idnits 2.17.1 draft-ietf-xrblock-rtcp-xr-pdv-07.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 (September 21, 2012) is 4234 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) == Unused Reference: 'RFC5234' is defined on line 553, but no explicit reference was found in the text -- Possible downref: Non-RFC (?) normative reference: ref. 'G.1020' == Outdated reference: A later version (-10) exists of draft-ietf-xrblock-rtcp-xr-meas-identity-06 ** Obsolete normative reference: RFC 4566 (Obsoleted by RFC 8866) ** Obsolete normative reference: RFC 5226 (Obsoleted by RFC 8126) == Outdated reference: A later version (-22) exists of draft-ietf-avtcore-monarch-13 Summary: 2 errors (**), 0 flaws (~~), 4 warnings (==), 2 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Audio/Video Transport Working Group A. Clark 3 Internet-Draft Telchemy 4 Intended status: Standards Track Q. Wu 5 Expires: March 25, 2013 Huawei 6 September 21, 2012 8 RTP Control Protocol (RTCP) Extended Report (XR) Block for Packet Delay 9 Variation Metric Reporting 10 draft-ietf-xrblock-rtcp-xr-pdv-07.txt 12 Abstract 14 This document defines an RTP Control Protocol (RTCP) Extended Report 15 (XR) block that allows the reporting of Packet Delay Variation 16 metrics for a range of RTP applications. 18 Status of this Memo 20 This Internet-Draft is submitted in full conformance with the 21 provisions of BCP 78 and BCP 79. 23 Internet-Drafts are working documents of the Internet Engineering 24 Task Force (IETF). Note that other groups may also distribute 25 working documents as Internet-Drafts. The list of current Internet- 26 Drafts is at http://datatracker.ietf.org/drafts/current/. 28 Internet-Drafts are draft documents valid for a maximum of six months 29 and may be updated, replaced, or obsoleted by other documents at any 30 time. It is inappropriate to use Internet-Drafts as reference 31 material or to cite them other than as "work in progress." 33 This Internet-Draft will expire on March 25, 2013. 35 Copyright Notice 37 Copyright (c) 2012 IETF Trust and the persons identified as the 38 document authors. All rights reserved. 40 This document is subject to BCP 78 and the IETF Trust's Legal 41 Provisions Relating to IETF Documents 42 (http://trustee.ietf.org/license-info) in effect on the date of 43 publication of this document. Please review these documents 44 carefully, as they describe your rights and restrictions with respect 45 to this document. Code Components extracted from this document must 46 include Simplified BSD License text as described in Section 4.e of 47 the Trust Legal Provisions and are provided without warranty as 48 described in the Simplified BSD License. 50 Table of Contents 52 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 53 1.1. Packet Delay Variation Metrics Block . . . . . . . . . . . 3 54 1.2. RTCP and RTCP XR Reports . . . . . . . . . . . . . . . . . 3 55 1.3. Performance Metrics Framework . . . . . . . . . . . . . . 3 56 1.4. Applicability . . . . . . . . . . . . . . . . . . . . . . 3 57 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 58 2.1. Standards Language . . . . . . . . . . . . . . . . . . . . 4 59 2.2. Notations . . . . . . . . . . . . . . . . . . . . . . . . 4 60 3. Packet Delay Variation Metrics Block . . . . . . . . . . . . . 5 61 3.1. Report Block Structure . . . . . . . . . . . . . . . . . . 5 62 3.2. Definition of Fields in PDV Metrics Block . . . . . . . . 5 63 3.3. Guidance on use of PDV metrics . . . . . . . . . . . . . . 9 64 3.4. Examples of use . . . . . . . . . . . . . . . . . . . . . 9 65 4. SDP Signaling . . . . . . . . . . . . . . . . . . . . . . . . 11 66 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 67 5.1. New RTCP XR Block Type value . . . . . . . . . . . . . . . 12 68 5.2. New RTCP XR SDP Parameter . . . . . . . . . . . . . . . . 12 69 5.3. Contact information for registrations . . . . . . . . . . 12 70 5.4. New registry of PDV types . . . . . . . . . . . . . . . . 12 71 6. Security Considerations . . . . . . . . . . . . . . . . . . . 14 72 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 15 73 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 16 74 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 17 75 9.1. Normative References . . . . . . . . . . . . . . . . . . . 17 76 9.2. Informative References . . . . . . . . . . . . . . . . . . 17 77 Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 19 78 A.1. draft-ietf-xrblock-rtcp-xr-pdv-06 . . . . . . . . . . . . 19 79 A.2. draft-ietf-xrblock-rtcp-xr-pdv-05 . . . . . . . . . . . . 19 80 A.3. draft-ietf-xrblock-rtcp-xr-pdv-04 . . . . . . . . . . . . 19 81 A.4. draft-ietf-xrblock-rtcp-xr-pdv-03 . . . . . . . . . . . . 19 82 A.5. draft-ietf-xrblock-rtcp-xr-pdv-02 . . . . . . . . . . . . 20 83 A.6. draft-ietf-xrblock-rtcp-xr-pdv-01 . . . . . . . . . . . . 20 84 A.7. draft-ietf-xrblock-rtcp-xr-pdv-00 . . . . . . . . . . . . 20 85 A.8. draft-ietf-avt-rtcp-xr-pdv-03 . . . . . . . . . . . . . . 20 86 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 21 88 1. Introduction 90 1.1. Packet Delay Variation Metrics Block 92 This draft defines a new block type to augment those defined in 93 [RFC3611], for use in a range of RTP applications. 95 The new block type provides information on Packet Delay Variation 96 (PDV) using one of several standard metrics,, for example, Mean 97 Absolute Packet Delay Variation 2 (MAPDV2) (Clause 6.2.3.2 of 98 [G.1020]), or 2-point PDV (Clause 6.2.4 of [Y.1540]). 100 The metrics belong to the class of transport metrics defined in 101 [MONARCH]. 103 1.2. RTCP and RTCP XR Reports 105 The use of RTCP for reporting is defined in [RFC3550]. [RFC3611] 106 defined an extensible structure for reporting using an RTCP Extended 107 Report (XR). This draft defines a new Extended Report block for use 108 with [RFC3550] and [RFC3611]. 110 1.3. Performance Metrics Framework 112 The Performance Metrics Framework [RFC6390] provides guidance on the 113 definition and specification of performance metrics. The RTP 114 Monitoring Architectures [MONARCH] provides guideline for reporting 115 block format using RTCP XR. The XR Block described in this document 116 are in accordance with the guidelines in [RFC6390] and [MONARCH]. 118 1.4. Applicability 120 These metrics are applicable to a wide range of RTP applications in 121 which the application streams are sensitive to delay 122 variation[RFC5481]. For example, applications could use the 123 measurements of these metrics to help adjust the size of adaptive 124 jitter buffers to improve performance. Network managers can use 125 these metrics to compare actual delay variation to targets (i.e., a 126 numerical objective or Service Level Agreement) to help ensure the 127 quality of real-time application performance. 129 2. Terminology 131 2.1. Standards Language 133 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 134 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 135 document are to be interpreted as described in RFC 2119 [RFC2119]. 137 2.2. Notations 139 This report block makes use of binary fractions. The terminology 140 used is 142 Numeric formats S X:Y 144 where S indicates a two's complement signed representation, X 145 the number of bits prior to the decimal place and Y the number 146 of bits after the decimal place. 148 Hence 8:8 represents an unsigned number in the range 0.0 to 149 255.996 with a granularity of 0.0039. S7:8 would represent the 150 range -127.996 to +127.996. 0:16 represents a proper binary 151 fraction with range 153 0.0 to 1 - 1/65536 = 0.9999847 155 though note that use of flag values at the top of the numeric 156 range slightly reduces this upper limit. For example, if the 157 16- bit values 0xfffe and 0xffff are used as flags for "over- 158 range" and "unavailable" conditions, a 0:16 quantity has range 160 0.0 to 1 - 3/65536 = 0.9999542 162 3. Packet Delay Variation Metrics Block 164 Metrics in this block report on packet delay variation in the stream 165 arriving at the RTP system. The measurement of these metrics are 166 made at the receiving end of the RTP stream. Instances of this 167 Metrics Block refer by Synchronization source (SSRC) to the separate 168 auxiliary Measurement Information block [MEASI] which contains 169 measurement intervals. This metric block relies on the measurement 170 interval in the Measurement Information block indicating the span of 171 the report and SHOULD be sent in the same compound RTCP packet as the 172 measurement information block. If the measurement interval is not 173 received for this metric block, this metric block MUST be discarded ( 174 See section 5.4 of[MONARCH]for timing details). 176 3.1. Report Block Structure 178 PDV metrics block 180 0 1 2 3 181 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7 182 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 183 | BT=NPDV | I |pdvtyp |Rsv| block length=4 | 184 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 185 | SSRC of Source | 186 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 187 | Pos PDV Threshold/Peak | Pos PDV Percentile | 188 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 189 | Neg PDV Threshold/Peak | Neg PDV Percentile | 190 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 191 | Mean PDV | Reserved | 192 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 194 Figure 1: Report Block Structure 196 3.2. Definition of Fields in PDV Metrics Block 198 Block type (BT): 8 bits 200 A Packet Delay Variation Metrics Report Block is identified by the 201 constant NPDV. 203 [Note to RFC Editor: please replace NPDV with the IANA provided 204 RTCP XR block type for this block.] 206 Interval Metric flag (I): 2 bit 208 This field is used to indicate whether the Packet Delay variation 209 metrics are Sampled, Interval or Cumulative metrics [MONARCH], 210 that is, whether the reported values applies to the most recent 211 measurement interval duration between successive metrics reports 212 (I=10) (the Interval Duration) or to the accumulation period 213 characteristic of cumulative measurements (I=11) (the Cumulative 214 Duration) or is a sampled instantaneous value (I=01) (Sampled 215 Value). The value I=00 is reserved, and MUST NOT be used. If the 216 value I=00 is received, it MUST be ignored by the receiver. 218 Packet Delay Variation Metric Type (pdvtyp): 4 bits 220 Packet Delay Variation Metric Type is of type enumerated and is 221 interpreted as Integer. This field is used to identify the Packet 222 Delay Variation Metric Type used in this report block, according 223 to the following code: 225 bits 014-011 227 0: MAPDV2, Clause 6.2.3.2 of [G.1020], 229 1: 2-point PDV, Clause 6.2.4 of [Y.1540]. 231 Rsv.: 2 bits 233 This field is reserved for future definition. In the absence of 234 such a definition, the bits in this field MUST be set to zero and 235 ignored by the receiver. 237 Block Length: 16 bits 239 The length of this report block in 32-bit words, minus one. For 240 the Packet Delay Variation Metrics block, the block length is 241 equal to 4. 243 SSRC of source: 32 bits 245 As defined in Section 4.1 of [RFC3611]. 247 Positive PDV Threshold/Peak: 16 bits 249 This field is associated with the Positive PDV percentile and 250 expressed in Milliseconds with numeric format S11:4. The term 251 Positive represents that the packets are arriving later than the 252 expected time. 254 If the measured value is more negative than -2047.9375 (the value 255 which would be coded as 0x8001), the value 0x8000 SHOULD be 256 reported to indicate an over-range negative measurement. If the 257 measured value is more positive than +2047.8125 (the value which 258 would be coded as 0x7FFD), the value 0x7FFE SHOULD be reported to 259 indicate an over-range positive measurement. If the measurement 260 is unavailable, the value 0x7FFF MUST be reported. 262 Positive PDV Percentile: 16 bits 264 The percentages of packets in the RTP stream for which individual 265 packet delays were less than the Positive PDV Threshold. It is 266 expressed in numeric format 8:8 with values from 0 to 100th 267 percentile. 269 If the measurement is unavailable, the value 0xFFFF MUST be 270 reported. 272 Negative PDV Threshold/Peak: 16 bits 274 This field is associated with the Negative PDV percentile and 275 expressed in Milliseconds with numeric format S11:4. The term 276 Negative represents that the packets are arriving earlier than the 277 expected time. 279 If the measured value is more negative than -2047.9375 (the value 280 which would be coded as 0x8001), the value 0x8000 SHOULD be 281 reported to indicate an over-range negative measurement. If the 282 measured value is more positive than +2047.8125 (the value which 283 would be coded as 0x7FFD), the value 0x7FFE SHOULD be reported to 284 indicate an over-range positive measurement. If the measurement 285 is unavailable, the value 0x7FFF MUST be reported. 287 Negative PDV Percentile: 16 bits 289 The percentages of packets in the RTP stream for which individual 290 packet delays were more than the Negative PDV Threshold. It is 291 expressed in numeric format 8:8 with values from 0 to 100th 292 percentile. 294 If the measurement is unavailable, the value 0xFFFF MUST be 295 reported. 297 If the PDV Type indicated is 2-point PDV and the Positive and 298 Negative PDV Percentiles are set to 100.0 then the Positive and 299 Negative Threshold/Peak PDV values are the peak values measured 300 during the reporting interval (which may be from the start of the 301 call for cumulative reports). In this case, the difference 302 between the Positive and Negative Threshold/Peak values defines 303 the range of 2-point PDV. 305 Mean PDV: 16 bits 307 The mean PDV value of data packets is expressed in milliseconds 308 with Numeric format S11:4 format. 310 For MAPDV2 this value is generated according to Clause 6.2.3.2 of 311 [G.1020]. For interval reports the MAPDV2 value is reset at the 312 start of the interval. 314 For 2-point PDV, the value reported is the mean of per-packet 315 2-point PDV values. This metric indicates the arrival time of the 316 first media packet of the session with respect to the mean of the 317 arrival times of every packet of the session. A single value of 318 the metric (for a single session) may not be useful by itself, but 319 its average over a number of sessions may be useful in diagnosing 320 media delay at session startup. For example, this might occur if 321 media packets are often delayed behind signalling packets due to 322 head-of-line blocking. 324 If the measured value is more negative than -2047.9375 (the value 325 which would be coded as 0x8001), the value 0x8000 SHOULD be 326 reported to indicate an over-range negative measurement. If the 327 measured value is more positive than +2047.8125 (the value which 328 would be coded as 0x7FFD), the value 0x7FFE SHOULD be reported to 329 indicate an over-range positive measurement. If the measurement 330 is unavailable, the value 0x7FFF MUST be reported. 332 Reserved: 16 bits 334 These bits are reserved for future definition. They MUST be set 335 to zero by the sender and ignored by the receiver. 337 3.3. Guidance on use of PDV metrics 339 This subsection provides informative guidance on when it might be 340 appropriate to use each of the PDV metric types. 342 MAPDV2 (Clause 6.2.3.2 of [G.1020]) is the envelope of instantaneous 343 (per-packet) delay when compared to the short term moving average 344 delay. This metric could be useful in determining residual 345 impairment when an RTP end system uses an adaptive de-jitter buffer 346 which tracks the average delay variation, provided the adaptive de- 347 jitter buffer have similar averaging behaviour as the MAPDV2 348 algorithm. 350 2-point PDV (Clause 6.2.4 of [Y.1540]) reports absolute packet delay 351 variation with respect to a defined reference packet transfer delay . 352 Note that the reference packet is generally selected as the packet 353 with minimum delay based on the most common criterion (See section 1 354 and section 5.1 of [RFC5481] ). In an RTP context, the two "points" 355 are at the sender (the synchronization source which applies RTP 356 timestamps) and at the receiver. The value of this metric for the 357 packet with index j is identical to the quantity D(i,j) defined in 358 Section 6.4.1 of [RFC3550] and the packet index i should be set equal 359 to the index of the reference packet for the metric in practice. The 360 metric includes the effect of the frequency offsets of clocks in both 361 the sender and receiver end systems, so it is useful mainly in 362 network where synchronisation is distributed. As well as measuring 363 packet delay variation in such networks, it may be used to ensure 364 that synchronisation is effective, for example where the network 365 carries ISDN data traffic over RTP [RFC4040]. The metric is likely 366 to be useful in networks which use fixed de-jitter buffering, because 367 it may be used to determine the length of the required de-jitter 368 buffer, or to determine if network performance has deteriorated such 369 that existing de-jitter buffers are too small to accommodate the 370 observed delay variation. 372 3.4. Examples of use 374 (b) To report MAPDV2 [G.1020]: 376 Pos PDV Threshold = 50.0; Pos PDV Percentile = 95.3; Neg PDV 377 Threshold = 50.0 (note this implies -50ms); Neg PDV Percentile 378 = 98.4; PDV type = 1 (MAPDV2) 380 causes average MAPDV2 to be reported in the Mean PDV field. 382 Note that implementations may either fix the reported 383 percentile and calculate the associated PDV level or may fix a 384 threshold PDV level and calculate the associated percentile. 386 From a practical implementation perspective it is simpler to 387 use the second of these approaches (except of course in the 388 extreme case of a 100% percentile). 390 (b) To report 2-point PDV [Y.1540]: 392 Pos PDV Threshold = 60 (note this implies +60ms); Pos PDV 393 Percentile = 96.3; Neg PDV Threshold = 0; Neg PDV Percentile = 394 0; PDV type = 1 (2-point PDV) 396 causes 2-point PDV to be reported in the Mean PDV field. 398 2-point PDV, according to [Y.1540] is the difference in delay 399 between the current packet and the referenced packet of the 400 stream. If the sending and receiving clocks are not 401 synchronized, this metric includes the effect of relative 402 timing drift. 404 4. SDP Signaling 406 [RFC3611] defines the use of SDP (Session Description Protocol) 407 [RFC4566] for signaling the use of XR blocks. XR blocks MAY be used 408 without prior signaling. 410 This section augments the SDP [RFC4566] attribute "rtcp-xr" defined 411 in [RFC3611] by providing an additional value of "xr-format" to 412 signal the use of the report block defined in this document. 414 xr-format =/ xr-pdv-block 416 xr-pdv-block = "pkt-dly-var" [ "," pdvtype ] [ "," nspec "," pspec ] 418 pdvtype = "pdv=" ( "0" ; MAPDV2 ITU-T G.1020 419 / "1" ; 2-point PDV ITU-T Y.1540 420 / 1*2DIGIT ) ;Value 2~15 are valid and 421 ;reserved for future use 422 nspec = ("nthr=" fixpoint) ; negative PDV threshold (ms) 423 / ("npc=" fixpoint ) ; negative PDV percentile 424 pspec = ("pthr=" fixpoint) ; positive PDV threshold (ms) 425 / ("ppc=" fixpoint) ; positive PDV percentile 427 fixpoint = 1*DIGIT "." 1*DIGIT ; fixed point decimal 428 DIGIT = 430 When SDP is used in offer-answer, a system sending SDP may request a 431 specific type of PDV measurement. In addition, they may state a 432 specific percentile or threshold value, and expect to receive the 433 corresponding threshold or percentile metric, respectively. The 434 system receiving the SDP SHOULD send the PDV metrics requested, but 435 if the metric is not available, the system receiving the SDP MUST 436 send the metric block with the flag value indicating that the metric 437 is unavailable. 439 5. IANA Considerations 441 New block types for RTCP XR are subject to IANA registration. For 442 general guidelines on IANA considerations for RTCP XR, refer to 443 [RFC3611]. 445 5.1. New RTCP XR Block Type value 447 This document assigns the block type value NPDV in the IANA "RTCP XR 448 Block Type Registry" to the "Packet Delay Variation Metrics Block". 450 [Note to RFC Editor: please replace NPDV with the IANA provided RTCP 451 XR block type for this block.] 453 5.2. New RTCP XR SDP Parameter 455 This document also registers a new parameter "pkt-dly-var" in the 456 "RTCP XR SDP Parameters Registry". 458 5.3. Contact information for registrations 460 The contact information for the registrations is: 462 Qin Wu (sunseawq@huawei.com) 464 101 Software Avenue, Yuhua District 465 Nanjing, Jiangsu 210012 466 China 468 5.4. New registry of PDV types 470 This document creates a new registry to be called "RTCP XR PDV block 471 - PDV type" as a sub-registry of the "RTP Control Protocol Extended 472 Reports (RTCP XR) Block Type Registry". Policies for this new 473 registry are as follows: 475 o The information required to support an assignment is an 476 unambiguous definition of the new metric, covering the base 477 measurements and how they are processed to generate the reported 478 metric. This should include the units of measurement, how values 479 of the metric are reported in the three 16-bit fields "Pos PDV 480 Threshold/Peak", "Neg PDV Threshold/Peak" and "Mean PDV" within 481 the report block, and how the metric uses the two 16-bit fields 482 "Pos PDV Percentile" and "Neg PDV Percentile". 484 o The review process for the registry is "Specification Required" as 485 described in Section 4.1 of [RFC5226]. 487 o Entries in the registry are integers. The valid range is 0 to 15 488 corresponding to the 4-bit field "pdvtyp" in the block. Values 489 are to be recorded in decimal. 491 o Initial assignments are as follows: 493 * 0: MAPDV2, Clause 6.2.3.2 of [G.1020], 495 * 1: 2-point PDV, Clause 6.2.4 of [Y.1540] 497 6. Security Considerations 499 It is believed that this proposed RTCP XR report block introduces no 500 new security considerations beyond those described in [RFC3611]. 501 This block does not provide per-packet statistics so the risk to 502 confidentiality documented in Section 7, paragraph 3 of [RFC3611] 503 does not apply. 505 7. Contributors 507 Geoff Hunt wrote the initial version of this document. 509 8. Acknowledgments 511 The authors gratefully acknowledge the comments and contributions 512 made by Bruce Adams, Philip Arden, Amit Arora, Bob Biskner, Kevin 513 Connor, Claus Dahm, Randy Ethier, Roni Even, Jim Frauenthal, Albert 514 Higashi, Tom Hock, Shane Holthaus, Paul Jones, Rajesh Kumar, Keith 515 Lantz, Mohamed Mostafa, Amy Pendleton, Colin Perkins, Mike Ramalho, 516 Ravi Raviraj, Albrecht Schwarz, Tom Taylor, and Hideaki Yamada,Jing 517 Zhao,Kevin Gross, Colin Perkins, Charles Eckel, Glen Zorn,Shida 518 Schubert, Benoit Claise, Adrian Farrel, Pete Resnick. 520 9. References 522 9.1. Normative References 524 [G.1020] ITU-T, "ITU-T Rec. G.1020, Performance parameter 525 definitions for quality of speech and other voiceband 526 applications utilizing IP networks", July 2006. 528 [MEASI] Hunt, G., "Measurement Identity and information Reporting 529 using SDES item and XR Block", 530 ID draft-ietf-xrblock-rtcp-xr-meas-identity-06, 531 April 2012. 533 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 534 Requirement Levels", March 1997. 536 [RFC3550] Schulzrinne, H., "RTP: A Transport Protocol for Real-Time 537 Applications", RFC 3550, July 2003. 539 [RFC3611] Friedman, T., Caceres, R., and A. Clark, "RTP Control 540 Protocol Extended Reports (RTCP XR)", November 2003. 542 [RFC4040] Kreuter, R., "RTP Payload Format for a 64 kbit/s 543 Transparent Call", April 2005. 545 [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session 546 Description Protocol", July 2006. 548 [RFC5226] Narten, T., "Guidelines for Writing an IANA Considerations 549 Section in RFCs", May 2008. 551 BCP 26 553 [RFC5234] Crocker, D. and P. Overell, "Augmented BNF for Syntax 554 Specifications: ABNF", January 2008. 556 [Y.1540] ITU-T, "ITU-T Rec. Y.1540, IP packet transfer and 557 availability performance parameters", November 2007. 559 9.2. Informative References 561 [MONARCH] Hunt, G., "Monitoring Architectures for RTP", 562 ID draft-ietf-avtcore-monarch-13, May 2012. 564 [RFC5481] Morton, A. and B. Claise, "Packet Delay Variation 565 Applicability Statement", RFC 5481, March 2009. 567 [RFC6390] Clark, A. and B. Claise, "Framework for Performance Metric 568 Development", RFC 6390, October 2011. 570 Appendix A. Change Log 572 Note to the RFC-Editor: please remove this section prior to 573 publication as an RFC. 575 A.1. draft-ietf-xrblock-rtcp-xr-pdv-06 577 The following are the major changes to previous version 578 draft-ietf-xrblock-rtcp-xr-pdv-05: 580 o Editorial change based on IESG Review. 582 o SDP element update based on pete's suggestion. 584 o Clarify the value of PDV in the applicability section. 586 o Clarify measurement point and timing in section 3. 588 A.2. draft-ietf-xrblock-rtcp-xr-pdv-05 590 The following are the major changes to previous version 591 draft-ietf-xrblock-rtcp-xr-pdv-04: 593 o Move Geoff Hunt from author list to Contributors section based on 594 his suggestion. 596 A.3. draft-ietf-xrblock-rtcp-xr-pdv-04 598 The following are the major changes to previous version 599 draft-ietf-xrblock-rtcp-xr-pdv-03: 601 o Editorial changes based on Gen-Art Review and Secdir Review. 603 A.4. draft-ietf-xrblock-rtcp-xr-pdv-03 605 The following are the major changes to previous version 606 draft-ietf-xrblock-rtcp-xr-pdv-02: 608 o Make definition of pdvtype get alignment with IANA section. 610 o Make Guidance on use of PDV metrics get alignment with RFC5481. 612 o Other Editorial changes. 614 A.5. draft-ietf-xrblock-rtcp-xr-pdv-02 616 The following are the major changes to previous version 617 draft-ietf-xrblock-rtcp-xr-pdv-01: 619 o Updated references. 621 o Allocate one more bit for Interval metric flag to indicate sampled 622 metric can be used. 624 o Add a few clarification text for failure mode. 626 A.6. draft-ietf-xrblock-rtcp-xr-pdv-01 628 The following are the major changes to previous version 629 draft-ietf-xrblock-rtcp-xr-pdv-00: 631 o Fix typos or nits in the definition of Negative PDV Threshold/ 632 Peak. 634 o Fix nits in Numeric format S7:8. 636 o remove the text that is relevant to tag field. 638 o Add text in SDP signaling section to clarify indicationof metric 639 unavailable. 641 A.7. draft-ietf-xrblock-rtcp-xr-pdv-00 643 The following are the major changes to previous version 644 draft-ietf-avt-rtcp-xr-pdv-03: 646 o Updated references. 648 A.8. draft-ietf-avt-rtcp-xr-pdv-03 650 The following are the major changes to previous version : 652 o Changed BNF for SDP following Christian Groves' and Tom Taylor's 653 comments (4th and 5th May 2009). 655 o Updated references. 657 Authors' Addresses 659 Alan Clark 660 Telchemy Incorporated 661 2905 Premiere Parkway, Suite 280 662 Duluth, GA 30097 663 USA 665 Email: alan.d.clark@telchemy.com 667 Qin Wu 668 Huawei 669 101 Software Avenue, Yuhua District 670 Nanjing, Jiangsu 210012 671 China 673 Email: sunseawq@huawei.com