idnits 2.17.1 draft-ietf-xrblock-rtcp-xr-qoe-15.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 -- The document date (February 13, 2014) is 3725 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 956, but not defined == Unused Reference: 'RFC5234' is defined on line 741, but no explicit reference was found in the text == Unused Reference: 'G.1082' is defined on line 763, 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 (~~), 4 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: August 17, 2014 Huawei 6 R. Schott 7 Deutsche Telekom 8 G. Zorn 9 Network Zen 10 February 13, 2014 12 RTP Control Protocol (RTCP) Extended Report (XR) Blocks for MOS Metric 13 Reporting 14 draft-ietf-xrblock-rtcp-xr-qoe-15 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 mean opinion score (MOS) 21 Metrics for use in a range 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 August 17, 2014. 40 Copyright Notice 42 Copyright (c) 2014 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 . . . . . . . . . . . . . . . . . . . . . . 5 65 3.1. Metric Block Structure . . . . . . . . . . . . . . . . . . 6 66 3.2. Definition of Fields in MoS Metrics Block . . . . . . . . 7 67 3.2.1. Single Channel 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 . . . . . . . . . . . . . . . 15 76 5.4. New registry of calculation algorithms . . . . . . . . . . 15 77 6. Security Considerations . . . . . . . . . . . . . . . . . . . 16 78 7. Authors . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 79 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 17 80 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 17 81 9.1. Normative References . . . . . . . . . . . . . . . . . . . 17 82 9.2. Informative References . . . . . . . . . . . . . . . . . . 18 83 Appendix A. Metrics represented using RFC6390 Template . . . . . 19 84 Appendix B. Change Log . . . . . . . . . . . . . . . . . . . . . 22 85 B.1. draft-ietf-xrblock-rtcp-xr-qoe-15 . . . . . . . . . . . . 22 86 B.2. draft-ietf-xrblock-rtcp-xr-qoe-14 . . . . . . . . . . . . 22 87 B.3. draft-ietf-xrblock-rtcp-xr-qoe-10 . . . . . . . . . . . . 22 88 B.4. draft-ietf-xrblock-rtcp-xr-qoe-09 . . . . . . . . . . . . 23 89 B.5. draft-ietf-xrblock-rtcp-xr-qoe-08 . . . . . . . . . . . . 23 90 B.6. draft-ietf-xrblock-rtcp-xr-qoe-07 . . . . . . . . . . . . 23 91 B.7. draft-ietf-xrblock-rtcp-xr-qoe-06 . . . . . . . . . . . . 23 92 B.8. draft-ietf-xrblock-rtcp-xr-qoe-04 . . . . . . . . . . . . 23 93 B.9. draft-ietf-xrblock-rtcp-xr-qoe-03 . . . . . . . . . . . . 23 94 B.10. draft-ietf-xrblock-rtcp-xr-qoe-02 . . . . . . . . . . . . 24 95 B.11. draft-ietf-xrblock-rtcp-xr-qoe-01 . . . . . . . . . . . . 24 96 B.12. 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 (Quality of Experience) measurement algorithms are 132 defined. 134 The factors that affect real-time audio/video application quality can 135 be split into two categories. The first category consists of 136 transport-specific factors such as packet loss, delay and jitter 137 (which also translates into losses in the playback buffer). The 138 factors in the second category consists of content and codec related 139 factors such as codec type and loss recovery technique, coding bit 140 rate, packetization scheme, and content characteristics 142 Transport-specific factors may be insufficient to infer real time 143 media quality as codec related parameters and the interaction between 144 transport problems and application layer protocols can have a 145 substantial effect on observed media quality. Media quality may be 146 measured using algorithm that directly compare input and output media 147 streams, or may be estimated using algorithms that model the 148 interaction between media quality, protocol and encoded content. 149 Media quality is commonly expressed in terms of Mean Opinion Scores 150 (MOS) however is also represented by a range of indexes and other 151 scores. 153 The measurement of media quality has a number of applications: 154 o Detecting problems with media delivery or encoding that is 155 impacting user perceived quality. 156 o Tuning the content encoder algorithm to satisfy real time data 157 quality requirements. 158 o Determining which system techniques to use in a given situation 159 and when to switch from one technique to another as system 160 parameters change (for example as discussed in [P.1082]). 161 o Pre-qualifying a network to assess its ability to deliver an 162 acceptable end-user perceived quality level. 164 2. Terminology 166 2.1. Standards Language 168 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 169 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 170 document are to be interpreted as described in RFC 2119 [RFC2119]. 172 The terminology used is 174 Numeric formats X:Y 176 where X the number of bits prior to the decimal place and Y the 177 number of bits after the decimal place. 178 Hence 8:8 represents an unsigned number in the range 0.0 to 179 255.996 with a granularity of 0.0039. 0:16 represents a proper 180 binary fraction with range 181 0.0 to 1 - 1/65536 = 0.9999847 182 though note that use of flag values at the top of the numeric 183 range slightly reduces this upper limit. For example, if the 184 16- bit values 0xfffe and 0xffff are used as flags for "over- 185 range" and "unavailable" conditions, a 0:16 quantity has range 186 0.0 to 1 - 3/65536 = 0.9999542 188 3. MoS Metrics Block 190 Multimedia application MOS Metric is commonly expressed as a MOS 191 ("Mean Opinion Score"), MOS is usually on a scale from 1 to 5, in 192 which 5 represents excellent and 1 represents unacceptable however 193 can use other ranges (for example 1 to 11). The term "MOS score" 194 originates from subjective testing, and is used to refer to the Mean 195 of a number of individual Opinion Scores. There is therefore a well 196 understood relationship between MOS and user experience, hence the 197 industry commonly uses MOS as the scale for objective test results. 198 Subjective tests can be used for measuring live network traffic 199 however the use of objective or algorithmic measurement techniques 200 allows much larger scale measurements to be made. Within the scope 201 of this document, MOS scores are obtained using objective or 202 estimation algorithms. ITU-T or ITU-R recommendations (e.g., 203 [BS.1387-1][G.107][G.107.1][P.862][P.862.1][P.862.2][P.863][P.564][G. 204 1082][P.1201.1][P.1201.2][P.1202.1][P.1202.2]) define methodologies 205 for assessment of the performance of audio and video streams. Other 206 international and national standards organizations such as EBU, ETSI, 207 IEC and IEEE also define QoE algorithms and methodologies, and the 208 intent of this document is not to restrict its use to ITU 209 recommendations but to suggest that ITU recommendations be used where 210 they are defined. 212 This block reports media quality in the form of a 1-5 MOS range 213 however does not report QoE scores that include parameters outside 214 the scope of the RTP stream, for example signaling performance, MTTR 215 or other factors that may affect the overall user experience. 217 The MOS Metric reported in this block gives a numerical indication of 218 the perceived quality of the received media stream, which is 219 typically measured at the receiving end of the RTP stream. Instances 220 of this Metrics Block refer by Synchronization source (SSRC) to the 221 separate auxiliary Measurement Information block [RFC6776] which 222 describes measurement periods in use (see RFC6776 section 4.2). 224 This Metrics Block relies on the measurement period in the 225 Measurement Information block indicating the span of the report. 226 Senders MUST send this block in the same compound RTCP packet as the 227 measurement information block. Receivers MUST verify that the 228 measurement period is received in the same compound RTCP packet as 229 this Metrics Block. If not, this Metrics Block MUST be discarded. 231 3.1. Metric Block Structure 233 The MOS Metrics Block has the following format: 235 0 1 2 3 236 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 1 237 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 238 | BT=MMB | I | Reserved | Block Length | 239 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 240 | SSRC of source | 241 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 242 | Segment 1 | 243 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 244 | Segment 2 | 245 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 246 .................. 247 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 248 | Segment n | 249 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 251 3.2. Definition of Fields in MoS Metrics Block 253 Block type (BT): 8 bits 255 The MOS Metrics Block is identified by the constant . 257 Interval Metric flag (I): 2 bits 259 This field is used to indicate whether the MOS Metrics are 260 Sampled, Interval or Cumulative [RFC6792]: 262 I=10: Interval Duration - the reported value applies to the 263 most recent measurement interval duration between successive 264 metrics reports. 265 I=11: Cumulative Duration - the reported value applies to the 266 accumulation period characteristic of cumulative measurements. 267 I=01: Sampled Value - the reported value is a sampled 268 instantaneous value. 269 I=00: Reserved 271 In this document, MOS Metrics MAY be reported for intervals or for 272 the duration of the media stream (cumulative). The value I=01, 273 indicating a sampled value, MUST NOT be sent, and MUST be 274 discarded when received. 276 Reserved: 6 bits 278 This field is reserved for future definition. In the absence of 279 such a definition, the bits in this field MUST be set to zero and 280 ignored by the receiver (See RFC6709 section 4.2). 282 Block Length: 16 bits 284 The length of this report block in 32-bit words, minus one. For 285 the MOS Metrics Block, the block length is variable length. 287 SSRC of source: 32 bits 289 As defined in Section 4.1 of [RFC3611]. 291 Segment i: 32 bits 293 There are two segment types defined in this document: single 294 stream Audio/Video per SSRC segment, multi-channel audio per SSRC 295 segment. Multi-channel audio per SSRC segment is used to deal 296 with the case where Multi-channel audios are carried in one RTP 297 stream while single channel Audio/Video per SSRC segment is used 298 to deal with the case where each media stream is identified by 299 SSRC and sent in separate RTP stream. The leftmost bit of the 300 segment determines its type. If the leftmost bit of the segment 301 is zero, then it is single channel segment. If the leftmost bit 302 is one, then it is multi-channel audio segment. Note that two 303 segment types can not be present in the same metric block. 305 3.2.1. Single Channel audio/video per SSRC Segment 307 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 308 |S| CAID | PT | MOS Value | 309 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 311 Segment Type (S): 1 bit 313 This field is used to identify the segment type used in this 314 report block. A zero identifies this as a single channel Audio/ 315 Video per SSRC segment. Single channel means there is only one 316 media stream carried in one RTP stream. The single channel Audio/ 317 Video per SSRC segment can be used to report the MOS value 318 associated with the media stream identified by SSRC. If there are 319 multiple media streams and they want to use the single channel 320 Audio/Video per SSRC segment to report the MOS value, they should 321 be carried in the separate RTP streams with each identified by 322 different SSRC. In this case, multiple MOS Metrics Blocks are 323 required to report the MOS value corresponding to each media 324 stream using single channel Audio/Video per SSRC segment in the 325 same RTCP XR packet. 327 Calculation Algorithm ID (CAID) : 8 bits 329 The 8-bit CAID is the session specific reference to the 330 calculation algorithm and associated qualifiers indicated in SDP 331 (see Section 4.1) and used to compute QoE scores for this segment. 333 Payload Type (PT): 7 bits 335 MOS Metrics reporting depends on the payload format in use. This 336 field identifies the RTP payload type in use during the reporting 337 interval. The binding between RTP payload types and RTP payload 338 formats is configured via a signalling protocol, for example an 339 SDP offer/answer exchange. If the RTP payload type used is 340 changed during an RTP session, separate reports SHOULD be sent for 341 each RTP payload type, with corresponding measurement information 342 blocks indicating the time period to which they relate. 344 Note that the use of this Report Block with MPEG Transport streams 345 carried over RTP is undefined as each MPEG Transport stream may 346 use distinct audio or video codecs and the indication of the 347 encoding of these is within the MPEG Transport stream and does not 348 use RTP payloads. 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 A 1-5 MOS score is multiplied by 10 and then represented in the 356 7:9 format. A value of 0xFFFE is a flag indicating that the 357 measured value is out of range. A value of 0xFFFF is a flag 358 indicating that the measurement is unavailable. Values other than 359 0xFFFE, 0xFFFF and the valid range defined above MUST NOT be sent 360 and MUST be ignored by the receiving system. 362 3.2.2. Multi-Channel audio per SSRC Segment 364 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 365 |S| CAID | PT |CHID | MOS Value | 366 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 368 Segment Type (S): 1 bit 370 This field is used to identify the segment type used in this 371 report block. A one identifies this as a multi-channel audio 372 segment. 374 Calculation Algorithm ID (CAID) : 8 bits 376 The 8-bit CAID is the session specific reference to the 377 calculation algorithm and associated qualifiers indicated in SDP 378 (see Section 4.1) and used to compute QoE scores for this segment. 380 Payload Type (PT): 7 bits 382 As defined in Section 3.2.1 of this document 384 Channel Identifier (CHID): 3 bits 386 If multiple channels of audio are carried in one RTP stream, each 387 channel of audio will be viewed as a independent channel(e.g., 388 left channel audio, right channel audio). This field is used to 389 identify each channel carried in the same media stream. The 390 default Channel mapping follows static ordering rule described in 391 the section 4.1 of [RFC3551]. However there are some payload 392 formats that use different channel mappings, e.g., AC-3 audio over 393 RTP [RFC4184] only follow AC-3 channel order scheme defined in 394 [ATSC]. Enhanced AC-3 Audio over RTP [RFC4598] uses dynamic 395 channel transform mechanism. In order that the appropriate 396 channel mapping can be determined, MOS metrics reports need to be 397 tied to an RTP payload format, i.e., including the payload type of 398 the reported media according to [RFC6792] and using Payload Type 399 to determine the appropriate channel mapping. 401 MOS Value: 13 bits 403 The estimated Mean Opinion Score for multimedia application 404 performance includes the effects of delay,loss, discard, jitter 405 and other effects that would affect multimedia quality. The 406 estimated MOS value is multiplied by 10 and expressed in 7:6 407 format. A value of 0x1FFE is a flag indicating that the measured 408 value is out of range. A value of 0x1FFF is a flag indicating 409 that the measurement is unavailable. Values other than 0x1FFE, 410 0x1FFF and the valid range defined above MUST NOT be sent and MUST 411 be ignored by the receiving system. 413 4. SDP Signaling 415 [RFC3611]defines the use of SDP (Session Description Protocol) 416 [RFC4566] for signaling the use of XR blocks. However XR blocks MAY 417 be used without prior signaling (see section 5 of RFC3611). 419 4.1. SDP rtcp-xr-attrib Attribute Extension 421 This section augments the SDP [RFC4566] attribute "rtcp-xr" defined 422 in [RFC3611] by providing an additional value of "xr-format" to 423 signal the use of the report block defined in this document. Within 424 the "xr-format", the syntax element "calgextmap" is an attribute as 425 defined in [RFC4566] and used to signal the mapping of the local 426 identifier (CAID) in the segment extension defined in section 3.2 to 427 the calculation algorithm. Specific extensionattributes are defined 428 by the specification that defines a specific extension name; there 429 might be several. 431 xr-format =/ xr-mos-block 432 xr-mos-block = "mos-metrics" ["=" calgextmap *("," calgextmap)] 433 calgextmap = mapentry "=" extensionname [SP extentionattributes] 434 direction = "sendonly" / "recvonly" / "sendrecv" / "inactive" 435 mapentry = "calg:" 1*3 DIGIT ["/" direction] 436 ; Values in the range 1-255 are valid 437 ; if needed, 0 can be used to indicate that 438 ; an algorithm is rejected 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 extensionattributes = mosref 452 /attributes-ext 453 mosref = "mosref=" ("l"; lower resolution 454 /"m"; middle resolution 455 / "h";higher resolution 456 / non-ws-string) 457 attributes-ext = non-ws-string 458 SP = 459 non-ws-string = 1*(%x21-FF) 461 Each local identifier (CAID)of calculation algorithm used in the 462 segment defined in the section 3.2 is mapped to a string using an 463 attribute of the form: 465 a=calg: ["/"] [] 466 where is a calculation algorithm name, as above, is 467 the local identifier (CAID)of the calculation algorithm associated 468 with the segment defined in this document and is an integer in the 469 valid range inclusive. 471 Example: 472 a=rtcp-xr:mos-metrics=calg:1=G107,calg:2=P1202_1 474 A usable mapping MUST use IDs in the valid range, and each ID in this 475 range MUST be unique and used only once for each stream or each 476 channel in the stream. 478 The mapping MUST be provided per media stream (in the media-level 479 section(s) of SDP, i.e., after an "m=" line). 481 The syntax element "mosref" is referred to the media resolution 482 relative reference and has three valules 'l','m','h'.(e.g., 483 Narrowband (3.4kHz) Speech and Standard Definition (SD) or lower 484 Resolution Video have 'l' resolution, Super Wideband (>14kHz) Speech 485 or higher and High Definition (HD) or higher Resolution Video have 486 'h' Resolution, Wideband speech(7khz) and Video with resolution 487 between SD and HD has 'm' resolution). MOS scores reported in the 488 mos metrics block might vary with the MOS reference; For example, MOS 489 values for narrowband, wideband, super wideband codecs occupy the 490 same range but SHOULD be reported in different value. For video 491 application, MOS scores for SD resolution, HD resolution video also 492 occupy the same ranges and SHOULD be reported in different value. 494 4.2. Offer/Answer Usage 496 When SDP is used in offer-answer context, the SDP Offer/Answer usage 497 defined in [RFC3611] applies. In the offer answer context, the 498 signaling described above might be used in three ways: 500 o asymmetric behavior (segment extensions sent in only one 501 direction), 502 o the offer of mutually exclusive alternatives, or 503 o the offer of more segments than can be sent in a single session. 505 A direction attribute MAY be included in a calgextmap; without it, 506 the direction implicitly inherits, of course, from the RTCP stream 507 direction. 509 Segment extensions, with their directions, MAY be signaled for an 510 "inactive" stream. An extension direction MUST be compatible with 511 the stream direction. If a segment extension in the SDP offer is 512 marked as "sendonly" and the answerer desires to receive it, the 513 extension MUST be marked as "recvonly" in the SDP answer. An 514 answerer that has no desire to receive the extension or does not 515 understand the extension SHOULD NOT include it from the SDP answer. 517 If a segment extension is marked as "recvonly" in the SDP offer and 518 the answerer desires to send it, the extension MUST be marked as 519 "sendonly" in the SDP answer. An answerer that has no desire to, or 520 is unable to, send the extension SHOULD NOT include it from the SDP 521 answer. 523 If a segment extension is offered as "sendrecv", explicitly or 524 implicitly, and asymmetric behavior is desired, the SDP MAY be 525 modified to modify or add direction qualifiers for that segment 526 extension. 528 A mosref attribute and mos type attribute MAY be included in an 529 calgextmap; without it, the mosref and most type attribute implicitly 530 inherits, of course, from the name attribute (e.g., P.1201.1 531 [P.1201.1] indicates lower resolution used while P.1201.2 [P.1201.2] 532 indicates higher resolution used) or payload type carried in the 533 segment extension (e.g.,EVRC-WB [RFC5188] indicates using Wideband 534 Codec). However not all payload types or MOS algorithm names 535 indicate resolution to be used and mos type to be used. If an 536 answerer receives an offer with an mosref attribute value it doesn't 537 support (e.g.,the answerer only supports "l" and receives "h"from 538 offerer), the answer SHOULD reject the mosref attribute value offered 539 by the offerer. 541 If the answerer wishes to reject a mosref attribute offered by the 542 offerer, it sets identifiers associated with segment extensions in 543 the answer to the value in the range 4096-4351. The rejected answer 544 MUST contain 'mosref ' attribute whose value is the value of the SDP 545 offer. 547 Local identifiers in the valid range inclusive in an offer or answer 548 must not be used more than once per media section. A session update 549 MAY change the direction qualifiers of segment extensions under use. 550 A session update MAY add or remove segment extension(s). Identifiers 551 values in the valid range MUST NOT be altered (remapped). 553 If a party wishes to offer mutually exclusive alternatives, then 554 multiple segment extensions with the same identifier in the 555 (unusable) range 4096-4351 MAY be offered; the answerer SHOULD select 556 at most one of the offered extensions with the same identifier, and 557 remap it to a free identifier in the valid range, for that extension 558 to be usable. Note that two segment types defined in section 3 are 559 also two exclusive alternatives. 561 If more segment extensions are offered in the valid range, the 562 answerer SHOULD choose those that are desired, and place the offered 563 identifier value "as is" in the SDP answer. 565 Similarly, if more segment extensions are offered than can be fit in 566 the valid range, identifiers in the range 4096-4351 MAY be offered; 567 the answerer SHOULD choose those that are desired, and remap them to 568 a free identifier in the valid range. 570 Note that the range 4096-4351 for these negotiation identifiers is 571 deliberately restricted to allow expansion of the range of valid 572 identifiers in future. Segment extensions with an identifier outside 573 the valid range cannot, of course, be used. 575 Example (port numbers, RTP profiles, payload IDs and rtpmaps, etc. 576 all omitted for brevity): 578 The offer: 580 a=rtcp-xr:mos-metrics=calg:4906=P1201_l,calg:4906=P1202_l, calg: 581 4907=G107 583 The answerer is interested in transmission P.1202.1 on lower 584 resolution application, but doesn't support P.1201.1 on lower 585 resolution application at all. It is interested in transmission 586 G.107. It therefore adjusts the declarations: 588 a=rtcp-xr:mos-metrics=calg:1=P1202_l,calg:2=G107 590 5. IANA Considerations 592 New block types for RTCP XR are subject to IANA registration. For 593 general guidelines on IANA considerations for RTCP XR, refer to 594 [RFC3611]. 596 5.1. New RTCP XR Block Type value 598 This document assigns the block type value MMB in the IANA " RTP 599 Control Protocol Extended Reports (RTCP XR) Block Type Registry" to 600 the "MOS Metrics Block". 602 [Note to RFC Editor: please replace MMB with the IANA provided RTCP 603 XR block type for this block.] 605 5.2. New RTCP XR SDP Parameter 607 This document also registers a new parameter "mos-metrics" in the " 608 RTP Control Protocol Extended Reports (RTCP XR) Session Description 609 Protocol (SDP) Parameters Registry". 611 5.3. The SDP calgextmap Attribute 613 This section contains the information required by [RFC4566] for an 614 SDP attribute. 615 o contact name, email address: ietf 616 o attribute name (as it will appear in SDP): calgextmap 617 o long-form attribute name in English: calculation algorithm map 618 definition 619 o type of attribute (session level, media level, or both): both 620 o whether the attribute value is subject to the charset attribute: 621 not subject to the charset attribute 622 o a one-paragraph explanation of the purpose of the attribute: This 623 attribute defines the mapping from the local identifier (CAID) in 624 the segment extension defined in section 3.2 into the calculation 625 algorithm name as documented in specifications and appropriately 626 registered. 627 o a specification of appropriate attribute values for this 628 attribute: see RFC xxxx. 630 5.4. New registry of calculation algorithms 632 This document creates a new registry to be called "RTCP XR MOS Metric 633 block - multimedia application Calculation Algorithm" as a sub- 634 registry of the "RTP Control Protocol Extended Reports (RTCP XR) 635 Block Type Registry". This registry applies to the multimedia 636 session where each type of media are sent in a separate RTP stream 637 and also applies to the session where Multi-channel audios are 638 carried in one RTP stream. Policies for this new registry are as 639 follows: 641 o The information required to support this assignment is an 642 unambiguous definition of the new metric, covering the base 643 measurements and how they are processed to generate the reported 644 metric. 646 o The review process for the registry is "Specification Required" as 647 described in Section 4.1 of [RFC5226]. 649 o Entries in the registry are identified by entry name and mapped to 650 the local identifier (CAID) in the segment extension defined in 651 section 3.2. 653 o Registration Template 655 The following information must be provided with each registration: 657 * Name: A string uniquely and unambiguously identifying the 658 Calculation algorithm for use in protocols. 659 * Name Description: A valid Description of the Calculation 660 algorithm name. 661 * Reference: The reference which defines the calculation 662 algorithm corresponding to the Name and Name Description. 663 * Type: The media type to which the calculation algorithm is 664 applied 666 o Initial assignments are as follows: 668 Name Name Description Reference Type 669 ========= =================================== ========== ==== 670 P564 ITU-T P.564 Compliant Algorithm [P.564] Voice 671 G107 ITU-T G.107 [G.107] Voice 672 TS101_329 ETSI TS 101 329-5 Annex E [ETSI] Voice 673 JJ201_1 TTC JJ201.1 [TTC] Voice 674 G107_1 ITU-T G.107.1 [G.107.1] Voice 675 P862 ITU-T P.862 [P.862] Voice 676 P862_2 ITU-T P.862.2 [P.862.2] Voice 677 P863 ITU-T P.863 [P.863] Voice 678 P1201_1 ITU-T P.1201.1 [P.1201.1] Multimedia 679 P1201_2 ITU-T P.1201.2 [P.1201.2] Multimedia 680 P1202_1 ITU-T P.1202.1 [P.1202.1] Video 681 P1202_2 ITU-T P.1202.2 [P.1202.2] Video 683 6. Security Considerations 685 The new RTCP XR report blocks proposed in this document introduces no 686 new security considerations beyond those described in [RFC3611]. 688 7. Authors 690 This draft merges ideas from two drafts addressing the MOS Metric 691 Reporting issue. The authors of these drafts are listed below (in 692 alphabetical order): 694 Alan Clark < alan.d.clark@telchemy.com > 695 Geoff Hunt < r.geoff.hunt@gmail.com > 696 Martin Kastner < martin.kastner@telchemy.com > 697 Qin Wu < sunseawq@huawei.com > 698 Roland Schott < roland.schott@telekom.de > 699 Glen Zorn < gwz@net-zen.net > 700 Kai Lee < leekai@ctbri.com.cn > 702 8. Acknowledgements 704 The authors gratefully acknowledge the comments and contributions 705 made by Bruce Adams, Philip Arden, Amit Arora, Bob Biskner, Kevin 706 Connor, Claus Dahm, Randy Ethier, Roni Even, Jim Frauenthal, Albert 707 Higashi, Tom Hock, Shane Holthaus, Paul Jones, Rajesh Kumar, Keith 708 Lantz, Mohamed Mostafa, Amy Pendleton, Colin Perkins, Mike Ramalho, 709 Ravi Raviraj, Albrecht Schwarz, Tom Taylor, Bill Ver Steeg, David R 710 Oran, Ted Lemon,Benoit Claise, Pete Resnick, Ali Begen and Hideaki 711 Yamada. 713 9. References 715 9.1. Normative References 717 [ATSC] U.S. Advanced Television Systems Committee (ATSC), "ATSC 718 Standard: Digital Audio Compression (AC-3), Revision B", 719 ATSC Doc A/52B, June 2005. 721 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 722 Requirement Levels", BCP 14, RFC 2119, March 1997. 724 [RFC3550] Schulzrinne, H., "RTP: A Transport Protocol for Real-Time 725 Applications", RFC 3550, July 2003. 727 [RFC3551] Schulzrinne, H. and S. Casner, "RTP Profile for Audio and 728 Video Conferences with Minimal Control", RFC 3551, 729 July 2003. 731 [RFC3611] Friedman, T., Caceres, R., and A. Clark, "RTP Control 732 Protocol Extended Reports (RTCP XR)", RFC 3611, 733 November 2003. 735 [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session 736 Description Protocol", RFC 4566, July 2006. 738 [RFC5226] Narten, T., "Guidelines for Writing an IANA Considerations 739 Section in RFCs", RFC 5226, May 2008. 741 [RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax 742 Specifications: ABNF", STD 68, RFC 5234, January 2008. 744 [RFC6776] Wu, Q., "Measurement Identity and information Reporting 745 using SDES item and XR Block", RFC 6776, October 2012. 747 9.2. Informative References 749 [BS.1387-1] 750 ITU-R, "Method for objective measurements of perceived 751 audio quality", ITU-R Recommendation BS.1387-1, 2001. 753 [ETSI] ETSI, "Quality of Service (QoS) measurement 754 methodologies", ETSI TS 101 329-5 V1.1.1, November 2000. 756 [G.107] ITU-T, "The E Model, a computational model for use in 757 transmission planning", ITU-T Recommendation G.107, 758 April 2009. 760 [G.107.1] ITU-T, "Wideband E-model", ITU-T Recommendation G.107.1, 761 December 2011. 763 [G.1082] ITU-T, "Measurement-based methods for improving the 764 robustness of IPTV performance", ITU-T 765 Recommendation G.1082, April 2009. 767 [P.1201.1] 768 ITU-T, "Parametric non-intrusive assessment of audiovisual 769 media streaming quality - lower resolution application 770 area", ITU-T Recommendation P.1201.1, October 2012. 772 [P.1201.2] 773 ITU-T, "Parametric non-intrusive assessment of audiovisual 774 media streaming quality - higher resolution application 775 area", ITU-T Recommendation P.1201.2, October 2012. 777 [P.1202.1] 778 ITU-T, "Parametric non-intrusive bitstream assessment of 779 video media streaming quality - lower resolution 780 application area", ITU-T Recommendation P.1202.1, 781 October 2012. 783 [P.1202.2] 784 ITU-T, "Parametric non-intrusive bitstream assessment of 785 video media streaming quality - higher resolution 786 application area", ITU-T Recommendation P.1202.2, 787 May 2013. 789 [P.564] ITU-T, "Conformance testing for narrowband Voice over IP 790 transmission quality assessment models", ITU-T 791 Recommendation P.564, July 2006. 793 [P.862] ITU-T, "Perceptual evaluation of speech quality (PESQ): An 794 objective method for end-to-end speech quality assessment 795 of narrow-band telephone networks and speech codecs", 796 ITU-T Recommendation P.862, Febuary 2001. 798 [P.862.1] ITU-T, "Mapping function for transforming P.862 raw result 799 scores to MOS-LQO", ITU-T Recommendation P.862.1, 800 November 2003. 802 [P.862.2] ITU-T, "Wideband extension to Recommendation P.862 for the 803 assessment of wideband telephone networks and speech 804 codecs", ITU-T Recommendation P.862.2, November 2007. 806 [P.863] ITU-T, "Perceptual objective listening quality 807 assessment", ITU-T Recommendation P.863, January 2011. 809 [RFC4184] Link, B., Hager, T., and J. Flaks, "RTP Payload Format for 810 AC-3 Audio", RFC 4184, October 2005. 812 [RFC4598] Link, B., "Real-time Transport Protocol (RTP) Payload 813 Format for Enhanced AC-3 (E-AC-3) Audio", RFC 4598, 814 July 2006. 816 [RFC5188] Desineni, H. and Q. Xie, "RTP Payload Format for the 817 Enhanced Variable Rate Wideband Codec (EVRC-WB) and the 818 Media Subtype Updates for EVRC-B Codec", RFC 5188, 819 February 2008. 821 [RFC6390] Clark, A. and B. Claise, "Framework for Performance Metric 822 Development", RFC 6390, October 2011. 824 [RFC6792] Wu, Q., "Monitoring Architectures for RTP", RFC 6792, 825 November 2012. 827 [TTC] TTC 201.01 (Japan), "A method for speech quality 828 assessment for Voice over IP". 830 Appendix A. Metrics represented using RFC6390 Template 832 RFC EDITOR NOTE: please change XXXX in [RFCXXXX] by the new RFC 833 number, when assigned. 835 a. MOS Value Metric 837 * Metric Name: MOS in RTP 839 * Metric Description: The estimated Mean Opinion Score for 840 multimedia application performance of RTP stream is defined as 841 including the effects of delay,loss, discard,jitter and other 842 effects that would affect audio or video quality. 844 * Method of Measurement or Calculation: See section 3.2.1, MOS 845 value definition [RFCXXXX]. 847 * Units of Measurement: See section 3.2.1, MOS value definition 848 [RFCXXXX]. 850 * Measurement Point(s) with Potential Measurement Domain: See 851 section 3, 2nd paragraph [RFCXXXX]. 853 * Measurement Timing: See section 3, 3rd paragraph [RFCXXXX] for 854 measurement timing and section 3.1 [RFCXXXX] for Interval 855 Metric flag. 857 * Use and applications: See section 1.4 [RFCXXXX]. 859 * Reporting model: See RFC3611. 861 b. Segment Type Metric 863 * Metric Name: Segment Type in RTP 865 * Metric Description: It is used to identify the segment type of 866 RTP stream used in this report block. For more details, see 867 section 3.2.1, Segment type definition. 869 * Method of Measurement or Calculation: See section 3.2.1, 870 Segment Type definition [RFCXXXX]. 872 * Units of Measurement: See section 3.2.1, Segment Type 873 definition [RFCXXXX]. 875 * Measurement Point(s) with Potential Measurement Domain: See 876 section 3, 2nd paragraph [RFCXXXX]. 878 * Measurement Timing: See section 3, 3rd paragraph [RFCXXXX] for 879 measurement timing and section 3.1 [RFCXXXX] for Interval 880 Metric flag. 882 * Use and applications: See section 1.4 [RFCXXXX]. 884 * Reporting model: See RFC3611. 886 c. Calculation Algorithm Identifier Metric 887 * Metric Name: RTP Stream Calculation Algorithm Identifier 889 * Metric Description: It is the local identifier of RTP Stream 890 calculation Algorithm associated with this segment in the 891 range 1-255 inclusive. 893 * Method of Measurement or Calculation: See section 3.2.1, 894 Calculation Algorithm ID definition [RFCXXXX]. 896 * Units of Measurement: See section 3.2.1, Calg Algorithm ID 897 definition[RFCXXXX]. 899 * Measurement Point(s) with Potential Measurement Domain: See 900 section 3, 2nd paragraph [RFCXXXX]. 902 * Measurement Timing: See section 3, 3rd paragraph [RFCXXXX] for 903 measurement timing and section 3.1 [RFCXXXX] for Interval 904 Metric flag. 906 * Use and applications: See section 1.4 [RFCXXXX]. 908 * Reporting model: See RFC3611. 910 d. Payload Type Metric 912 * Metric Name: RTP Payload Type 914 * Metric Description: It is used to identify the format of the 915 RTP payload. For more details, see section 3.2.1, payload 916 type definition. 918 * Method of Measurement or Calculation: See section 3.2.1, 919 Payload type definition [RFCXXXX]. 921 * Units of Measurement: See section 3.2.1, payload type 922 definition[RFCXXXX]. 924 * Measurement Point(s) with Potential Measurement Domain: See 925 section 3, 2nd paragraph [RFCXXXX]. 927 * Measurement Timing: See section 3, 3rd paragraph [RFCXXXX] for 928 measurement timing and section 3.1 [RFCXXXX] for Interval 929 Metric flag. 931 * Use and applications: See section 1.4 [RFCXXXX]. 933 * Reporting model: See RFC3611. 935 e. Channel Identifier Metric 937 * Metric Name: Audio Channel Identifier in RTP 939 * Metric Description: It is used to identify each audio channel 940 carried in the same RTP stream. For more details, see section 941 3.2.2, channel identifier definition. 943 * Method of Measurement or Calculation: See section 3.2.2, 944 Channel Identifier definition [RFCXXXX]. 946 * Units of Measurement: See section 3.2.2, channel identifier 947 definition[RFCXXXX]. 949 * Measurement Point(s) with Potential Measurement Domain: See 950 section 3, 2nd paragraph [RFCXXXX]. 952 * Measurement Timing: See section 3, 3rd paragraph [RFCXXXX] for 953 measurement timing and section 3.1 [RFCXXXX] for Interval 954 Metric flag. 956 * Use and applications: See section 1.4 [RFCXXXX]. 958 * Reporting model: See RFC3611. 960 Appendix B. Change Log 962 B.1. draft-ietf-xrblock-rtcp-xr-qoe-15 964 The following are the major changes compared to previous version: 965 o Some Editorial Changes. 967 B.2. draft-ietf-xrblock-rtcp-xr-qoe-14 969 The following are the major changes compared to previous version: 970 o Add some texts to address IESG review comments. 972 B.3. draft-ietf-xrblock-rtcp-xr-qoe-10 974 The following are the major changes compared to previous version: 975 o Replace QoE metrics with MoS metrics. 977 B.4. draft-ietf-xrblock-rtcp-xr-qoe-09 979 The following are the major changes compared to previous version: 980 o Address comments recieved from WGLC, PM-DIR Review and SDP review. 981 o Change an existing SDP attribute 'extmap' to new SDP attribute 982 'calgextmap' and add new SDP attribute registry. 983 o Add Reference to G.107.1, P.862.1, P.862.2 and P.863 for new 984 calculation algorithms. 985 o Add MoS type attribute to distinguish different MoS type. 986 o Other Editorial changes. 988 B.5. draft-ietf-xrblock-rtcp-xr-qoe-08 990 The following are the major changes compared to previous version: 991 o Remove mostype attribute from SDP extension since it can inferred 992 from payload type. 993 o Clarify mosref attribute usage in the O/A. 995 B.6. draft-ietf-xrblock-rtcp-xr-qoe-07 997 The following are the major changes compared to previous version: 998 o Some editorial changes to get in line with burst gap related 999 draft. 1000 o Add an appendix to apply RFC6390 template. 1002 B.7. draft-ietf-xrblock-rtcp-xr-qoe-06 1004 The following are the major changes compared to previous two 1005 versions: 1006 o A few Contact information update. 1007 o A few Acknowledgement section update. 1009 B.8. draft-ietf-xrblock-rtcp-xr-qoe-04 1011 The following are the major changes compared to previous version: 1012 o Split two references P.NAMS and P.NBAMS into four references. 1013 o SDP signaling update. 1014 o Add one example to explain User QoE evaluation for video stream 1016 B.9. draft-ietf-xrblock-rtcp-xr-qoe-03 1018 The following are the major changes compared to previous version: 1019 o Add one new reference to support TTC JJ201.01. 1020 o Update two references P.NAMS and P.NBAMS. 1021 o Other Editorial changes based on comments applied to PDV and Delay 1022 drafts. 1024 B.10. draft-ietf-xrblock-rtcp-xr-qoe-02 1026 The following are the major changes compared to previous version: 1027 o Remove leftmost second bit since it is ueeless. 1028 o Change 13bits MoS value field into 14 bits to increase MoS 1029 precision. 1030 o Fix some typo and make some editorial changes. 1032 B.11. draft-ietf-xrblock-rtcp-xr-qoe-01 1034 The following are the major changes compared to previous version: 1035 o Remove layered support from the QoE Metric draft. 1036 o Allocate 7 bits in the block header for payload type to indicate 1037 what type of payload format is in use and add associated 1038 definition of payload type. 1039 o Clarify using Payload Type to determine the appropriate channel 1040 mapping in the definition of Channel Identifier. 1042 B.12. draft-ietf-xrblock-rtcp-xr-qoe-00 1044 The following are the major changes compared to previous version: 1045 o Allocate one more bit in the single channel per SSC segment to get 1046 alignment with the other two segment type. 1048 Authors' Addresses 1050 Alan Clark 1051 Telchemy Incorporated 1052 2905 Premiere Parkway, Suite 280 1053 Duluth, GA 30097 1054 USA 1056 Email: alan.d.clark@telchemy.com 1058 Qin Wu 1059 Huawei 1060 101 Software Avenue, Yuhua District 1061 Nanjing, Jiangsu 210012 1062 China 1064 Email: sunseawq@huawei.com 1065 Roland Schott 1066 Deutsche Telekom 1067 Heinrich-Hertz-Strasse 3-7 1068 Darmstadt 64295 1069 Germany 1071 Email: Roland.Schott@telekom.de 1073 Glen Zorn 1074 Network Zen 1075 77/440 Soi Phoomjit, Rama IV Road 1076 Phra Khanong, Khlong Toie 1077 Bangkok 10110 1078 Thailand 1080 Phone: +66 (0) 87 502 4274 1081 Email: gwz@net-zen.net