idnits 2.17.1 draft-ietf-xrblock-rtcp-xr-delay-08.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 (August 30, 2012) is 4251 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references to lower-maturity documents in RFCs) ** Obsolete normative reference: RFC 4566 (Obsoleted by RFC 8866) == Outdated reference: A later version (-10) exists of draft-ietf-xrblock-rtcp-xr-meas-identity-09 == Outdated reference: A later version (-22) exists of draft-ietf-avtcore-monarch-18 Summary: 1 error (**), 0 flaws (~~), 3 warnings (==), 1 comment (--).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 K. Gross 5 Expires: March 3, 2013 AVA Networks 6 Q. Wu 7 Huawei 8 August 30, 2012 10 RTCP XR Report Block for Delay metric Reporting 11 draft-ietf-xrblock-rtcp-xr-delay-08.txt 13 Abstract 15 This document defines an RTCP XR Report Block that allows the 16 reporting of Delay metrics for use in 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 3, 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 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 3. Delay Block . . . . . . . . . . . . . . . . . . . . . . . . . 5 60 3.1. Report Block Structure . . . . . . . . . . . . . . . . . . 5 61 3.2. Definition of Fields in Delay Metrics Report Block . . . . 5 62 4. SDP Signaling . . . . . . . . . . . . . . . . . . . . . . . . 8 63 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 64 5.1. New RTCP XR Block Type value . . . . . . . . . . . . . . . 9 65 5.2. New RTCP XR SDP Parameter . . . . . . . . . . . . . . . . 9 66 5.3. Contact information for registrations . . . . . . . . . . 9 67 6. Security Considerations . . . . . . . . . . . . . . . . . . . 10 68 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 11 69 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 12 70 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 13 71 9.1. Normative References . . . . . . . . . . . . . . . . . . . 13 72 9.2. Informative References . . . . . . . . . . . . . . . . . . 13 73 Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 14 74 A.1. draft-ietf-xrblock-rtcp-xr-delay-08 . . . . . . . . . . . 14 75 A.2. draft-ietf-xrblock-rtcp-xr-delay-07 . . . . . . . . . . . 14 76 A.3. draft-ietf-xrblock-rtcp-xr-delay-06 . . . . . . . . . . . 14 77 A.4. draft-ietf-xrblock-rtcp-xr-delay-05 . . . . . . . . . . . 14 78 A.5. draft-ietf-xrblock-rtcp-xr-delay-04 . . . . . . . . . . . 14 79 A.6. draft-ietf-xrblock-rtcp-xr-delay-03 . . . . . . . . . . . 14 80 A.7. draft-ietf-xrblock-rtcp-xr-delay-02 . . . . . . . . . . . 15 81 A.8. draft-ietf-xrblock-rtcp-xr-delay-01 . . . . . . . . . . . 15 82 A.9. draft-ietf-xrblock-rtcp-xr-delay-00 . . . . . . . . . . . 15 83 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 16 85 1. Introduction 87 1.1. Packet Delay Metrics Block 89 This draft defines a new block type to augment those defined in 90 [RFC3611] for use in a range of RTP applications. The new block type 91 supports the reporting of the mean, minimum and maximum values of the 92 network round-trip delay between RTP interfaces in peer RTP end 93 systems as measured, for example, using the RTCP method described in 94 [RFC3550]. It also supports reporting of the component of the round- 95 trip delay internal to the local RTP system. 97 The network metrics belong to the class of packet transport delay 98 metrics defined in [MONARCH]. 100 1.2. RTCP and RTCP XR Reports 102 The use of RTCP for reporting is defined in [RFC3550]. [RFC3611] 103 defined an extensible structure for reporting using an RTCP Extended 104 Report (XR). This draft defines a new Extended Report block that 105 MUST be used as defined in [RFC3550] and [RFC3611]. 107 1.3. Performance Metrics Framework 109 The Performance Metrics Framework [RFC6390] provides guidance on the 110 definition and specification of performance metrics. The RTP 111 Monitoring Architectures [MONARCH] provides guideline for reporting 112 block format using RTCP XR. The Metrics Block described in this 113 document are in accordance with the guidelines in [RFC6390] and 114 [MONARCH]. 116 1.4. Applicability 118 These metrics are applicable to a range of RTP applications in which 119 this report block would be useful, such as multimedia conferencing 120 and streaming audio and video. Knowledge of the round-trip delay and 121 delay characteristics can aid other receivers in sizing their receive 122 buffers and selecting a playout delay. The same information is also 123 valuable to network managers in troubleshooting network and user 124 experience issues. 126 2. Terminology 128 2.1. Standards Language 130 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 131 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 132 document are to be interpreted as described in RFC 2119 [RFC2119]. 134 3. Delay Block 136 Metrics in this block report on packet delay in the stream arriving 137 at the RTP system. Instances of this Metrics Block refer by 138 Synchronization source (SSRC) to the separate auxiliary Measurement 139 Information block [MEASI] which contains measurement intervals. This 140 metric block relies on the measurement interval in the Measurement 141 Information block indicating the span of the report and SHOULD be 142 sent in the same compound RTCP packet as the measurement information 143 block. If the measurement interval is not received in the same 144 compound RTCP packet as this metric block, this metric block SHOULD 145 be discarded. 147 3.1. Report Block Structure 149 Delay metrics block 151 0 1 2 3 152 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 7 153 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 154 | BT=NDEL | I | resv. | block length = 6 | 155 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 156 | SSRC of Source | 157 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 158 | Mean Network Round Trip Delay | 159 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 160 | Min Network Round Trip Delay | 161 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 162 | Max Network Round Trip Delay | 163 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 164 | End System Delay - Seconds (bit 0-31) | 165 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 166 | End System Delay - Fraction (bit 0-31) | 167 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 169 Figure 1: Report Block Structure 171 3.2. Definition of Fields in Delay Metrics Report Block 173 Block type (BT): 8 bits 175 A Delay Report Block is identified by the constant NDEL. 177 [Note to RFC Editor: please replace NDEL with the IANA provided 178 RTCP XR block type for this block.] 180 Interval Metric flag (I): 2 bit 182 This field is used to indicate whether the Delay metrics are 183 Sampled, Interval or Cumulative metrics, that is, whether the 184 reported values applies to the most recent measurement interval 185 duration between successive metrics reports (I=10) (the Interval 186 Duration) or to the accumulation period characteristic of 187 cumulative measurements (I=11) (the Cumulative Duration) or is a 188 sampled instantaneous value (I=01) (Sampled Value). 190 Reserved (resv): 6 bits 192 These bits are reserved. They MUST be set to zero by senders and 193 SHOULD be ignored by receivers. 195 block length: 16 bits 197 The length of this report block in 32-bit words, minus one. For 198 the Delay block, the block length is equal to 6. 200 SSRC of source: 32 bits 202 As defined in Section 4.1 of [RFC3611]. 204 Mean Network Round Trip Delay: 32 bits 206 The Mean Network Round Trip Delay is the mean value of the RTP-to- 207 RTP interface round trip delay over the measurement period, 208 expressed in units of 1/65536 seconds. This value is typically 209 determined using RTCP SR/RR (See RFC 3550 section 6.4.1). 211 If only one measurement of Round Trip Delay is available for the 212 timespan of the report (i.e.,the measurement period) (whether 213 Interval or Cumulative), this single value SHOULD be reported as 214 the mean value. 216 If the measurement is unavailable, the value of this field with 217 all bits set to 1 MUST be reported. 219 Min Network Round Trip Delay: 32 bits 221 The Min Network Round Trip Delay is the minimum value of the RTP- 222 to-RTP interface round trip delay over the measurement period, 223 expressed in units of 1/65536 seconds. This value is typically 224 determined using RTCP SR/RR. 226 If only one measurement of Round Trip Delay is available for the 227 timespan of the report (i.e.,the measurement period) (whether 228 Interval or Cumulative), this single value SHOULD be reported as 229 the minimum value. 231 If the measurement is unavailable, the value of this field with 232 all bits set to 1 MUST be reported. 234 Max Network Round Trip Delay: 32 bits 236 The Max Network Round Trip Delay is the maximum value of the RTP- 237 to-RTP interface round trip delay over the measurement period, 238 expressed in units of 1/65536 seconds. This value is typically 239 determined using RTCP SR/RR. 241 If only one measurement of Round Trip Delay is available for the 242 timespan of the report (i.e.,the measurement period) (whether 243 Interval or Cumulative), this single value SHOULD be reported as 244 the maximum value. 246 If the measurement is unavailable, the value of this field with 247 all bits set to 1 MUST be reported. 249 End System Delay: 64 bits 251 The End System Delay is the internal round trip delay within the 252 reporting endpoint, calculated using the nominal value of the 253 jitter buffer delay plus the accumulation/encoding and decoding/ 254 playout delay associated with the codec being used. The value of 255 this field is represented using a 64-bit NTP-format timestamp as 256 defined in [RFC5905], which is 64-bit unsigned fixed-point number 257 with the integer part in the first 32 bits and the fractional part 258 in the last 32 bits. 260 If the measurement is unavailable, the value of this field with 261 all bits set to 1 MUST be reported. 263 4. SDP Signaling 265 [RFC3611] defines the use of SDP (Session Description Protocol) 266 [RFC4566] for signaling the use of XR blocks. XR blocks MAY be used 267 without prior signaling. 269 This section augments the SDP [RFC4566] attribute "rtcp-xr" defined 270 in [RFC3611] by providing an additional value of "xr-format" to 271 signal the use of the report block defined in this document. 273 rtcp-xr-attrib = "a=" "rtcp-xr" ":" [xr-format *(SP xr-format)] CRLF 275 (defined in [RFC3611]) 277 xr-format =/ xr-delay-block 279 xr-delay-block ="delay" 281 5. IANA Considerations 283 New block types for RTCP XR are subject to IANA registration. For 284 general guidelines on IANA considerations for RTCP XR, refer to 285 [RFC3611]. 287 5.1. New RTCP XR Block Type value 289 This document assigns the block type value NDEL in the IANA "RTCP XR 290 Block Type Registry" to the "Delay Metrics Block". 292 [Note to RFC Editor: please replace NDEL with the IANA provided RTCP 293 XR block type for this block.] 295 5.2. New RTCP XR SDP Parameter 297 This document also registers a new parameter "delay" in the "RTCP XR 298 SDP Parameters Registry". 300 5.3. Contact information for registrations 302 The contact information for the registrations is: 304 Qin Wu (sunseawq@huawei.com) 306 101 Software Avenue, Yuhua District 307 Nanjing, Jiangsu 210012 308 China 310 6. Security Considerations 312 It is believed that this proposed RTCP XR report block introduces no 313 new security considerations beyond those described in [RFC3611]. 314 This block does not provide per-packet statistics so the risk to 315 confidentiality documented in Section 7, paragraph 3 of [RFC3611] 316 does not apply. 318 7. Contributors 320 Geoff Hunt wrote the initial version of this document. 322 8. Acknowledgments 324 The authors gratefully acknowledge the comments and contributions 325 made by Bruce Adams, Philip Arden, Amit Arora, Bob Biskner, Kevin 326 Connor, Claus Dahm, Randy Ethier, Roni Even, Jim Frauenthal, Albert 327 Higashi, Tom Hock, Shane Holthaus, Paul Jones, Rajesh Kumar, Keith 328 Lantz, Mohamed Mostafa, Amy Pendleton, Colin Perkins, Mike Ramalho, 329 Ravi Raviraj, Albrecht Schwarz, Tom Taylor, and Hideaki Yamada,Jing 330 Zhao,Kevin Gross, Colin Perkins, Charles Eckel, Glen Zorn,Shida 331 Schubert. 333 9. References 335 9.1. Normative References 337 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 338 Requirement Levels", March 1997. 340 [RFC3550] Schulzrinne, H., "RTP: A Transport Protocol for Real-Time 341 Applications", RFC 3550, July 2003. 343 [RFC3611] Friedman, T., Caceres, R., and A. Clark, "RTP Control 344 Protocol Extended Reports (RTCP XR)", November 2003. 346 [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session 347 Description Protocol", July 2006. 349 [RFC5905] Mills, D., Martin, J., Burbank, J., and W. Kasch, "Network 350 Time Protocol Version 4: Protocol and Algorithms 351 Specification", RFC 5905, June 2010. 353 9.2. Informative References 355 [MEASI] Hunt, G., "Measurement Identity and information Reporting 356 using SDES item and XR Block", 357 ID draft-ietf-xrblock-rtcp-xr-meas-identity-09, July 2012. 359 [MONARCH] Hunt, G., "Monitoring Architectures for RTP", 360 ID draft-ietf-avtcore-monarch-18, August 2012. 362 [RFC6390] Clark, A. and B. Claise, "Framework for Performance Metric 363 Development", RFC 6390, October 2011. 365 Appendix A. Change Log 367 Note to the RFC-Editor: please remove this section prior to 368 publication as an RFC. 370 A.1. draft-ietf-xrblock-rtcp-xr-delay-08 372 The following are the major changes to previous version : 374 o Move Geoff Hunt from author list to Contributors section based on 375 his suggestion. 377 A.2. draft-ietf-xrblock-rtcp-xr-delay-07 379 The following are the major changes to previous version : 381 o Editorial changes. 383 o Reference updates. 385 A.3. draft-ietf-xrblock-rtcp-xr-delay-06 387 The following are the major changes to previous version : 389 o Editorial changes. 391 A.4. draft-ietf-xrblock-rtcp-xr-delay-05 393 The following are the major changes to previous version : 395 o One typo fixed. 397 A.5. draft-ietf-xrblock-rtcp-xr-delay-04 399 The following are the major changes to previous version : 401 o Revise the definition of sampled metric to get alignment with 402 MONARCH. 404 o Clarify sending the metric block in the same RTCP compound packet 405 as the measurement information block. 407 A.6. draft-ietf-xrblock-rtcp-xr-delay-03 409 The following are the major changes to previous version : 411 o Allocate 64 bit for end system delay and represent it using 64 bit 412 NTP-Timestamp. 414 o Other editorial changes. 416 A.7. draft-ietf-xrblock-rtcp-xr-delay-02 418 The following are the major changes to previous version : 420 o Allocate 32bits for each metrics and change unit for each metric 421 from ms to 1/65536 seconds. 423 A.8. draft-ietf-xrblock-rtcp-xr-delay-01 425 The following are the major changes to previous version : 427 o Updated references. 429 o Allocate one more bit for Interval metric flag to indicate sampled 430 metric can be used. 432 o add a few clarification text for failure mode. 434 A.9. draft-ietf-xrblock-rtcp-xr-delay-00 436 The following are the major changes to previous version : 438 o Changed BNF for SDP following Christian Groves' and Tom Taylor's 439 comments (4th and 5th May 2009). 441 o Updated references. 443 Authors' Addresses 445 Alan Clark 446 Telchemy Incorporated 447 2905 Premiere Parkway, Suite 280 448 Duluth, GA 30097 449 USA 451 Email: alan.d.clark@telchemy.com 453 Kevin Gross 454 AVA Networks 456 Email: kevin.gross@avanw.com 458 Qin Wu 459 Huawei 460 101 Software Avenue, Yuhua District 461 Nanjing, Jiangsu 210012 462 China 464 Email: sunseawq@huawei.com