idnits 2.17.1 draft-ietf-xrblock-rtcp-xr-qoe-10.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year == Line 67 has weird spacing: '...o/video per S...' == Line 314 has weird spacing: '...o/video per S...' -- The document date (June 24, 2013) is 3952 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Missing Reference: 'RFCXXXX' is mentioned on line 978, but not defined == Unused Reference: 'RFC5234' is defined on line 738, but no explicit reference was found in the text -- Possible downref: Non-RFC (?) normative reference: ref. 'ATSC' ** Obsolete normative reference: RFC 4566 (Obsoleted by RFC 8866) ** Obsolete normative reference: RFC 5226 (Obsoleted by RFC 8126) Summary: 2 errors (**), 0 flaws (~~), 5 warnings (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group A. Clark 3 Internet-Draft Telchemy 4 Intended status: Standards Track Q. Wu 5 Expires: December 26, 2013 Huawei 6 R. Schott 7 Deutsche Telekom 8 G. Zorn 9 Network Zen 10 June 24, 2013 12 RTP Control Protocol (RTCP) Extended Report (XR) Blocks for MoS Metric 13 Reporting 14 draft-ietf-xrblock-rtcp-xr-qoe-10 16 Abstract 18 This document defines an RTP Control Protocol (RTCP) Extended Report 19 (XR) Block including two new segment types and associated SDP 20 parameters that allow the reporting of MoS Metrics for use in a range 21 of RTP applications. 23 Status of this Memo 25 This Internet-Draft is submitted in full conformance with the 26 provisions of BCP 78 and BCP 79. 28 Internet-Drafts are working documents of the Internet Engineering 29 Task Force (IETF). Note that other groups may also distribute 30 working documents as Internet-Drafts. The list of current Internet- 31 Drafts is at http://datatracker.ietf.org/drafts/current/. 33 Internet-Drafts are draft documents valid for a maximum of six months 34 and may be updated, replaced, or obsoleted by other documents at any 35 time. It is inappropriate to use Internet-Drafts as reference 36 material or to cite them other than as "work in progress." 38 This Internet-Draft will expire on December 26, 2013. 40 Copyright Notice 42 Copyright (c) 2013 IETF Trust and the persons identified as the 43 document authors. All rights reserved. 45 This document is subject to BCP 78 and the IETF Trust's Legal 46 Provisions Relating to IETF Documents 47 (http://trustee.ietf.org/license-info) in effect on the date of 48 publication of this document. Please review these documents 49 carefully, as they describe your rights and restrictions with respect 50 to this document. Code Components extracted from this document must 51 include Simplified BSD License text as described in Section 4.e of 52 the Trust Legal Provisions and are provided without warranty as 53 described in the Simplified BSD License. 55 Table of Contents 57 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 58 1.1. MoS Metrics Report Block . . . . . . . . . . . . . . . . . 4 59 1.2. RTCP and RTCP XR Reports . . . . . . . . . . . . . . . . . 4 60 1.3. Performance Metrics Framework . . . . . . . . . . . . . . 4 61 1.4. Applicability . . . . . . . . . . . . . . . . . . . . . . 4 62 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 63 2.1. Standards Language . . . . . . . . . . . . . . . . . . . . 5 64 3. MoS Metrics Block . . . . . . . . . . . . . . . . . . . . . . 6 65 3.1. Metric Block Structure . . . . . . . . . . . . . . . . . . 6 66 3.2. Definition of Fields in MoS Metrics Block . . . . . . . . 7 67 3.2.1. Single Stream audio/video per SSRC Segment . . . . . 8 68 3.2.2. Multi-Channel audio per SSRC Segment . . . . . . . . . 9 69 4. SDP Signaling . . . . . . . . . . . . . . . . . . . . . . . . 10 70 4.1. SDP rtcp-xr-attrib Attribute Extension . . . . . . . . . . 11 71 4.2. Offer/Answer Usage . . . . . . . . . . . . . . . . . . . . 12 72 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14 73 5.1. New RTCP XR Block Type value . . . . . . . . . . . . . . . 14 74 5.2. New RTCP XR SDP Parameter . . . . . . . . . . . . . . . . 14 75 5.3. The SDP calgextmap Attribute . . . . . . . . . . . . . . . 14 76 5.4. New registry of calculation algorithms . . . . . . . . . . 15 77 6. Security Considerations . . . . . . . . . . . . . . . . . . . 16 78 7. Authors . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 79 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 16 80 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 17 81 9.1. Normative References . . . . . . . . . . . . . . . . . . . 17 82 9.2. Informative References . . . . . . . . . . . . . . . . . . 17 83 Appendix A. Example of User Quality of Experience Evaluation 84 for video stream . . . . . . . . . . . . . . . . . . 19 85 Appendix B. Metrics represented using RFC6390 Template . . . . . 20 86 Appendix C. Change Log . . . . . . . . . . . . . . . . . . . . . 22 87 C.1. draft-ietf-xrblock-rtcp-xr-qoe-10 . . . . . . . . . . . . 22 88 C.2. draft-ietf-xrblock-rtcp-xr-qoe-09 . . . . . . . . . . . . 23 89 C.3. draft-ietf-xrblock-rtcp-xr-qoe-08 . . . . . . . . . . . . 23 90 C.4. draft-ietf-xrblock-rtcp-xr-qoe-07 . . . . . . . . . . . . 23 91 C.5. draft-ietf-xrblock-rtcp-xr-qoe-06 . . . . . . . . . . . . 23 92 C.6. draft-ietf-xrblock-rtcp-xr-qoe-04 . . . . . . . . . . . . 23 93 C.7. draft-ietf-xrblock-rtcp-xr-qoe-03 . . . . . . . . . . . . 23 94 C.8. draft-ietf-xrblock-rtcp-xr-qoe-02 . . . . . . . . . . . . 24 95 C.9. draft-ietf-xrblock-rtcp-xr-qoe-01 . . . . . . . . . . . . 24 96 C.10. draft-ietf-xrblock-rtcp-xr-qoe-00 . . . . . . . . . . . . 24 97 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 24 99 1. Introduction 101 1.1. MoS Metrics Report Block 103 This document defines a new block type to augment those defined in 104 [RFC3611], for use in a range of RTP applications. 106 The new block type provides information on media quality using one of 107 several standard metrics (i.e.,Mean Opinion Score(MoS)). 109 The metrics belong to the class of application level metrics defined 110 in [RFC6792]. 112 1.2. RTCP and RTCP XR Reports 114 The use of RTCP for reporting is defined in [RFC3550]. [RFC3611] 115 defined an extensible structure for reporting using an RTCP Extended 116 Report (XR). This document defines a new Extended Report block for 117 use with [RFC3550] and [RFC3611]. 119 1.3. Performance Metrics Framework 121 The Performance Metrics Framework [RFC6390] provides guidance on the 122 definition and specification of performance metrics. The RTP 123 Monitoring Architectures [RFC6792] provides guidelines for reporting 124 block format using RTCP XR. The XR block type described in this 125 document are in accordance with the guidelines in [RFC6390] and 126 [RFC6792]. 128 1.4. Applicability 130 The MoS Metrics Report Block can be used in any application of RTP 131 for which QoE measurement algorithms are defined. 133 The factors that affect real-time audio/video application quality can 134 be split into two categories. The first category consists of 135 transport-specific factors such as packet loss, delay and jitter 136 (which also translates into losses in the playback buffer). The 137 factors in the second category are application-specific factors that 138 affect real time application (e.g., video) quality. These factors 139 can be but are not limited to video codec and loss recovery 140 technique, coding bit rate, packetization scheme, and content 141 characteristics. 143 Compared with application-specific factors, the transport-specific 144 factors sometimes are not sufficient to measure real time media 145 quality, since the ability to analyze the real time media in the 146 application layer provides quantifiable measurements for end user 147 Quality of Experience (QoE) that may not be captured in the 148 transmission layers or from the RTP layer down. In a typical 149 scenario, monitoring of the transmission layers can produce 150 statistics suggesting that quality is not an issue, such as the fact 151 that network jitter is not excessive. However, problems may occur in 152 the service layers leading to poor subscriber QoE. Therefore 153 monitoring using only network-level measurements may be insufficient 154 when application layer media quality is required. 156 In order to provide accurate measures of real time media quality when 157 transporting real time media across a network, the QoE 158 Metrics(e.g.,MoS Metrics) are highly recommended which can be 159 conveyed in the RTCP XR packets [RFC3611] and may have the following 160 three benefits: 162 o Tuning the content encoder algorithm to satisfy real time data 163 quality requirements. 164 o Determining which system techniques to use in a given situation 165 and when to switch from one technique to another as system 166 parameters change. 167 o Verifying the continued correct operation of an existing system. 169 2. Terminology 171 2.1. Standards Language 173 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 174 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 175 document are to be interpreted as described in RFC 2119 [RFC2119]. 177 The terminology used is 179 Numeric formats S X:Y 181 where S indicates a two's complement signed representation, X 182 the number of bits prior to the decimal place and Y the number 183 of bits after the decimal place. 184 Hence 8:8 represents an unsigned number in the range 0.0 to 185 255.996 with a granularity of 0.0039. S7:8 would represent the 186 range -127.996 to +127.996. 0:16 represents a proper binary 187 fraction with range 188 0.0 to 1 - 1/65536 = 0.9999847 189 though note that use of flag values at the top of the numeric 190 range slightly reduces this upper limit. For example, if the 191 16- bit values 0xfffe and 0xffff are used as flags for "over- 192 range" and "unavailable" conditions, a 0:16 quantity has range 193 0.0 to 1 - 3/65536 = 0.9999542 195 3. MoS Metrics Block 197 Multimedia application MoS Metric is commonly expressed as a MOS 198 ("Mean Opinion Score"), MOS is on a scale from 1 to 5, in which 5 199 represents excellent and 1 represents unacceptable. MOS scores are 200 usually obtained using subjective testing or using objective 201 algorithm. However Subjective testing to estimate the multimedia 202 quality may be not suitable for measuring the multimedia quality 203 since the results may vary from test to test. Therefore using 204 objective algorithm to calculate MOS scores is RECOMMENDED. ITU-T 205 recommendations (e.g., [G.107][G.107.1][P.862][P.862.1][P.862.2] 207 [P.863][P.564][G.1082][P.1201.1][P.1201.2][P.1202.1][P.1202.2]) 208 define the methodologies for assessment of the performance of 209 multimedia stream and provides a method to evaluate QoE estimation 210 algorithms and objective model for video and audio. Hence this 211 document recommends vendors and implementers to use these 212 International Telecommunication Union (ITU)-specified methodologies 213 to measure parameters when possible. 215 This block reports the multimedia application performance or media 216 quality beyond the information carried in the standard RTCP packet 217 format. Information is recorded about MoS Metric which provides a 218 measure that gives a numerical indication of the perceived quality of 219 the media received. The measurement of metrics in this block are 220 usually made at the receiving end of the RTP stream. Instances of 221 this Metrics Block refer by Synchronization source (SSRC) to the 222 separate auxiliary Measurement Information block [RFC6776] which 223 describes measurement periods in use (see RFC6776 section 4.2). 225 This Metrics Block relies on the measurement period in the 226 Measurement Information block indicating the span of the report. 227 Senders MUST send this block in the same compound RTCP packet as the 228 measurement information block. Receivers MUST verify that the 229 measurement period is received in the same compound RTCP packet as 230 this Metrics Block. If not, this Metrics Block MUST be discarded. 232 3.1. Metric Block Structure 234 The report block contents are dependent upon a series of flag bits 235 carried in the first part of the header. Not all parameters need to 236 be reported in each block. Flags indicate which are and which are 237 not reported. The fields corresponding to unreported parameters MUST 238 be present, and MUST be set to zero. The receiver MUST ignore any 239 MoS Metrics Block with a non-zero value in any field flagged as 240 unreported. The encoding of MoS Metrics block payload consists of a 241 series of 32 bit units called segments that describe payload Type, 242 MoS algorithm and MoS value. 244 The MoS Metrics Block has the following format: 246 0 1 2 3 247 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 1 248 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 249 | BT=MMB | I | Reserved | Block Length | 250 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 251 | SSRC of source | 252 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 253 | Segment 1 | 254 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 255 | Segment 2 | 256 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 257 .................. 258 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 259 | Segment n | 260 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 262 3.2. Definition of Fields in MoS Metrics Block 264 Block type (BT): 8 bits 266 The MoS Metrics Block is identified by the constant . 268 Interval Metric flag (I): 2 bits 270 This field is used to indicate whether the MoS Metrics are 271 Sampled, Interval or Cumulative metrics [RFC6792]: 273 I=10: Interval Duration - the reported value applies to the 274 most recent measurement interval duration between successive 275 metrics reports. 276 I=11: Cumulative Duration - the reported value applies to the 277 accumulation period characteristic of cumulative measurements. 278 I=01: Sampled Value - the reported value is a sampled 279 instantaneous value. 281 In this document, the value I=00 is reserved for future use. 282 Senders MUST NOT use the values I=00. If a block is received with 283 I=00, the receiver MUST discard the block. 285 Reserved: 6 bits 287 This field is reserved for future definition. In the absence of 288 such a definition, the bits in this field MUST be set to zero and 289 ignored by the receiver (See RFC6709 section 4.2). 291 Block Length: 16 bits 293 The length of this report block in 32-bit words, minus one. For 294 the MoS Metrics Block, the block length is variable length. 296 SSRC of source: 32 bits 298 As defined in Section 4.1 of [RFC3611]. 300 Segment i: 32 bits 302 There are two segment types defined in this document: single 303 stream Audio/Video per SSRC segment, multi-channel audio per SSRC 304 segment. Multi-channel audio per SSRC segment is used to deal 305 with the case where Multi-channel audios are carried in one RTP 306 stream while single stream Audio/Video per SSRC segment is used to 307 deal with the case where each media stream is identified by SSRC 308 and sent in separate RTP stream. The leftmost bit of the segment 309 determines its type. If the leftmost bit of the segment is zero, 310 then it is single stream segment. If the leftmost bit is one, 311 then it is multi-channel audio segment. Note that two segment 312 types can not be present in the same metric block. 314 3.2.1. Single Stream audio/video per SSRC Segment 316 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 317 |S| CAID | PT | MOS Value | 318 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 320 Segment Type (S): 1 bit 322 This field is used to identify the segment type used in this 323 report block. A zero identifies this as a single stream Audio/ 324 Video per SSRC segment. Single stream means there is only one 325 media stream carried in one RTP stream. The single stream Audio/ 326 Video per SSRC segment can be used to report the MoS value 327 associated with the media stream identified by SSRC. If there are 328 multiple media streams and they want to use the single stream 329 Audio/Video per SSRC segment to report the MOS value, they should 330 be carried in the separate RTP streams with each identified by 331 different SSRC. In this case, multiple MoS Metrics Blocks are 332 required to report the MOS value corresponding to each media 333 stream using single stream Audio/Video per SSRC segment in the 334 same RTCP XR packet. 336 Calg Algorithm ID (CAID) : 8bits 338 The 8-bit CAID is the local identifier of calculation algorithm 339 associated with this segment in the range 1-255 inclusive. 341 Payload Type (PT): 7 bits 343 MoS Metrics reporting depends on the payload format in use. This 344 field identifies the format of the RTP payload. For RTP sessions 345 where multiple payload formats can be negotiated or the payload 346 format changes during the mid-session), the value of this field 347 will be used to indicate what payload format was in use for the 348 reporting interval. 350 MOS Value: 16 bits 352 The estimated mean opinion score for multimedia application 353 performance is defined as including the effects of delay,loss, 354 discard,jitter and other effects that would affect media quality. 355 It is expressed in numeric format 8:8 with the value in the range 356 0.0 to 255.996. The valid the measured value ranges from 0.0 to 357 50.0, corresponding to MoS x 10 as for MoS. If the measured value 358 is over ranged, the value 0xFFFE MUST be reported to indicate an 359 over-range measurement. If the measurement is unavailable, the 360 value 0xFFFF MUST be reported. Values other than 0xFFFE,0xFFFF 361 and the valid range defined above MUST NOT be sent and MUST be 362 ignored by the receiving system. 364 3.2.2. Multi-Channel audio per SSRC Segment 366 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 367 |S| CAID | PT |CHID | MOS Value | 368 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 370 Segment Type (S): 1 bit 372 This field is used to identify the segment type used in this 373 report block. A one identifies this as a multi-channel audio 374 segment. 376 CAlg Algorithm ID (CAID) : 8bits 378 The 8-bit ID is the local identifier of this segment in the range 379 1-255 inclusive. 381 Payload Type (PT): 7 bits 383 As defined in Section 3.2.1 of this document. 385 Channel Identifier (CHID): 3 bits 387 If multiple channels of audio are carried in one RTP stream, each 388 channel of audio will be viewed as a independent channel(e.g., 389 left channel audio, right channel audio). This field is used to 390 identify each channel carried in the same media stream. The 391 default Channel mapping follows static ordering rule described in 392 the section 4.1 of [RFC3551]. However there are some payload 393 formats that use different channel mappings, e.g., AC-3 audio over 394 RTP [RFC4184] only follow AC-3 channel order scheme defined in 395 [ATSC]. Enhanced AC-3 Audio over RTP [RFC4598] uses dynamic 396 channel transform mechanism. In order that the appropriate 397 channel mapping can be determined, MoS metrics reports need to be 398 tied to an RTP payload format, i.e., including the payload type of 399 the reported media according to [RFC6792] and using Payload Type 400 to determine the appropriate channel mapping. 402 MOS Value: 13 bits 404 The estimated mean opinion score for multimedia application 405 performance is defined as including the effects of delay,loss, 406 discard,jitter and other effects that would affect multimedia 407 quality . It is expressed in numeric format 6:7 with the value in 408 the range 0.0 to 63.992. The valid the measured value ranges from 409 0.0 to 50.0, corresponding to MoS x 10 as for MoS. If the 410 measured value is over ranged, the value 0x1FFE MUST be reported 411 to indicate an over-range measurement. If the measurement is 412 unavailable, the value 0x1FFF MUST be reported. Values other than 413 0x1FFE,0x1FFF and the valid range defined above MUST NOT be sent 414 and MUST be ignored by the receiving system. 416 4. SDP Signaling 418 [RFC3611] defines the use of SDP (Session Description Protocol) 419 [RFC4566] for signaling the use of XR blocks. However XR blocks MAY 420 be used without prior signaling (see section 5 of RFC3611). 422 4.1. SDP rtcp-xr-attrib Attribute Extension 424 This section augments the SDP [RFC4566] attribute "rtcp-xr" defined 425 in [RFC3611] by providing an additional value of "xr-format" to 426 signal the use of the report block defined in this document. Within 427 the "xr-format", the syntax element "calgextmap" is an attribute as 428 defined in [RFC4566] and used to signal the mapping of the local 429 identifier (CAID) in the segment extension defined in section 3.2 to 430 the calculation algorithm. Specific extensionattributes are defined 431 by the specification that defines a specific extension name; there 432 might be several. 434 xr-format =/ xr-mos-block 435 xr-mos-block = "mos-metrics" ["=" extmap *("," calgextmap)] 436 calgextmap = mapentry "=" extensionname [SP extentionattributes] 437 direction = "sendonly" / "recvonly" / "sendrecv" / "inactive" 438 mapentry = "calg:" 1*5 DIGIT ["/" direction] 439 extensionname = "P564";ITU-T P.564 Compliant Algorithm [P.564] 440 / "G107";ITU-T G.107 [G.107] 441 / "G107_1";ITU-T G.107.1 [G.107.1] 442 / "TS101_329";ETSI TS 101 329-5 Annex E [ ETSI] 443 /"JJ201_1 ";TTC JJ201.1 [TTC] 444 /"P1201_1";ITU-T P.1201.2 [P.1201.1] 445 /"P1201_2";ITU-T P.1201.2 [P.1201.2] 446 /"P1202_1";ITU-T P.1202.1 [P.1202.1] 447 /"P1202_2";ITU-T P.1202.2 [P.1202.2] 448 /"P.862.2";ITU-T P.862.2 [P.862.2] 449 /"P.863"; ITU-T P.863 [P.863] 450 / non-ws-string 451 extentionattributes = mosref 452 /attributes-ext 453 mosref = "mosref=" ("l"; lower resolution 454 /"m"; middle resolution 455 / "h";higher resolution 456 / non-ws-string) 457 mostype = "mostype=" ("e"; Estimated MoS [P.800.1] 458 /"s";subjective MoS [P.800.1] 459 /"o";objective MoS [P.800.1] 460 /non-ws-string) 461 attributes-ext = non-ws-string 462 SP = 463 non-ws-string = 1*(%x21-FF) 465 Each local identifier (CAID)of calculation algorithm used in the 466 segment defined in the section 3.2 is mapped to a string using an 467 attribute of the form: 469 a=calgextmap: ["/"] [] 470 where is a calculation algorithm name, as above, is 471 the local identifier (CAID)of the calculation algorithm associated 472 with the segment defined in this document and is an integer in the 473 valid range inclusive. 475 Example: 476 a=rtcp-xr:mos-metrics=calg:1=G107,calg:2=P1202_1 478 A usable mapping MUST use IDs in the valid range, and each ID in this 479 range MUST be unique and used only once for each stream or each 480 channel in the stream. 482 The mapping MUST be provided per media stream (in the media-level 483 section(s) of SDP, i.e., after an "m=" line). 485 The syntax element "mosref" is referred to the media resolution 486 relative reference (e.g., Narrowband (3.4kHz) Speech and Standard 487 Definition (SD) Resolution Video with lower resolution, Wideband 488 (7kHz) Speech and High Definition (HD) Resolution Video with higher 489 resolution). MOS scores reported in the mos metrics block might vary 490 with the MoS reference; For example, MOS values for narrowband, 491 wideband codecs occupy the same range but SHOULD be reported in 492 different value. For video application, MoS scores for SD 493 resolution, HD resolution video also occupy the same ranges and 494 SHOULD be reported in different value. 496 4.2. Offer/Answer Usage 498 When SDP is used in offer-answer context, the SDP Offer/Answer usage 499 defined in [RFC3611] applies. In the offer answer context, the 500 signaling described above might be used in three ways: 502 o asymmetric behavior (segment extensions sent in only one 503 direction), 504 o the offer of mutually exclusive alternatives, or 505 o the offer of more segments than can be sent in a single session. 507 A direction attribute MAY be included in a calgextmap; without it, 508 the direction implicitly inherits, of course, from the RTCP stream 509 direction. 511 Segment extension, with their directions, MAY be signaled for an 512 "inactive" stream. It is an error to use an extension direction 513 incompatible with the stream direction (e.g., a "sendonly" attribute 514 for a "recvonly" stream). 516 If an segment extension is offered as "sendrecv", explicitly or 517 implicitly, and asymmetric behavior is desired, the SDP MAY be 518 modified to modify or add direction qualifiers for that segment 519 extension. 521 A mosref attribute and mos type attribute MAY be included in an 522 calgextmap; without it, the mosref and most type attribute implicitly 523 inherits, of course, from the name attribute (e.g., P.1201.1 524 [P.1201.1] indicates lower resolution used while P.1201.2 [P.1201.2] 525 indicates higher resolution used) or payload type carried in the 526 segment extension (e.g.,EVRC-WB [RFC5188] indicates using Wideband 527 Codec). However not all payload types or MoS algorithm names 528 indicate resolution to be used and mos type to be used. 530 If an answerer receives an offer with an mosref attribute value it 531 doesn't support (e.g.,the answerer only supports "l" and receives 532 "h"from offerer), the answer SHOULD reject the mosref attribute value 533 offered by the offerer. 535 If the answerer wishes to reject a mosref attribute offered by the 536 offerer, it sets identifiers associated with segment extensions in 537 the answer to the value in the range 4096-4351. The rejected answer 538 MUST contain 'mosref ' attribute whose value is the value of the SDP 539 offer. 541 Local identifiers in the valid range inclusive in an offer or answer 542 must not be used more than once per media section. A session update 543 MAY change the direction qualifiers of segment extensions under use. 544 A session update MAY add or remove segment extension(s). Identifiers 545 values in the valid range MUST NOT be altered (remapped). 547 If a party wishes to offer mutually exclusive alternatives, then 548 multiple segment extensions with the same identifier in the 549 (unusable) range 4096-4351 MAY be offered; the answerer SHOULD select 550 at most one of the offered extensions with the same identifier, and 551 remap it to a free identifier in the valid range, for that extension 552 to be usable. Note that two segment types defined in section 3 are 553 also two exclusive alternatives. 555 If more segment extensions are offered in the valid range, the 556 answerer SHOULD choose those that are desired, and place the offered 557 identifier value "as is" in the SDP answer. 559 Similarly, if more segment extensions are offered than can be fit in 560 the valid range, identifiers in the range 4096-4351 MAY be offered; 561 the answerer SHOULD choose those that are desired, and remap them to 562 a free identifier in the valid range. 564 Note that the range 4096-4351 for these negotiation identifiers is 565 deliberately restricted to allow expansion of the range of valid 566 identifiers in future. Segment extensions with an identifier outside 567 the valid range cannot, of course, be used. 569 Example (port numbers, RTP profiles, payload IDs and rtpmaps, etc. 570 all omitted for brevity): 572 The offer: 574 a=rtcp-xr:mos- 575 metrics=calg:4906=P1201_l,calg:4906=P1202_l,calg:4907=G107 577 The answerer is interested in transmission P.1202.1 on lower 578 resolution application, but doesn't support P.1201.1 on lower 579 resolution application at all. It is interested in transmission 580 G.107. It therefore adjusts the declarations: 582 a=rtcp-xr:mos-metrics=calg:1=P1202_l,calg:2=G107 584 5. IANA Considerations 586 New block types for RTCP XR are subject to IANA registration. For 587 general guidelines on IANA considerations for RTCP XR, refer to 588 [RFC3611]. 590 5.1. New RTCP XR Block Type value 592 This document assigns the block type value MMB in the IANA " RTP 593 Control Protocol Extended Reports (RTCP XR) Block Type Registry" to 594 the "MoS Metrics Block". 596 [Note to RFC Editor: please replace MMB with the IANA provided RTCP 597 XR block type for this block.] 599 5.2. New RTCP XR SDP Parameter 601 This document also registers a new parameter "mos-metrics" in the " 602 RTP Control Protocol Extended Reports (RTCP XR) Session Description 603 Protocol (SDP) Parameters Registry". 605 5.3. The SDP calgextmap Attribute 607 This section contains the information required by [RFC4566] for an 608 SDP attribute. 609 o contact name, email address: 611 Qin Wu 612 sunseawq@huawei.com 614 o attribute name (as it will appear in SDP): calgextmap 615 o long-form attribute name in English: calculation algorithm map 616 definition 617 o type of attribute (session level, media level, or both): both 618 o whether the attribute value is subject to the charset attribute: 619 not subject to the charset attribute 620 o a one-paragraph explanation of the purpose of the attribute: This 621 attribute defines the mapping from the local identifier (CAID) in 622 the segment extension defined in section 3.2 into the calculation 623 algorithm name as documented in specifications and appropriately 624 registered. 625 o a specification of appropriate attribute values for this 626 attribute: see RFC xxxx. 628 5.4. New registry of calculation algorithms 630 This document creates a new registry to be called "RTCP XR MoS Metric 631 block - multimedia application Calculation Algorithm" as a sub- 632 registry of the "RTP Control Protocol Extended Reports (RTCP XR) 633 Block Type Registry". This registry applies to the multimedia 634 session where each type of media are sent in a separate RTP stream 635 and also applies to the session where Multi-channel audios are 636 carried in one RTP stream. Policies for this new registry are as 637 follows: 639 o The information required to support this assignment is an 640 unambiguous definition of the new metric, covering the base 641 measurements and how they are processed to generate the reported 642 metric. 644 o The review process for the registry is "Specification Required" as 645 described in Section 4.1 of [RFC5226]. 647 o Entries in the registry are identified by entry name and mapped to 648 the local identifier (CAID) in the segment extension defined in 649 section 3.2. 651 o Registration Template 653 The following information must be provided with each registration: 654 * Name: A string uniquely and unambiguously identifying the 655 Calculation algorithm for use in protocols. 656 * Name Description: A valid Description of the Calculation 657 algorithm name. 658 * Reference: The reference which defines the calculation 659 algorithm corresponding to the Name and Name Description. 661 * Type: The media type to which the calculation algorithm is 662 applied 664 o Initial assignments are as follows: 666 Name Name Description Reference Type 667 ========= =================================== ========== ==== 668 P564 ITU-T P.564 Compliant Algorithm [P.564] Voice 669 G107 ITU-T G.107 [G.107] Voice 670 TS101_329 ETSI TS 101 329-5 Annex E [ETSI] Voice 671 JJ201_1 TTC JJ201.1 [TTC] Voice 672 G107_1 ITU-T G.107.1 [G.107.1] Voice 673 P862 ITU-T P.862 [P.862] Voice 674 P862_2 ITU-T P.862.2 [P.862.2] Voice 675 P863 ITU-T P.863 [P.863] Voice 676 P1201_1 ITU-T P.1201.1 [P.1201.1] Multimedia 677 P1201_2 ITU-T P.1201.2 [P.1201.2] Multimedia 678 P1202_1 ITU-T P.1202.1 [P.1202.1] Video 679 P1202_2 ITU-T P.1202.2 [P.1202.2] Video 681 6. Security Considerations 683 The new RTCP XR report blocks proposed in this document introduces no 684 new security considerations beyond those described in [RFC3611]. 686 7. Authors 688 This draft merges ideas from two drafts addressing the MoS Metric 689 Reporting issue. The authors of these drafts are listed below (in 690 alphabetical order): 692 Alan Clark < alan.d.clark@telchemy.com > 693 Geoff Hunt < r.geoff.hunt@gmail.com > 694 Martin Kastner < martin.kastner@telchemy.com > 695 Kai Lee < leekai@ctbri.com.cn > 696 Roland Schott < roland.schott@telekom.de > 697 Qin Wu < sunseawq@huawei.com > 698 Glen Zorn < gwz@net-zen.net > 700 8. Acknowledgements 702 The authors gratefully acknowledge the comments and contributions 703 made by Bruce Adams, Philip Arden, Amit Arora, Bob Biskner, Kevin 704 Connor, Claus Dahm, Randy Ethier, Roni Even, Jim Frauenthal, Albert 705 Higashi, Tom Hock, Shane Holthaus, Paul Jones, Rajesh Kumar, Keith 706 Lantz, Mohamed Mostafa, Amy Pendleton, Colin Perkins, Mike Ramalho, 707 Ravi Raviraj, Albrecht Schwarz, Tom Taylor, Bill Ver Steeg, David R 708 Oran, Ali Begen and Hideaki Yamada. 710 9. References 712 9.1. Normative References 714 [ATSC] U.S. Advanced Television Systems Committee (ATSC), "ATSC 715 Standard: Digital Audio Compression (AC-3), Revision B", 716 ATSC Doc A/52B, June 2005. 718 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 719 Requirement Levels", BCP 14, RFC 2119, March 1997. 721 [RFC3550] Schulzrinne, H., "RTP: A Transport Protocol for Real-Time 722 Applications", RFC 3550, July 2003. 724 [RFC3551] Schulzrinne, H. and S. Casner, "RTP Profile for Audio and 725 Video Conferences with Minimal Control", RFC 3551, 726 July 2003. 728 [RFC3611] Friedman, T., Caceres, R., and A. Clark, "RTP Control 729 Protocol Extended Reports (RTCP XR)", RFC 3611, 730 November 2003. 732 [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session 733 Description Protocol", RFC 4566, July 2006. 735 [RFC5226] Narten, T., "Guidelines for Writing an IANA Considerations 736 Section in RFCs", RFC 5226, May 2008. 738 [RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax 739 Specifications: ABNF", STD 68, RFC 5234, January 2008. 741 [RFC6776] Wu, Q., "Measurement Identity and information Reporting 742 using SDES item and XR Block", RFC 6776, October 2012. 744 9.2. Informative References 746 [ETSI] ETSI, "Quality of Service (QoS) measurement 747 methodologies", ETSI TS 101 329-5 V1.1.1, November 2000. 749 [G.107] ITU-T, "The E Model, a computational model for use in 750 transmission planning", ITU-T Recommendation G.107, 751 April 2009. 753 [G.107.1] ITU-T, "Wideband E-model", ITU-T Recommendation G.107.1, 754 December 2011. 756 [G.1082] ITU-T, "Measurement-based methods for improving the 757 robustness of IPTV performance", ITU-T 758 Recommendation G.1082, April 2009. 760 [P.1201.1] 761 ITU-T, "Parametric non-intrusive assessment of audiovisual 762 media streaming quality - lower resolution application 763 area", ITU-T Recommendation P.1201.1, October 2012. 765 [P.1201.2] 766 ITU-T, "Parametric non-intrusive assessment of audiovisual 767 media streaming quality - higher resolution application 768 area", ITU-T Recommendation P.1201.2, October 2012. 770 [P.1202.1] 771 ITU-T, "Parametric non-intrusive bitstream assessment of 772 video media streaming quality - lower resolution 773 application area", ITU-T Recommendation P.1202.1, 774 October 2012. 776 [P.1202.2] 777 ITU-T, "Parametric non-intrusive bitstream assessment of 778 video media streaming quality - higher resolution 779 application area", ITU-T Recommendation P.1202.2, 780 May 2013. 782 [P.564] ITU-T, "Conformance testing for narrowband Voice over IP 783 transmission quality assessment models", ITU-T 784 Recommendation P.564, July 2006. 786 [P.862] ITU-T, "Perceptual evaluation of speech quality (PESQ): An 787 objective method for end-to-end speech quality assessment 788 of narrow-band telephone networks and speech codecs", 789 ITU-T Recommendation P.862, Febuary 2001. 791 [P.862.1] ITU-T, "Mapping function for transforming P.862 raw result 792 scores to MOS-LQO", ITU-T Recommendation P.862.1, 793 November 2003. 795 [P.862.2] ITU-T, "Wideband extension to Recommendation P.862 for the 796 assessment of wideband telephone networks and speech 797 codecs", ITU-T Recommendation P.862.2, November 2007. 799 [P.863] ITU-T, "Perceptual objective listening quality 800 assessment", ITU-T Recommendation P.863, January 2011. 802 [RFC4184] Link, B., Hager, T., and J. Flaks, "RTP Payload Format for 803 AC-3 Audio", RFC 4184, October 2005. 805 [RFC4598] Link, B., "Real-time Transport Protocol (RTP) Payload 806 Format for Enhanced AC-3 (E-AC-3) Audio", RFC 4598, 807 July 2006. 809 [RFC5188] Desineni, H. and Q. Xie, "RTP Payload Format for the 810 Enhanced Variable Rate Wideband Codec (EVRC-WB) and the 811 Media Subtype Updates for EVRC-B Codec", RFC 5188, 812 February 2008. 814 [RFC6390] Clark, A. and B. Claise, "Framework for Performance Metric 815 Development", RFC 6390, October 2011. 817 [RFC6792] Wu, Q., "Monitoring Architectures for RTP", RFC 6792, 818 November 2012. 820 [TTC] TTC 201.01 (Japan), "A method for speech quality 821 assessment for Voice over IP". 823 Appendix A. Example of User Quality of Experience Evaluation for video 824 stream 826 To evaluate user quality of experience levels using objective test 827 data, MoS Scores provide a familiar, easily understood numeric 828 representation of video, audio, and overall audiovisual quality. 829 Unlike audio, video is even more sensitive to transport impairments , 830 and even low rates of packet loss can cause severe degradation in 831 perceived quality. However, all occurrences of packet loss do not 832 have an equal impact on perceptual quality, in part because of the 833 way video frames are structured during the encoding process - such as 834 frame properties including frame type, frame structure and 835 quantization parameter (QP), and in part due to subjective factors - 836 such as the degree to which perception is affected by the levels of 837 motion, detail in the video sequence, and decoder characteristic 838 parameters including media resolution,codec type. When a video 839 stream is sent from the media source to RTP receiving end and get 840 monitored. in order to provide accurate evaluation of video quality, 841 one possible QoE evaluation method is having network nodes that 842 implement network management tools in place. They may know frame 843 properties,perception degree, decoder characteristic parameters of 844 this video stream using some out of band means, gather transport 845 impairment information received from the RTP receiving end and use 846 them as MoS calculation input parameters to calculate MoS scores by 847 choosing appropriate MoS calculation algorithm. Such MoS Scores 848 value can be useful for troubleshooting or comparing video quality 849 across different service types. 851 Appendix B. Metrics represented using RFC6390 Template 853 RFC EDITOR NOTE: please change XXXX in [RFCXXXX] by the new RFC 854 number, when assigned. 856 a. MoS Value Metric 858 * Metric Name: MoS 860 * Metric Description: The estimated mean opinion score for 861 multimedia application performance is defined as including the 862 effects of delay,loss, discard,jitter and other effects that 863 would affect multimedia quality. 865 * Method of Measurement or Calculation: See section 3.2.1, MoS 866 value definition [RFCXXXX]. 868 * Units of Measurement: See section 3.2.1, MoS value definition 869 [RFCXXXX]. 871 * Measurement Point(s) with Potential Measurement Domain: See 872 section 3, 2nd paragraph [RFCXXXX]. 874 * Measurement Timing: See section 3, 3rd paragraph [RFCXXXX] for 875 measurement timing and section 3.1 [RFCXXXX] for Interval 876 Metric flag. 878 * Use and applications: See section 1.4 [RFCXXXX]. 880 * Reporting model: See RFC3611. 882 b. Segment Type Metric 884 * Metric Name: Segment Type 886 * Metric Description: It is used to identify the segment type 887 used in this report block. For more details, see section 888 3.2.1, Segment type definition. 890 * Method of Measurement or Calculation: See section 3.2.1, 891 Segment Type definition [RFCXXXX]. 893 * Units of Measurement: See section 3.2.1, Segment Type 894 definition [RFCXXXX]. 896 * Measurement Point(s) with Potential Measurement Domain: See 897 section 3, 2nd paragraph [RFCXXXX]. 899 * Measurement Timing: See section 3, 3rd paragraph [RFCXXXX] for 900 measurement timing and section 3.1 [RFCXXXX] for Interval 901 Metric flag. 903 * Use and applications: See section 1.4 [RFCXXXX]. 905 * Reporting model: See RFC3611. 907 c. Calg Algorithm Identifier Metric 909 * Metric Name: Calg Algorithm Identifier 911 * Metric Description: It is the local identifier of calculation 912 Algorithm associated with this segment in the range 1-255 913 inclusive. 915 * Method of Measurement or Calculation: See section 3.2.1, Calg 916 Algorithm ID definition [RFCXXXX]. 918 * Units of Measurement: See section 3.2.1, Calg Algorithm ID 919 definition[RFCXXXX]. 921 * Measurement Point(s) with Potential Measurement Domain: See 922 section 3, 2nd paragraph [RFCXXXX]. 924 * Measurement Timing: See section 3, 3rd paragraph [RFCXXXX] for 925 measurement timing and section 3.1 [RFCXXXX] for Interval 926 Metric flag. 928 * Use and applications: See section 1.4 [RFCXXXX]. 930 * Reporting model: See RFC3611. 932 d. Payload Type Metric 934 * Metric Name: Payload Type 936 * Metric Description: It is used to identify the format of the 937 RTP payload. For more details, see section 3.2.1, payload 938 type definition. 940 * Method of Measurement or Calculation: See section 3.2.1, 941 Payload type definition [RFCXXXX]. 943 * Units of Measurement: See section 3.2.1, payload type 944 definition[RFCXXXX]. 946 * Measurement Point(s) with Potential Measurement Domain: See 947 section 3, 2nd paragraph [RFCXXXX]. 949 * Measurement Timing: See section 3, 3rd paragraph [RFCXXXX] for 950 measurement timing and section 3.1 [RFCXXXX] for Interval 951 Metric flag. 953 * Use and applications: See section 1.4 [RFCXXXX]. 955 * Reporting model: See RFC3611. 957 e. Channel Identifier Metric 959 * Metric Name: Payload Type 961 * Metric Description: It is used to identify each channel 962 carried in the same media stream. For more details, see 963 section 3.2.2, channel identifier definition. 965 * Method of Measurement or Calculation: See section 3.2.2, 966 Channel Identifier definition [RFCXXXX]. 968 * Units of Measurement: See section 3.2.2, channel identifier 969 definition[RFCXXXX]. 971 * Measurement Point(s) with Potential Measurement Domain: See 972 section 3, 2nd paragraph [RFCXXXX]. 974 * Measurement Timing: See section 3, 3rd paragraph [RFCXXXX] for 975 measurement timing and section 3.1 [RFCXXXX] for Interval 976 Metric flag. 978 * Use and applications: See section 1.4 [RFCXXXX]. 980 * Reporting model: See RFC3611. 982 Appendix C. Change Log 984 C.1. draft-ietf-xrblock-rtcp-xr-qoe-10 986 The following are the major changes compared to previous version: 988 o Replace QoE metrics with MoS metrics. 990 C.2. draft-ietf-xrblock-rtcp-xr-qoe-09 992 The following are the major changes compared to previous version: 993 o Address comments recieved from WGLC, PM-DIR Review and SDP review. 994 o Change an existing SDP attribute 'extmap' to new SDP attribute 995 'calgextmap' and add new SDP attribute registry. 996 o Add Reference to G.107.1, P.862.1, P.862.2 and P.863 for new 997 calculation algorithms. 998 o Add MoS type attribute to distinguish different MoS type. 999 o Other Editorial changes. 1001 C.3. draft-ietf-xrblock-rtcp-xr-qoe-08 1003 The following are the major changes compared to previous version: 1004 o Remove mostype attribute from SDP extension since it can inferred 1005 from payload type. 1006 o Clarify mosref attribute usage in the O/A. 1008 C.4. draft-ietf-xrblock-rtcp-xr-qoe-07 1010 The following are the major changes compared to previous version: 1011 o Some editorial changes to get in line with burst gap related 1012 draft. 1013 o Add an appendix to apply RFC6390 template. 1015 C.5. draft-ietf-xrblock-rtcp-xr-qoe-06 1017 The following are the major changes compared to previous two 1018 versions: 1019 o A few Contact information update. 1020 o A few Acknowledgement section update. 1022 C.6. draft-ietf-xrblock-rtcp-xr-qoe-04 1024 The following are the major changes compared to previous version: 1025 o Split two references P.NAMS and P.NBAMS into four references. 1026 o SDP signaling update. 1027 o Add one example to explain User QoE evaluation for video stream 1029 C.7. draft-ietf-xrblock-rtcp-xr-qoe-03 1031 The following are the major changes compared to previous version: 1032 o Add one new reference to support TTC JJ201.01. 1033 o Update two references P.NAMS and P.NBAMS. 1035 o Other Editorial changes based on comments applied to PDV and Delay 1036 drafts. 1038 C.8. draft-ietf-xrblock-rtcp-xr-qoe-02 1040 The following are the major changes compared to previous version: 1041 o Remove leftmost second bit since it is ueeless. 1042 o Change 13bits MoS value field into 14 bits to increase MoS 1043 precision. 1044 o Fix some typo and make some editorial changes. 1046 C.9. draft-ietf-xrblock-rtcp-xr-qoe-01 1048 The following are the major changes compared to previous version: 1049 o Remove layered support from the QoE Metric draft. 1050 o Allocate 7 bits in the block header for payload type to indicate 1051 what type of payload format is in use and add associated 1052 definition of payload type. 1053 o Clarify using Payload Type to determine the appropriate channel 1054 mapping in the definition of Channel Identifier. 1056 C.10. draft-ietf-xrblock-rtcp-xr-qoe-00 1058 The following are the major changes compared to previous version: 1059 o Allocate one more bit in the single stream per SSC segment to get 1060 alignment with the other two segment type. 1062 Authors' Addresses 1064 Alan Clark 1065 Telchemy Incorporated 1066 2905 Premiere Parkway, Suite 280 1067 Duluth, GA 30097 1068 USA 1070 Email: alan.d.clark@telchemy.com 1072 Qin Wu 1073 Huawei 1074 101 Software Avenue, Yuhua District 1075 Nanjing, Jiangsu 210012 1076 China 1078 Email: sunseawq@huawei.com 1079 Roland Schott 1080 Deutsche Telekom 1081 Heinrich-Hertz-Strasse 3-7 1082 Darmstadt 64295 1083 Germany 1085 Email: Roland.Schott@telekom.de 1087 Glen Zorn 1088 Network Zen 1089 77/440 Soi Phoomjit, Rama IV Road 1090 Phra Khanong, Khlong Toie 1091 Bangkok 10110 1092 Thailand 1094 Phone: +66 (0) 87 502 4274 1095 Email: gwz@net-zen.net