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Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) ** Obsolete normative reference: RFC 4566 (Obsoleted by RFC 8866) == Outdated reference: A later version (-14) exists of draft-ietf-xrblock-rtcp-xr-burst-gap-discard-06 == Outdated reference: A later version (-12) exists of draft-ietf-xrblock-rtcp-xr-burst-gap-loss-04 == Outdated reference: A later version (-15) exists of draft-ietf-xrblock-rtcp-xr-discard-09 Summary: 1 error (**), 0 flaws (~~), 4 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group G. Zorn, Ed. 3 Internet-Draft Network Zen 4 Intended status: Standards Track R. Schott 5 Expires: May 30, 2013 Deutsche Telekom 6 Q. Wu 7 R. Huang 8 Huawei 9 November 26, 2012 11 RTP Control Protocol (RTCP) Extended Report (XR) Blocks for Summary 12 Statistics Metrics Reporting 13 draft-ietf-xrblock-rtcp-xr-summary-stat-03 15 Abstract 17 This document defines three RTP Control Protcol (RTCP) Extended 18 Report (XR) Blocks and associated SDP parameters that allow the 19 reporting of loss, duplication and discard summary statistics metrics 20 in a range of RTP applications. 22 Status of this Memo 24 This Internet-Draft is submitted in full conformance with the 25 provisions of BCP 78 and BCP 79. 27 Internet-Drafts are working documents of the Internet Engineering 28 Task Force (IETF). Note that other groups may also distribute 29 working documents as Internet-Drafts. The list of current Internet- 30 Drafts is at http://datatracker.ietf.org/drafts/current/. 32 Internet-Drafts are draft documents valid for a maximum of six months 33 and may be updated, replaced, or obsoleted by other documents at any 34 time. It is inappropriate to use Internet-Drafts as reference 35 material or to cite them other than as "work in progress." 37 This Internet-Draft will expire on May 30, 2013. 39 Copyright Notice 41 Copyright (c) 2012 IETF Trust and the persons identified as the 42 document authors. All rights reserved. 44 This document is subject to BCP 78 and the IETF Trust's Legal 45 Provisions Relating to IETF Documents 46 (http://trustee.ietf.org/license-info) in effect on the date of 47 publication of this document. Please review these documents 48 carefully, as they describe your rights and restrictions with respect 49 to this document. Code Components extracted from this document must 50 include Simplified BSD License text as described in Section 4.e of 51 the Trust Legal Provisions and are provided without warranty as 52 described in the Simplified BSD License. 54 Table of Contents 56 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 57 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 58 2.1. Standards Language . . . . . . . . . . . . . . . . . . . . 3 59 3. Transport Related End System Metrics . . . . . . . . . . . . . 4 60 3.1. Burst/Gap Loss Summary Statistics Block . . . . . . . . . 4 61 3.1.1. Report Block Structure . . . . . . . . . . . . . . . . 4 62 3.1.2. Definition of Fields in Loss Summary Statistics 63 Block . . . . . . . . . . . . . . . . . . . . . . . . 4 64 3.2. Burst/Gap Discard Summary Statistics Block . . . . . . . . 6 65 3.2.1. Report Block Structure . . . . . . . . . . . . . . . . 7 66 3.2.2. Definition of Fields inBurst/Gap Discard Summary 67 Statistics Block . . . . . . . . . . . . . . . . . . . 7 68 4. Application Level Metrics . . . . . . . . . . . . . . . . . . 8 69 4.1. Frame Impairment Statistics Summary Block . . . . . . . . 8 70 4.1.1. Report Block Structure . . . . . . . . . . . . . . . . 9 71 4.1.2. Definition of Fields in Frame Impairment Summary 72 Statistics Block . . . . . . . . . . . . . . . . . . . 9 73 5. SDP Signaling . . . . . . . . . . . . . . . . . . . . . . . . 11 74 5.1. SDP rtcp-xr-attrib Attribute Extension . . . . . . . . . . 11 75 5.2. Offer/Answer Usage . . . . . . . . . . . . . . . . . . . . 11 76 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 77 6.1. New RTCP XR Block Type values . . . . . . . . . . . . . . 11 78 6.2. New RTCP XR SDP Parameters . . . . . . . . . . . . . . . . 12 79 6.3. Contact information for registrations . . . . . . . . . . 12 80 7. Security Considerations . . . . . . . . . . . . . . . . . . . 12 81 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 12 82 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13 83 9.1. Normative References . . . . . . . . . . . . . . . . . . . 13 84 9.2. Informative References . . . . . . . . . . . . . . . . . . 13 85 Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 14 86 A.1. draft-ietf-xrblock-rtcp-xr-summary-stat-02 . . . . . . . . 14 87 A.2. draft-ietf-xrblock-rtcp-xr-summary-stat-01 . . . . . . . . 14 88 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 14 90 1. Introduction 92 This draft defines three new block types to augment those defined in 93 Freidman, et al. [RFC3611] for use in a range of RTP applications. 95 The first two block types support the reporting of burst gap loss/ 96 discard summary statistics including packet loss/discard proportion, 97 mean and variance and belong to the class of transport-related end 98 system metrics defined in Wu, Hunt & Arden [RFC6792]. These two 99 blocks are intended to be used in conjunction with information from 100 the Burst Gap Loss metric block or Burst Gap Discard metric block, 101 and on which these two block therefore depend. The metrics in the 102 Burst Gap Loss block or Burst Gap Discard metric block can be used 103 independently of the metrics defined in the first two blocks, 104 however. These two blocks reflect transient IP problems that affect 105 user experience and can be used to influence sender strategies to 106 mitigate the problem. 108 To form an accurate assessment of users' quality of experience, it is 109 therefore necessary to know not just overall rates of packet loss/ 110 discard, but also which frame types were affected. The third block 111 supports the reporting of detailed statistics for each frame type, 112 including the number of frames received, lost and discarded of each 113 frame type in the Group of Pictures (GOP) and additional data 114 allowing the calculation of statistical parameters (e.g.,the 115 proportion of each frame type impaired by packet loss and discard). 116 The metrics defined in this block belong to the class of application 117 layer metrics defined in Wu, Hunt & Arden [RFC6792]. 119 2. Terminology 121 2.1. Standards Language 123 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 124 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 125 document are to be interpreted as described in RFC 2119 [RFC2119]. 127 In addition, the following terms are defined: 129 Picture Type 131 Picture Types used in the different video algorithms are composed 132 of the Key frame and Derived frames. The Key frame is also called 133 a reference frame and used as a reference for predicting other 134 pictures. It is coded without prediction from other pictures. 135 Derived frames are derived from a Key frame using a prediction 136 algorithm. 138 3. Transport Related End System Metrics 140 3.1. Burst/Gap Loss Summary Statistics Block 142 The metrics described here are intended to be used as described in 143 this section, in conjunction with information from the Measurement 144 Information block [RFC6776] (which MUST be present in the same RTCP 145 packet as the Burst/Gap Loss block) and also with the metric 146 "cumulative number of packets lost" provided in standard RTCP 147 [RFC3550]. 149 These metrics provide information relevant to statistical parameters, 150 including burst loss rate, gap loss rate, burst duration mean, burst 151 duration variance and are calculated using burst gap loss metrics 152 defined in [I-D.ietf-xrblock-rtcp-xr-burst-gap-loss] and other 153 information which is sent together with this report block. 155 3.1.1. Report Block Structure 157 0 1 2 3 158 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 1 159 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 160 | BT=BGLSS | I | Reserved | block length | 161 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 162 | SSRC of Source | 163 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 164 | Burst Loss Rate | Gap Loss Rate | 165 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 166 | Burst duration Mean | Burst duration Variance | 167 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 169 3.1.2. Definition of Fields in Loss Summary Statistics Block 171 Block Type (BT): 8 bits 173 Burst/Gap Loss Summary Statistics Block is identified by the 174 constant . 176 Interval Metric flag (I): 2 bits 178 This field is used to indicate whether the Burst/Gap Loss Summary 179 Statistics metrics are Sampled, Interval or Cumulative metrics: 180 I=10: Interval Duration - the reported value applies to the 181 most recent measurement interval duration between successive 182 metrics reports. 184 I=11: Cumulative Duration - the reported value applies to the 185 accumulation period characteristic of cumulative measurements. 186 I=01: Sampled Value - the reported value is a sampled 187 instantaneous value. 189 Reserved: 6 bits 191 This field is reserved for future definition. In the absence of 192 such a definition, the bits in this field MUST be set to zero and 193 SHOULD be ignored by the receiver (See RFC6709 section 4.2). 195 Block Length: 16 bits 197 The constant 3, in accordance with the definition of this field in 198 Section 3 of RFC 3611 [RFC3611]. 200 SSRC of Source: 32 bits 202 As defined in Section 4.1 of RFC3611 [RFC3611]. 204 Burst Loss Rate: 16 bits 206 The fraction of packets lost during bursts since the beginning of 207 reception, expressed as a fixed point number with the binary point 208 at the left edge of the field. This value is calculated by 209 dividing Packets Loss in Bursts by Total Packets expected in 210 Bursts as follows: 212 Packets Loss in Bursts / Total Packets expected in Bursts 214 Gap Loss Rate: 16 bits 216 The fraction of packets lost during gaps since the beginning of 217 reception expressed as a fixed point number with the binary point 218 at the left edge of the field. This value is calculated by 219 dividing the difference between number of packets lost and Packets 220 lost in Bursts by the difference between Packets Expected and 221 Total Packets expected in Bursts as follows: 223 (number of packets lost - Packets Lost in Bursts) / (Packets 224 Expected - Total Packets expected in Bursts) 226 where "number of packets lost" is obtained from standard RTCP 227 [RFC3550] and Packets Expected is calculated as the difference 228 between "extended last sequence number" and "extended first 229 sequence number" (Interval or Cumulative) provided in the 230 Measurement Identity and Information block [RFC6776]. 232 Note that if the metric is to be calculated on an Interval basis, 233 a difference must be taken between the current and preceding 234 values of "cumulative number of packets lost" in RTCP, to obtain 235 the "number of packets lost" for the reporting interval. 237 Burst Duration Mean:16bits 239 The mean burst duration is obtained as the quotient: 241 mean = Sum of Burst Durations / Number of Bursts 243 where "Sum of Burst Durations" and "Number of Bursts" is obtained 244 from the RTCP XR Burst/Gap Loss Block 245 [I-D.ietf-xrblock-rtcp-xr-burst-gap-loss]. 247 Burst Duration Variance:16bits 249 The variance of the burst duration is obtained using the standard 250 result: 252 var = ( Sum of Squares of Burst Durations - Number of Bursts * 253 mean^2 ) / (Number of Bursts - 1) 255 where "Sum of Squares of Burst Durations" and "Number of Bursts"is 256 obtained from the RTCP XR Burst/Gap Loss Block 257 [I-D.ietf-xrblock-rtcp-xr-burst-gap-loss]. 259 3.2. Burst/Gap Discard Summary Statistics Block 261 The metrics described here are intended to be used as described in 262 this section, in conjunction with information from the Measurement 263 Identity block [RFC6776] (which MUST be present in the same RTCP 264 packet as the Burst/Gap Discard Summary Statistics block) and also 265 with the metric "number of packets discarded" provided in the RTCP XR 266 Discard Block [I-D.ietf-xrblock-rtcp-xr-discard]. The RTCP XR 267 Discard Block SHOULD be sent if the Burst/Gap Discard Summary 268 Statistics block is sent, but the converse does not apply. 270 These metrics provide information relevant to statistical parameters, 271 including burst discard rate, gap discard rate and are calculated 272 using burst gap loss metrics defined in 273 [I-D.ietf-xrblock-rtcp-xr-burst-gap-discard] and other information 274 which is sent together with this report block. 276 3.2.1. Report Block Structure 278 0 1 2 3 279 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 1 280 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 281 | BT=BGDSS | I | Reserved | block length | 282 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 283 | SSRC of Source | 284 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 285 | Burst Discard Rate | Gap Discard Rate | 286 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 288 3.2.2. Definition of Fields inBurst/Gap Discard Summary Statistics 289 Block 291 Block Type (BT): 8 bits 293 Burst/Gap Discard Summary Statistics Block is identified by the 294 constant . 296 Interval Metric Type (I): 2 bits 298 This field is used to indicate whether the Burst/Gap Discard 299 Summary Statistics metrics are Sampled, Interval or Cumulative 300 metrics: 301 I=10: Interval Duration - the reported value applies to the 302 most recent measurement interval duration between successive 303 metrics reports. 304 I=11: Cumulative Duration - the reported value applies to the 305 accumulation period characteristic of cumulative measurements. 306 I=01: Sampled Value - the reported value is a sampled 307 instantaneous value. 309 Reserved: 6 bits 311 This field is reserved for future definition. In the absence of 312 such a definition, the bits in this field MUST be set to zero and 313 SHOULD be ignored by the receiver (See RFC6709 section 4.2). 315 Block Length: 16 bits 317 The constant 2, in accordance with the definition of this field in 318 Section 3 of RFC 3611 [RFC3611]. 320 SSRC of Source: 32 bits 322 As defined in Section 4.1 of RFC3611 [RFC3611]. 324 Burst Discard Rate: 16 bits 326 The fraction of packets discarded during bursts since the 327 beginning of reception, expressed as a fixed point number with the 328 binary point at the left edge of the field. This value is 329 calculated by dividing Packets Discarded in Bursts by Total 330 Packets expected in Bursts as follows: 332 Packets Discarded in Bursts / Total Packets expected in Bursts 334 Gap Discard Rate: 16 bits 336 The fraction of packets discarded during gaps since the beginning 337 of reception expressed as a fixed point number with the binary 338 point at the left edge of the field. This value is calculated by 339 dividing the difference between number of packets discarded and 340 Packets Discarded in Bursts by the difference between Packets 341 Expected and Total Packets expected in Bursts as follows: 343 (number of packets discarded - Packets Discarded in Bursts) / 344 (Packets Expected - Total Packets expected in Bursts) 346 where "number of packets discarded" is obtained from the RTCP XR 347 Discard Count Block [I-D.ietf-xrblock-rtcp-xr-discard] and filled 348 with the total number of packets discarded due to both early and 349 late arrival(DT=3) and Packets Expected is calculated as the 350 difference between "extended last sequence number" and "extended 351 first sequence number" (Interval or Cumulative) provided in the 352 Measurement Information block [RFC6776]. In order for the Burst/ 353 Gap Discard Summary Statistics Block to be meaningful a single 354 instance of the Discard Count block with DT=3 and a single 355 instance of the Burst Gap Discard Block MUST be included in the 356 same RTCP compound packet as the Burst/Gap Discard Summary 357 Statistics Block. 359 4. Application Level Metrics 361 4.1. Frame Impairment Statistics Summary Block 363 This block reports statistics on which frame type were affected 364 beyond the information carried in the Statistics Summary Report Block 365 RTCP packet specified in the section 4.6 of RFC 3611 [RFC3611]. 366 Information is recorded about thenumber of frames received, lost 367 frames, duplicated frames and lost partial frames. Such information 368 can be useful for network management and video quality monitoring. 370 4.1.1. Report Block Structure 372 0 1 2 3 373 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 1 374 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 375 | BT=FISS |T| Reserved | block length | 376 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 377 | SSRC of Source | 378 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 379 | Begin_seq | End_seq | 380 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 381 | Number of frames received | 382 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 383 | Discarded_frames | 384 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 385 | Dup_frames | 386 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 387 | Lost_full_frames | 388 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 389 | Lost_partial_frames | 390 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 392 4.1.2. Definition of Fields in Frame Impairment Summary Statistics 393 Block 395 Block type (BT): 8 bits 397 Frame Impairment Statistics Summary Block is identified by the 398 constant . 400 Picture type indicator (T): 1 bit 402 This field is used to indicate the frame type to be reported. The 403 bit is set to 0 if the lost_full_frames, lost_partial_frames and 404 dup_frames fields contain Key frame (reference frame) counts or 1 405 if they contain Derivation frame counts. Note that if both the 406 Key frame and Derivation frame report are sent, they should be 407 sent in the same RTCP compound packet using two Frame Impairment 408 Summary Statistics Blocks. 410 Reserved: 7 bits 412 This field is reserved for future definition. In the absence of 413 such a definition, the bits in this field MUST be set to zero and 414 SHOULD be ignored by the receiver. 416 Block Length: 16 bits 418 The constant 7, in accordance with the definition of this field in 419 Section 3 of RFC 3611 [RFC3611]. 421 SSRC of Source: 32 bits 423 As defined in Section 4.1 of RFC3611 [RFC3611]. 425 Begin_seq: 16 bits 427 As defined in Section 4.1 of RFC 3611 [RFC3611]. 429 end_seq: 16 bits 431 As defined in Section 4.1 of RFC 3611 [RFC3611]. 433 Number of frames received:32 bits 435 A count of the number of frames received in the above sequence 436 number interval, estimated if necessary. If no frames have been 437 received then this count SHALL be set to zero. 439 Number of discarded frames (discarded_frames): 32 bits 441 Number of frames discarded in the above sequence number interval. 443 Number of duplicate frames (dup_frames): 32 bits 445 Number of duplicate frames received in the above sequence number 446 interval. 448 Number of full frames lost (lost_full_frames): 32 bits 450 If one frame is completely lost, this frame is regarded as one 451 lost full frame. The lost_full_frames is equivalent to the number 452 of full frames lost in the above sequence number interval. 454 Number of partial frames lost (lost_partial_frames): 32 bits 456 If one frame is partially lost, this frame is regarded as one lost 457 fractional frame. The value of the lost_partial_frames field is 458 equivalent to the number of partial frames lost in the above 459 sequence number interval. 461 5. SDP Signaling 463 RFC 3611 defines the use of SDP (Session Description Protocol) 464 [RFC4566] for signaling the use of XR blocks. XR blocks MAY be used 465 without prior signaling. 467 5.1. SDP rtcp-xr-attrib Attribute Extension 469 This section augments the SDP [RFC4566] attribute "rtcp-xr" defined 470 in Section 5.1 of RFC 3611 by providing three additional values of 471 "xr-format" to signal the use of the report block defined in this 472 document. 474 xr-format = / burst-gap-loss-stat 475 / burst-gap-discard-stat 476 / frame-impairment-stat 477 Burst-gap-loss-stat ="burst gap loss summary statistics" 478 Burst-gap-discard-stat="burst gap discard summary statistics" 479 Frame-impairment-stat="frame impairment summary statistics" 481 5.2. Offer/Answer Usage 483 When SDP is used in offer-answer context, the SDP Offer/Answer usage 484 defined in Section 5.2 of RFC 3611 applies. 486 6. IANA Considerations 488 New block types for RTCP XR are subject to IANA registration. For 489 general guidelines on IANA considerations for RTCP XR, refer to RFC 490 3611. 492 6.1. New RTCP XR Block Type values 494 This document assigns three new block type value in the RTCP XR Block 495 Type Registry: 497 Name: BGLSS 498 Long Name: Burst/Gap Loss Summsary Statistics Block 499 Value 500 Reference: Section 3.1 502 Name: BGDSS 503 Long Name: Burst/Gap Discard Summary Statistics Block 504 Value 505 Reference: Section 3.2 507 Name: FISS 508 Long Name: Frame Impairment Statistics Summary 509 Value 510 Reference: Section 4.1 512 6.2. New RTCP XR SDP Parameters 514 This document also registers three new SDP [RFC4566] parameters for 515 the "rtcp-xr" attribute in the RTCP XR SDP Parameters Registry: 517 * " burst-gap-loss-stat " 518 * " burst-gap-discard-stat " 519 * " frame-impairment-stat " 521 6.3. Contact information for registrations 523 The contact information for the registrations is: 525 Glen Zorn 526 Network Zen 527 227/358 Thanon Sanphawut 528 Bang Na, Bangkok 10260 529 Thailand 531 7. Security Considerations 533 The new RTCP XR report blocks proposed in this document introduces no 534 new security considerations beyond those described in RFC 3611. 536 8. Acknowledgements 538 The authors would like to thank Bill Ver Steeg, David R Oran, Ali 539 Begen, Colin Perkins, Roni Even, Youqing Yang, Wenxiao Yu, Yinliang 540 Hu, Jing Zhao and Ray van Brandenburg for their valuable comments and 541 suggestions on this document. 543 9. References 545 9.1. Normative References 547 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 548 Requirement Levels", BCP 14, RFC 2119, March 1997. 550 [RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V. 551 Jacobson, "RTP: A Transport Protocol for Real-Time 552 Applications", STD 64, RFC 3550, July 2003. 554 [RFC3611] Friedman, T., Caceres, R., and A. Clark, "RTP Control 555 Protocol Extended Reports (RTCP XR)", RFC 3611, 556 November 2003. 558 [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session 559 Description Protocol", RFC 4566, July 2006. 561 9.2. Informative References 563 [I-D.ietf-xrblock-rtcp-xr-burst-gap-discard] 564 Clark, A., Huang, R., and W. Wu, "RTP Control 565 Protocol(RTCP) Extended Report (XR) Block for Discard 566 Count metric Reporting", 567 draft-ietf-xrblock-rtcp-xr-burst-gap-discard-06 (work in 568 progress), October 2012. 570 [I-D.ietf-xrblock-rtcp-xr-burst-gap-loss] 571 Clark, A., Zhang, S., Zhao, J., and W. Wu, "RTP Control 572 Protocol (RTCP) Extended Report (XR) Block for Burst/Gap 573 Loss metric Reporting", 574 draft-ietf-xrblock-rtcp-xr-burst-gap-loss-04 (work in 575 progress), October 2012. 577 [I-D.ietf-xrblock-rtcp-xr-discard] 578 Clark, A., Zorn, G., and W. Wu, "RTP Control Protocol 579 (RTCP) Extended Report (XR) Block for Discard Count metric 580 Reporting", draft-ietf-xrblock-rtcp-xr-discard-09 (work in 581 progress), October 2012. 583 [RFC6776] Wu, Q., "Measurement Identity and information Reporting 584 using SDES item and XR Block", RFC 6776, August 2012. 586 [RFC6792] Hunt, G., Wu, Q., and P. Arden, "Monitoring Architectures 587 for RTP", RFC 6792, November 2012. 589 Appendix A. Change Log 591 Note to the RFC-Editor: please remove this section prior to 592 publication as an RFC. 594 A.1. draft-ietf-xrblock-rtcp-xr-summary-stat-02 596 The following are the major changes compared to 01: 597 o Modify texts to clarify the selection of discard count based on 598 discard count metric block. 600 A.2. draft-ietf-xrblock-rtcp-xr-summary-stat-01 602 The following are the major changes compared to 00: 603 o Outdated Reference update 604 o Add text to clarify the selection of discard count based on 605 discard count metric block. 606 o Revise Interval metric flag defintion for consistency. 607 o SDP text restructure 608 o Other editorial changes based on comments on the list. 610 Authors' Addresses 612 Glen Zorn (editor) 613 Network Zen 614 227/358 Thanon Sanphawut 615 Bang Na, Bangkok 10260 616 Thailand 618 Phone: +66 (0) 909-201060 619 Email: glenzorn@gmail.com 621 Roland Schott 622 Deutsche Telekom 623 Deutsche-Telekom-Allee 7 624 Darmstadt 64295 625 Germany 627 Email: Roland.Schott@telekom.de 628 Qin Wu 629 Huawei 630 101 Software Avenue, Yuhua District 631 Nanjing, Jiangsu 210012 632 China 634 Email: sunseawq@huawei.com 636 Rachel Huang 637 Huawei 638 101 Software Avenue, Yuhua District 639 Nanjing 210012 640 China 642 Email: Rachel@huawei.com