idnits 2.17.1 draft-ietf-xrblock-rtcp-xr-loss-conceal-04.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 == Using lowercase 'not' together with uppercase 'MUST', 'SHALL', 'SHOULD', or 'RECOMMENDED' is not an accepted usage according to RFC 2119. Please use uppercase 'NOT' together with RFC 2119 keywords (if that is what you mean). Found 'SHALL not' in this paragraph: Equivalently, a concealed second is one in which some Loss-type concealment has occurred. Buffer adjustment-type concealment SHALL not cause Concealed Seconds to be incremented, with the following exception. An implementation MAY cause Concealed Seconds to be incremented for 'emergency' buffer adjustments made during talkspurts. -- The document date (January 24, 2013) is 4108 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) ** Obsolete normative reference: RFC 4566 (Obsoleted by RFC 8866) Summary: 1 error (**), 0 flaws (~~), 2 warnings (==), 1 comment (--). 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 G. Zorn, Ed. 5 Expires: July 28, 2013 Network Zen 6 C. Bi 7 STTRI 8 Q. Wu, Ed. 9 Huawei 10 January 24, 2013 12 RTCP XR Report Block for Concealment metrics Reporting on Audio 13 Applications 14 draft-ietf-xrblock-rtcp-xr-loss-conceal-04.txt 16 Abstract 18 This document defines two RTCP XR Report Blocks that allows the 19 reporting of loss concealment metrics for audio applications of RTP. 21 Status of this Memo 23 This Internet-Draft is submitted in full conformance with the 24 provisions of BCP 78 and BCP 79. 26 Internet-Drafts are working documents of the Internet Engineering 27 Task Force (IETF). Note that other groups may also distribute 28 working documents as Internet-Drafts. The list of current Internet- 29 Drafts is at http://datatracker.ietf.org/drafts/current/. 31 Internet-Drafts are draft documents valid for a maximum of six months 32 and may be updated, replaced, or obsoleted by other documents at any 33 time. It is inappropriate to use Internet-Drafts as reference 34 material or to cite them other than as "work in progress." 36 This Internet-Draft will expire on July 28, 2013. 38 Copyright Notice 40 Copyright (c) 2013 IETF Trust and the persons identified as the 41 document authors. All rights reserved. 43 This document is subject to BCP 78 and the IETF Trust's Legal 44 Provisions Relating to IETF Documents 45 (http://trustee.ietf.org/license-info) in effect on the date of 46 publication of this document. Please review these documents 47 carefully, as they describe your rights and restrictions with respect 48 to this document. Code Components extracted from this document must 49 include Simplified BSD License text as described in Section 4.e of 50 the Trust Legal Provisions and are provided without warranty as 51 described in the Simplified BSD License. 53 Table of Contents 55 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 56 1.1. Loss Concealment and Concealment Seconds Metrics 57 Reporting Block . . . . . . . . . . . . . . . . . . . . . 3 58 1.2. RTCP and RTCP XR Reports . . . . . . . . . . . . . . . . . 4 59 1.3. Performance Metrics Framework . . . . . . . . . . . . . . 4 60 1.4. Applicability . . . . . . . . . . . . . . . . . . . . . . 4 61 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 62 2.1. Standards Language . . . . . . . . . . . . . . . . . . . . 5 63 3. Loss Concealment Block . . . . . . . . . . . . . . . . . . . . 6 64 3.1. Report Block Structure . . . . . . . . . . . . . . . . . . 6 65 3.2. Definition of Fields in Loss Concealment Report Block . . 6 66 4. Concealment Seconds Block . . . . . . . . . . . . . . . . . . 10 67 4.1. Report Block Structure . . . . . . . . . . . . . . . . . . 10 68 4.2. Definition of Fields in Concealed Seconds Metrics Block . 10 69 5. SDP Signaling . . . . . . . . . . . . . . . . . . . . . . . . 15 70 5.1. SDP rtcp-xr-attrib Attribute Extension . . . . . . . . . . 15 71 5.2. Offer/Answer Usage . . . . . . . . . . . . . . . . . . . . 15 72 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 16 73 6.1. New RTCP XR Block Type values . . . . . . . . . . . . . . 16 74 6.2. New RTCP XR SDP Parameters . . . . . . . . . . . . . . . . 16 75 6.3. Contact information for registrations . . . . . . . . . . 16 76 7. Security Considerations . . . . . . . . . . . . . . . . . . . 17 77 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 18 78 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 19 79 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 20 80 10.1. Normative References . . . . . . . . . . . . . . . . . . . 20 81 10.2. Informative References . . . . . . . . . . . . . . . . . . 20 82 Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 21 83 A.1. draft-ietf-xrblock-rtcp-xr-loss-conceal-04 . . . . . . . . 21 84 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 22 86 1. Introduction 88 1.1. Loss Concealment and Concealment Seconds Metrics Reporting Block 90 At any instant, the audio output at a receiver may be classified as 91 either 'normal' or 'concealed'. 'Normal' refers to playout of audio 92 payload received from the remote end, and also includes locally 93 generated signals such as announcements, tones and comfort noise. 94 Concealment refers to playout of locally-generated signals used to 95 mask the impact of network impairments or to reduce the audibility of 96 jitter buffer adaptations. 98 This draft defines two new concealment related block types to augment 99 those defined in [RFC3611] for use in a range of RTP applications. 101 The first block type provides metrics for actions taken by the 102 receiver to mitigate the effect of packet loss and packet discard. 103 Specifically, the first metric (On-Time Playout Duration) reports the 104 duration of normal playout of data which the receiver obtained from 105 the sender's stream. A second metric (Loss Concealment Duration) 106 reports the total time during which the receiver played out media 107 data which was manufactured locally, because the sender's data for 108 these periods was not available due to packet loss or discard. A 109 similar metric (Buffer Adjustment Concealment Duration) reports the 110 duration of playout of locally-manufactured data replacing data which 111 is unavailable due to adaptation of an adaptive de-jitter buffer. 112 Further metrics (Playout Interrupt Count and Mean Playout Interrupt 113 Size) report the number of times normal playout was interrupted, and 114 the mean duration of these interruptions. 116 Loss Concealment Duration and Buffer Adjustment Concealment Duration 117 are reported separately because buffer adjustment is typically 118 arranged to occur in silence periods so may have very little impact 119 on user experience, whilst loss concealment may occur at any time. 121 The second block type provides metrics for concealment. 122 Specifically, the first metric (Unimpaired Seconds) reports the 123 number of whole seconds occupied only with normal playout of data 124 which the receiver obtained from the sender's stream. The second 125 metric (Concealed Seconds) reports the number of whole seconds during 126 which the receiver played out any locally-generated media data. A 127 third metric (Severely Concealed Seconds) reports the number of whole 128 seconds during which the receiver played out locally-generated data 129 for more than SCS Threshold (ms). 131 These metrics belongs to the class of transport-related terminal 132 metrics defined in [RFC6792]. 134 1.2. RTCP and RTCP XR Reports 136 The use of RTCP for reporting is defined in [RFC3550]. [RFC3611] 137 defined an extensible structure for reporting using an RTCP Extended 138 Report (XR). This draft defines a new Extended Report block that 139 MUST be used as defined in [RFC3550] and [RFC3611]. 141 1.3. Performance Metrics Framework 143 The Performance Metrics Framework [RFC6390] provides guidance on the 144 definition and specification of performance metrics. The RTP 145 Monitoring Architectures [RFC6792] provides guideline for reporting 146 block format using RTCP XR. The Metrics Block described in this 147 document are in accordance with those guidelines. 149 1.4. Applicability 151 These metrics are only applicable to audio applications of RTP. 153 2. Terminology 155 2.1. Standards Language 157 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 158 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 159 document are to be interpreted as described in RFC2119 [RFC2119]. 161 3. Loss Concealment Block 163 3.1. Report Block Structure 165 Loss Concealment metrics block 167 0 1 2 3 168 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 7 169 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 170 | BT=NLC | I |plc| rsv. | block length=5 | 171 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 172 | SSRC of Source | 173 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 174 | On-time Playout Duration | 175 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 176 | Loss Concealment Duration | 177 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 178 | Buffer Adjustment Concealment Duration | 179 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 180 | Playout Interrupt Count | Mean Playout Interrupt Size | 181 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 183 Figure 1: Report Block Structure 185 3.2. Definition of Fields in Loss Concealment Report Block 187 Block type (BT): 8 bits 189 A Loss Concealment Metrics Report Block is identified by the 190 constant NLC. 192 [Note to RFC Editor: please replace NLC with the IANA provided 193 RTCP XR block type for this block.] 195 Interval Metric flag (I): 2 bit 197 This field is used to indicate whether the Loss Concealment 198 metrics are Sampled, Interval or Cumulative metrics: 200 I=10: Interval Duration - the reported value applies to the 201 most recent measurement interval duration between successive 202 metrics reports. 204 I=11: Cumulative Duration - the reported value applies to the 205 accumulation period characteristic of cumulative measurements. 207 I=01: Sampled Value - the reported value is a sampled 208 instantaneous value. 210 Packet Loss Concealment Method (plc): 2 bits 212 This field is used to identify the packet loss concealment method 213 in use at the receiver, according to the following code: 215 bits 014-015 217 0 = silence insertion 219 1 = simple replay, no attenuation 221 2 = simple replay, with attenuation 223 3 = enhanced 225 Other values reserved 227 Reserved (resv): 4 bits 229 These bits are reserved. They MUST be set to zero by senders and 230 ignored by receivers (See [RFC6709] section 4.2). 232 block length: 16 bits 234 The length of this report block in 32-bit words, minus one. For 235 the Loss Concealment block, the block length is equal to 5. 237 SSRC of source: 32 bits 239 As defined in Section 4.1 of [RFC3611]. 241 On-time Playout Duration (ms): 32 bits 243 'On-time' playout is the uninterrupted, in-sequence playout of 244 valid decoded audio information originating from the remote 245 endpoint. This includes comfort noise during periods of remote 246 talker silence, if VAD is used, and locally generated or 247 regenerated tones and announcements. 249 An equivalent definition is that on-time playout is playout of any 250 signal other than those used for concealment. 252 On-time playout duration MUST include both speech and silence 253 intervals, whether VAD is used or not. This duration is reported 254 in millisecond units. 256 If the measured value exceeds 0xFFFFFFFD, the value 0xFFFFFFFE 257 MUST be reported to indicate an over-range measurement. If the 258 measurement is unavailable, the value 0xFFFFFFFF MUST be reported. 260 Loss Concealment Duration (ms): 32 bits 262 The duration, in milliseconds, of audio playout corresponding to 263 Loss-type concealment. 265 Loss-type concealment is reactive insertion or deletion of samples 266 in the audio playout stream due to effective frame loss at the 267 audio decoder. "Effective frame loss" is the event in which a 268 frame of coded audio is simply not present at the audio decoder 269 when required. In this case, substitute audio samples are 270 generally formed, at the decoder or elsewhere, to reduce audible 271 impairment. 273 If the measured value exceeds 0xFFFFFFFD, the value 0xFFFFFFFE 274 MUST be reported to indicate an over-range measurement. If the 275 measurement is unavailable, the value 0xFFFFFFFF MUST be reported. 277 Buffer Adjustment Concealment Duration (ms): 32 bits 279 The duration, in milliseconds, of audio playout corresponding to 280 Buffer Adjustment-type concealment, if known. 282 If the measured value exceeds 0xFFFFFFFD, the value 0xFFFFFFFE 283 MUST be reported to indicate an over-range measurement. If the 284 measurement is unavailable, the value 0xFFFFFFFF MUST be reported. 286 Buffer Adjustment-type concealment is proactive or controlled 287 insertion or deletion of samples in the audio playout stream due 288 to jitter buffer adaptation, re-sizing or re-centering decisions 289 within the endpoint. 291 Because this insertion is controlled, rather than occurring 292 randomly in response to losses, it is typically less audible than 293 loss-type concealment. For example, jitter buffer adaptation 294 events may be constrained to occur during periods of talker 295 silence, in which case only silence duration is affected, or 296 sophisticated time-stretching methods for insertion/deletion 297 during favorable periods in active speech may be employed. 299 Concealment events which cannot be classified as Buffer 300 Adjustment- type MUST be classified as Loss-type. 302 Playout Interrupt Count: 16 bits 304 The number of interruptions to normal playout which occurred 305 during the reporting period. 307 If the measured value exceeds 0xFFFD, the value 0xFFFE MUST be 308 reported to indicate an over-range measurement. If the 309 measurement is unavailable, the value 0xFFFF MUST be reported. 311 Mean Playout Interrupt Size (ms): 16 bits 313 The mean duration, in ms, of interruptions to normal playout which 314 occurred during the reporting period. 316 If the measured value exceeds 0xFFFD, the value 0xFFFE MUST be 317 reported to indicate an over-range measurement. If the 318 measurement is unavailable, the value 0xFFFF MUST be reported. 320 4. Concealment Seconds Block 322 This sub-block provides a description of potentially audible 323 impairments due to lost and discarded packets at the endpoint, 324 expressed on a time basis analogous to a traditional PSTN T1/E1 325 errored seconds metric. 327 The following metrics are based on successive one second intervals as 328 declared by a local clock. This local clock does NOT need to be 329 synchronized to any external time reference. The starting time of 330 this clock is unspecified. Note that this implies that the same loss 331 pattern could result in slightly different count values, depending on 332 where the losses occur relative to the particular one-second 333 demarcation points. For example, two loss events occurring 50ms 334 apart could result in either one concealed second or two, depending 335 on the particular 1000 ms boundaries used. 337 The seconds in this sub-block are not necessarily calendar seconds. 338 At the tail end of a session, periods of time of less than 1000ms 339 shall be incorporated into these counts if they exceed 500ms and 340 shall be disregarded if they are less than 500ms. 342 4.1. Report Block Structure 344 Concealed Seconds metrics block 346 0 1 2 3 347 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 1 348 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 349 | BT=NCS | I |plc|Rserved| block length=4 | 350 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 351 | SSRC of Source | 352 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 353 | Unimpaired Seconds | 354 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 355 | Concealed Seconds | 356 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 357 | Severely Concealed Seconds | RESERVED | SCS Threshold | 358 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 360 Figure 1: Report Block Structure 362 4.2. Definition of Fields in Concealed Seconds Metrics Block 363 Block type (BT): 8 bits 365 A Concealed Seconds Metrics Report Block is identified by the 366 constant NCS. 368 [Note to RFC Editor: please replace NCS with the IANA provided 369 RTCP XR block type for this block.] 371 Interval Metric flag (I): 2 bit 373 This field is used to indicate whether the Concealment Seconds 374 metrics are Sampled, Interval or Cumulative metrics: 376 I=10: Interval Duration - the reported value applies to the 377 most recent measurement interval duration between successive 378 metrics reports. 380 I=11: Cumulative Duration - the reported value applies to the 381 accumulation period characteristic of cumulative measurements. 383 I=01: Sampled Value - the reported value is a sampled 384 instantaneous value. 386 Packet Loss Concealment Method (plc): 2 bits 388 This field is used to identify the packet loss concealment method 389 in use at the receiver, according to the following code: 391 bits 014-015 393 0 = silence insertion 395 1 = simple replay, no attenuation 397 2 = simple replay, with attenuation 399 3 = enhanced 401 Other values reserved 403 Reserved (resv): 4 bits 405 These bits are reserved. They MUST be set to zero by senders and 406 ignored by receivers (See [RFC6709] section 4.2). 408 Block Length: 16 bits 410 The length of this report block in 32-bit words, minus one. For 411 the Concealment Seconds block, the block length is equal to 4. 413 SSRC of source: 32 bits 415 As defined in Section 4.1 of [RFC3611]. 417 Unimpaired Seconds: 32 bits 419 A count of the number of unimpaired Seconds that have occurred. 421 An unimpaired Second is defined as a continuous period of 1000ms 422 during which no frame loss or discard due to late arrival has 423 occurred. Every second in a session must be classified as either 424 OK or Concealed. 426 Normal playout of comfort noise or other silence concealment 427 signal during periods of talker silence, if VAD [VAD] is used, 428 shall be counted as unimpaired seconds. 430 If the measured value exceeds 0xFFFFFFFD, the value 0xFFFFFFFE 431 MUST be reported to indicate an over-range measurement. If the 432 measurement is unavailable, the value 0xFFFFFFFF MUST be reported. 434 Concealed Seconds: 32 bits 436 A count of the number of Concealed Seconds that have occurred. 438 A Concealed Second is defined as a continuous period of 1000ms 439 during which any frame loss or discard due to late arrival has 440 occurred. 442 Equivalently, a concealed second is one in which some Loss-type 443 concealment has occurred. Buffer adjustment-type concealment 444 SHALL not cause Concealed Seconds to be incremented, with the 445 following exception. An implementation MAY cause Concealed 446 Seconds to be incremented for 'emergency' buffer adjustments made 447 during talkspurts. 449 Loss-type concealment is reactive insertion or deletion of samples 450 in the audio playout stream due to effective frame loss at the 451 audio decoder. "Effective frame loss" is the event in which a 452 frame of coded audio is simply not present at the audio decoder 453 when required. In this case, substitute audio samples are 454 generally formed, at the decoder or elsewhere, to reduce audible 455 impairment. 457 Buffer Adjustment-type concealment is proactive or controlled 458 insertion or deletion of samples in the audio playout stream due 459 to jitter buffer adaptation, re-sizing or re-centering decisions 460 within the endpoint. 462 Because this insertion is controlled, rather than occurring 463 randomly in response to losses, it is typically less audible than 464 loss-type concealment. For example, jitter buffer adaptation 465 events may be constrained to occur during periods of talker 466 silence, in which case only silence duration is affected, or 467 sophisticated time-stretching methods for insertion/deletion 468 during favorable periods in active speech may be employed. For 469 these reasons, buffer adjustment-type concealment MAY be exempted 470 from inclusion in calculations of Concealed Seconds and Severely 471 Concealed Seconds. 473 However, an implementation SHOULD include buffer-type concealment 474 in counts of Concealed Seconds and Severely Concealed Seconds if 475 the event occurs at an 'inopportune' moment, with an emergency or 476 large, immediate adaptation during active speech, or for 477 unsophisticated adaptation during speech without regard for the 478 underlying signal, in which cases the assumption of low-audibility 479 cannot hold. In other words, jitter buffer adaptation events 480 which may be presumed to be audible SHOULD be included in 481 Concealed Seconds and Severely Concealed Seconds counts. 483 Concealment events which cannot be classified as Buffer 484 Adjustment- type MUST be classified as Loss-type. 486 For clarification, the count of Concealed Seconds MUST include the 487 count of Severely Concealed Seconds. 489 If the measured value exceeds 0xFFFFFFFD, the value 0xFFFFFFFE 490 MUST be reported to indicate an over-range measurement. If the 491 measurement is unavailable, the value 0xFFFFFFFF MUST be reported. 493 Severely Concealed Seconds: 16 bits 495 A count of the number of Severely Concealed Seconds. 497 A Severely Concealed Second is defined as a non-overlapping period 498 of 1000 ms during which the cumulative amount of time that has 499 been subject to frame loss or discard due to late arrival, exceeds 500 the SCS Threshold. 502 If the measured value exceeds 0xFFFD, the value 0xFFFE MUST be 503 reported to indicate an over-range measurement. If the 504 measurement is unavailable, the value 0xFFFF MUST be reported. 506 Reserved: 8 bits 508 These bits are reserved. They MUST be set to zero by senders and 509 ignored by receivers (See [RFC6709] section 4.2). 511 SCS Threshold: 8 bits 513 The SCS Threshold defines the amount of time corresponding to lost 514 or discarded frames that must occur within a one second period in 515 order for the second to be classified as a Severely Concealed 516 Second. This is expressed in milliseconds and hence can represent 517 a range of 0.1 to 25.5 percent loss or discard. 519 A default threshold of 50ms (5% effective frame loss per second) 520 is suggested. 522 5. SDP Signaling 524 [RFC3611] defines the use of SDP (Session Description Protocol) 525 [RFC4566] for signaling the use of XR blocks. XR blocks MAY be used 526 without prior signaling. 528 5.1. SDP rtcp-xr-attrib Attribute Extension 530 This section augments the SDP attribute "rtcp-xr" [RFC3611] by 531 providing two additional values of "xr-format" to signal the use of 532 the report block defined in this document. 534 xr-format =/ xr-conceal-block 535 xr-format =/ xr-conc-sec-block 537 xr-conceal-block = "loss-conceal" 538 xr-conc-sec-block = "conc-sec" ["=" thresh] 540 thresh = 1*DIGIT ; threshold for SCS (ms) 541 DIGIT = %x30-39 543 5.2. Offer/Answer Usage 545 When SDP is used in offer-answer context, the SDP Offer/Answer usage 546 defined in [RFC3611] applies. 548 6. IANA Considerations 550 New block types for RTCP XR are subject to IANA registration. For 551 general guidelines on IANA considerations for RTCP XR, refer to 552 [RFC3611]. 554 6.1. New RTCP XR Block Type values 556 This document assigns two block type values in the IANA "RTCP XR 557 Block Type Registry": 559 Name: NLC 560 Long Name: Loss Concealment Block 561 Value 562 Reference: Section 3.1 564 Name: NCS 565 Long Name: Concealment Seconds Block 566 Value 567 Reference: Section 4.1 569 [Note to RFC Editor: please replace and with the RTCP XR 570 block type assigned by IANA for this block.] 572 6.2. New RTCP XR SDP Parameters 574 This document also registers two new parameters in the "RTCP XR SDP 575 Parameters Registry": 577 o "loss-conceal" 579 o "conc-sec" 581 6.3. Contact information for registrations 583 The contact information for the registrations is: 585 Qin Wu (sunseawq@huawei.com) 586 101 Software Avenue, Yuhua District 587 Nanjing, Jiangsu 210012 588 China 590 7. Security Considerations 592 It is believed that this proposed RTCP XR report block introduces no 593 new security considerations beyond those described in [RFC3611]. 594 This block does not provide per-packet statistics so the risk to 595 confidentiality documented in Section 7, paragraph 3 of [RFC3611] 596 does not apply. 598 8. Contributors 600 Geoff Hunt wrote the initial draft of this document. 602 9. Acknowledgements 604 The authors gratefully acknowledge reviews and feedback provided by 605 Bruce Adams, Philip Arden, Amit Arora, Bob Biskner, Kevin Connor, 606 Claus Dahm, Randy Ethier, Roni Even, Jim Frauenthal, Albert Higashi, 607 Tom Hock, Shane Holthaus, Paul Jones, Rajesh Kumar, Keith Lantz, 608 Mohamed Mostafa, Amy Pendleton, Colin Perkins, Mike Ramalho, Ravi 609 Raviraj, Albrecht Schwarz, Tom Taylor, and Hideaki Yamada. 611 10. References 613 10.1. Normative References 615 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 616 Requirement Levels", March 1997. 618 [RFC3550] Schulzrinne, H., "RTP: A Transport Protocol for Real-Time 619 Applications", RFC 3550, July 2003. 621 [RFC3611] Friedman, T., Caceres, R., and A. Clark, "RTP Control 622 Protocol Extended Reports (RTCP XR)", November 2003. 624 [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session 625 Description Protocol", July 2006. 627 10.2. Informative References 629 [RFC6390] Clark, A. and B. Claise, "Framework for Performance Metric 630 Development", RFC 6390, October 2011. 632 [RFC6709] Carpenter, B., Aboba, B., and S. Cheshire, "Design 633 Considerations for Protocol Extensions", RFC 6709, 634 September 2012. 636 [RFC6792] Hunt, G., "Monitoring Architectures for RTP", RFC 6792, 637 November 2012. 639 [VAD] "http://en.wikipedia.org/wiki/Voice_activity_detection". 641 Appendix A. Change Log 643 Note to the RFC-Editor: please remove this section prior to 644 publication as an RFC. 646 A.1. draft-ietf-xrblock-rtcp-xr-loss-conceal-04 648 The following are the major changes to previous version : 650 o Merge Concealment Seconds draft into this draft (i.e.,Loss 651 Concealment draft). 653 o Updated references. 655 Authors' Addresses 657 Alan Clark 658 Telchemy Incorporated 659 2905 Premiere Parkway, Suite 280 660 Duluth, GA 30097 661 USA 663 Email: alan.d.clark@telchemy.com 665 Glen Zorn (editor) 666 Network Zen 667 77/440 Soi Phoomjit, Rama IV Road 668 Phra Khanong, Khlong Toie 669 Bangkok 10110 670 Thailand 672 Phone: +66 (0) 87 502 4274 673 Email: gwz@net-zen.net 675 Claire Bi 676 Shanghai Research Institure of China Telecom Corporation Limited 677 No.1835,South Pudong Road 678 Shanghai 200122 679 China 681 Email: bijy@sttri.com.cn 683 Qin Wu (editor) 684 Huawei 685 101 Software Avenue, Yuhua District 686 Nanjing, Jiangsu 210012 687 China 689 Email: sunseawq@huawei.com