0x02 (i.e., a PMT) does not occur at least every0.5s0.5 seconds on each program_map_PIDwhichthat is referred to in thePAT,PAT or (2) the Scrambling_control_field in the TS packet header is not 00 for all packets containing a table with table_id 0x02(i.e.(i.e., a PMT) on each program_map_PIDwhichthat is referred to in the PAT. SeesectionSection 5.2.1 of [ETSI]. The measured value is an unsigned value. If the measurement is unavailable, then the value 0xFFFF MUST be reported. PID_error_count: 16 bits A count of the number ofPID_errorsPID errors that occurred in the above sequence number interval. A PID error occurs when no data stream is present corresponding to a given PID. This may be caused by multiplexing or demultiplexing, then remultiplexing. SeesectionSection 5.2.1 of [ETSI]. The measured value is an unsigned value. If the measurement is unavailable, then the value 0xFFFF MUST be reported. CRC_error_count: 16 bits A count of the number ofCRC_errorsCRC errors that occurred in the above sequence number interval. A CRC_error occurs if data corruption occurred in any of the following tables -- CAT, PAT, PMT, Network Information Table (NIT), Event Information Table (EIT), Bouquet Association Table (BAT), Service Description Table(SDT)(SDT), or Time Offset Table (TOT), as defined inthe sectionSection 5.2.2 of [ETSI]. The measured value is an unsigned value. If the measurement is unavailable, then the value 0xFFFF MUST be reported. CAT_error_count: 16 bits A count of the number ofCAT_errorsCAT errors that occurred in the above sequence number interval. A CAT_error occurswhen:when (1) a packet with PID 0x0001 contains a table with a table_id other than0x01(i.e.,not0x01 (i.e., not aCAT),CAT) or (2)Aa packet does not contain a table with table_id = 0x01(i.e.(i.e., a CAT) when scrambling is employed((i.e., scrambling_control field(i.e., the Scrambling_control_field is set as a value other than00)).00). Seethe sectionSection 5.2.2 of [ETSI]. The measured value is an unsigned value. If the measurement is unavailable, then the value 0xFFFF MUST be reported. Reserved: 16 bits These bits are reserved. They MUST be set to zero by senders ignored by receivers(See [RFC6709] section 4.2).(see Section 4.2 of [RFC6709]). 4. SDP SignalingRFC 3611[RFC3611] defines the use ofSDP (Sessionthe Session DescriptionProtocol)Protocol (SDP) [RFC4566] for signaling the use of RTCP XR blocks.HoweverHowever, XR blocks MAY be used without prior signaling(See section(see Section 5 ofRFC3611).[RFC3611]). 4.1. SDP rtcp-xr-attrib Attribute Extension This session augments the SDP attribute "rtcp-xr" defined in Section 5.1 ofRFC 3611[RFC3611] 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-tpd-block xr-tpd-block = "ts-psi-decodability" 4.2. Offer/Answer Usage When SDP is used inoffer-answerOffer/Answer context, the SDP Offer/Answer usage defined in [RFC3611] for unilateral "rtcp-xr" attribute parameters applies. For detailed usage of Offer/Answer for unilateralparameter,parameters, refer tosectionSection 5.2 of [RFC3611]. 4.3. Usage Outside of Offer/Answer For usage outside ofOffer/Answer,referOffer/Answer, refer tosectionSection 5.3 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 ofRFC 3611.[RFC3611]. 5.1. New RTCP XR Block TypevalueValue This document assigns the block type valueMTPD32 "MPEG2 Transport Stream PSI Decodability Statistics Metrics Block" in the "RTCP XR Block Type" subregistry of the IANA" RTP"RTP Control Protocol Extended Reports (RTCP XR) Block TypeRegistry " to the "MPEG2 Transport Stream PSI Decodability Statistics Metrics Block". [Note to RFC Editor: please replace MTPD with the IANA provided RTCP XR block type for this block.]Registry". 5.2. New RTCP XR SDP Parameter This document also registers a new parameter "ts-psi-decodability" in the "RTCP XR SDP Parameters" subregistry of the "RTP Control Protocol Extended Reports (RTCP XR) Session Description Protocol (SDP) Parameters Registry". 5.3. ContactinformationInformation forregistrationsRegistrations The contact information for the registrations is: RAI Area Directors <rai-ads@tools.ietf.org> 6. Security Considerations This proposed RTCP XRreportblock introduces no new security considerations beyond those described in [RFC3611] and [RFC6990]. 7. References 7.1. Normative References [ETSI] ETSI, "Digital Video Broadcasting (DVB); Measurement guidelines for DVB systems",Technical ReportETSI TR 101 290,2001.June 2014. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March1997.1997, <http://www.rfc-editor.org/info/rfc2119>. [RFC3550] Schulzrinne, H., "RTP: A Transport Protocol for Real-Time Applications", RFC 3550, July2003.2003, <http://www.rfc-editor.org/info/rfc3550>. [RFC3611] Friedman, T., Caceres, R., and A. Clark, "RTP Control Protocol Extended Reports (RTCP XR)", RFC 3611, November2003.2003, <http://www.rfc-editor.org/info/rfc3611>. [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session Description Protocol", RFC 4566, July2006.2006, <http://www.rfc-editor.org/info/rfc4566>. [RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", STD 68, RFC 5234, January 2008, <http://www.rfc-editor.org/info/rfc5234>. 7.2. Informative References [ISO-IEC.13818-1.2007]International Organization for Standardization,ISO/IEC, "Information technology - Generic coding of moving pictures and associated audioinformation:information - Part 1: Systems", ISO International Standard 13818-1,October 2007.2013. [RFC6390] Clark, A. and B. Claise, "Guidelines for Considering New Performance Metric Development", BCP 170, RFC 6390, October2011.2011, <http://www.rfc-editor.org/info/rfc6390>. [RFC6709] Carpenter, B., Aboba, B., and S. Cheshire, "Design Considerations for Protocol Extensions", RFC 6709, September2012.2012, <http://www.rfc-editor.org/info/rfc6709>. [RFC6792] Wu, Q., Hunt, G., and P. Arden, "Guidelines for Use of the RTP Monitoring Framework", RFC 6792, November2012.2012, <http://www.rfc-editor.org/info/rfc6792>. [RFC6990] Wu, Q., "RTP Control Protocol (RTCP) Extended Report (XR) Block for MPEG2 Transport Stream (TS) Program Specific Information (PSI) Independent Decodability Statistics Metrics reporting", RFC 6990, May2013.2013, <http://www.rfc-editor.org/info/rfc6990>. Authors' Addresses Jiangang Tong Shanghai ResearchInstitureInstitute of China Telecom Corporation LimitedNo.1835,SouthNo. 1835, South Pudong Road Shanghai 200122 ChinaEmail:EMail: tongjg@sttri.com.cn Claire Bi (editor) Shanghai Research Institure of China Telecom Corporation LimitedNo.1835,SouthNo. 1835, South Pudong Road Shanghai 200122 ChinaEmail:EMail: bijy@sttri.com.cn Roni EvenGesher Erove LtdHuawei 14 David Hamelech Tel Aviv 64953 IsraelEmail: ron.even.tlv@gmail.comEMail: roni.even@mail01.huawei.com Qin Wu (editor) Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 ChinaEmail:EMail: bill.wu@huawei.com Rachel Huang Huawei 101 Software Avenue, Yuhua District Nanjing, Jiangsu 210012 ChinaEmail:EMail: rachel.huang@huawei.com