idnits 2.17.1 draft-ietf-avt-rtcp-xr-delay-00.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- ** It looks like you're using RFC 3978 boilerplate. You should update this to the boilerplate described in the IETF Trust License Policy document (see https://trustee.ietf.org/license-info), which is required now. -- Found old boilerplate from RFC 3978, Section 5.1 on line 16. -- Found old boilerplate from RFC 3978, Section 5.5, updated by RFC 4748 on line 341. -- Found old boilerplate from RFC 3979, Section 5, paragraph 1 on line 352. -- Found old boilerplate from RFC 3979, Section 5, paragraph 2 on line 359. -- Found old boilerplate from RFC 3979, Section 5, paragraph 3 on line 365. 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 Copyright Line does not match the current year == The document seems to lack the recommended RFC 2119 boilerplate, even if it appears to use RFC 2119 keywords. (The document does seem to have the reference to RFC 2119 which the ID-Checklist requires). -- The document seems to lack a disclaimer for pre-RFC5378 work, but may have content which was first submitted before 10 November 2008. If you have contacted all the original authors and they are all willing to grant the BCP78 rights to the IETF Trust, then this is fine, and you can ignore this comment. If not, you may need to add the pre-RFC5378 disclaimer. (See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- The document date (October 25, 2008) is 5661 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: 'RFC2119' is defined on line 285, but no explicit reference was found in the text -- No information found for draft-ietf-avt-rtcp-xr-measid - is the name correct? -- Possible downref: Normative reference to a draft: ref. 'MEASIDENT' ** Obsolete normative reference: RFC 4566 (Obsoleted by RFC 8866) == Outdated reference: A later version (-12) exists of draft-ietf-pmol-metrics-framework-00 Summary: 2 errors (**), 0 flaws (~~), 4 warnings (==), 9 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Audio/Video Transport Working G. Hunt 3 Group BT 4 Internet-Draft A. Clark 5 Intended status: Standards Track Telchemy 6 Expires: April 28, 2009 October 25, 2008 8 RTCP XR Report Block for Delay metric Reporting 9 draft-ietf-avt-rtcp-xr-delay-00.txt 11 Status of this Memo 13 By submitting this Internet-Draft, each author represents that any 14 applicable patent or other IPR claims of which he or she is aware 15 have been or will be disclosed, and any of which he or she becomes 16 aware will be disclosed, in accordance with Section 6 of BCP 79. 18 Internet-Drafts are working documents of the Internet Engineering 19 Task Force (IETF), its areas, and its working groups. Note that 20 other groups may also distribute working documents as Internet- 21 Drafts. 23 Internet-Drafts are draft documents valid for a maximum of six months 24 and may be updated, replaced, or obsoleted by other documents at any 25 time. It is inappropriate to use Internet-Drafts as reference 26 material or to cite them other than as "work in progress." 28 The list of current Internet-Drafts can be accessed at 29 http://www.ietf.org/ietf/1id-abstracts.txt. 31 The list of Internet-Draft Shadow Directories can be accessed at 32 http://www.ietf.org/shadow.html. 34 This Internet-Draft will expire on April 28, 2009. 36 Abstract 38 This document defines an RTCP XR Report Block that allows the 39 reporting of Delay metrics for use in a range of RTP applications. 41 Table of Contents 43 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 44 1.1. Delay Report Block . . . . . . . . . . . . . . . . . . . . 3 45 1.2. RTCP and RTCP XR Reports . . . . . . . . . . . . . . . . . 3 46 1.3. Performance Metrics Framework . . . . . . . . . . . . . . 3 47 1.4. Applicability . . . . . . . . . . . . . . . . . . . . . . 3 48 2. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 4 49 3. Delay Block . . . . . . . . . . . . . . . . . . . . . . . . . 5 50 3.1. Report Block Structure . . . . . . . . . . . . . . . . . . 5 51 3.2. Definition of Fields in Delay Metrics Report Block . . . . 5 52 4. SDP Signaling . . . . . . . . . . . . . . . . . . . . . . . . 8 53 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 54 6. Security Considerations . . . . . . . . . . . . . . . . . . . 10 55 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 11 56 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 12 57 8.1. Normative References . . . . . . . . . . . . . . . . . . . 12 58 8.2. Informative References . . . . . . . . . . . . . . . . . . 12 59 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 13 60 Intellectual Property and Copyright Statements . . . . . . . . . . 14 62 1. Introduction 64 1.1. Delay Report Block 66 This draft defines a new block type to augment those defined in 67 [RFC3611] for use in a range of RTP applications. The new block type 68 supports the reporting of the mean, minimum and maximum values of the 69 network round-trip delay between RTP interfaces in peer RTP end 70 systems as measured, for example, using the RTCP method described in 71 [RFC3550]. It also supports reporting of the component of the round- 72 trip delay internal to the local RTP system. 74 The network metrics belong to the class of packet transport delay 75 metrics defined in [MONARCH] (work in progress). 77 Instances of this Metrics Block refer by tag to the separate 78 auxiliary Measurement Identity block [MEASIDENT] which contains 79 information such as the SSRC of the measured stream, and RTP sequence 80 numbers and time intervals indicating the span of the report. 82 1.2. RTCP and RTCP XR Reports 84 The use of RTCP for reporting is defined in [RFC3550]. [RFC3611] 85 defined an extensible structure for reporting using an RTCP Extended 86 Report (XR). This draft defines a new Extended Report block that 87 MUST be used as defined in [RFC3550] and [RFC3611]. 89 1.3. Performance Metrics Framework 91 The Performance Metrics Framework [PMOLFRAME] provides guidance on 92 the definition and specification of performance metrics. Metrics 93 described in this draft either reference external definitions or 94 define metrics generally in accordance with the guidelines in 95 [PMOLFRAME]. 97 1.4. Applicability 99 This metric is believed to be applicable to all RTP applications. 101 2. Definitions 103 Numeric formats 105 This report block makes use of binary fractions. The terminology 106 used is 108 S X:Y 110 where S indicates a two's complement signed representation, X the 111 number of bits prior to the decimal place and Y the number of bits 112 after the decimal place. 114 Hence 8:8 represents an unsigned number in the range 0.0 to 115 255.996 with a granularity of 0.0039. S7:8 would represent the 116 range -128.000 to +127.996. 0:16 represents a proper binary 117 fraction with range 119 0.0 to 1 - 1/65536 = 0.9999847 121 though note that use of flag values at the top of the numeric 122 range slightly reduces this upper limit. For example, if the 16- 123 bit values 0xfffe and 0xffff are used as flags for "over-range" 124 and "unavailable" conditions, a 0:16 quantity has range 126 0.0 to 1 - 3/65536 = 0.9999542 128 3. Delay Block 130 3.1. Report Block Structure 132 Delay metrics block 133 0 1 2 3 134 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 7 135 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 136 | BT=NDEL |I| tag | resv | block length = 2 | 137 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 138 | Mean Network Round Trip Delay | End System Delay | 139 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 140 | Min Network Round Trip Delay | Max Network Round Trip Delay | 141 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 143 Figure 1: Report Block Structure 145 3.2. Definition of Fields in Delay Metrics Report Block 147 block type (BT): 8 bits 149 A Delay Report Block is identified by the constant NDEL. 151 [Note to RFC Editor: please replace NDEL with the IANA provided RTCP 152 XR block type for this block.] 154 Interval Metric flag (I): 1 bit 156 This field is used to indicate whether the Delay metric block is 157 an Interval or a Cumulative metric block, that is, whether the 158 reported values apply to the most recent measurement interval 159 duration between successive metrics reports (I=1) (the Interval 160 Duration) or to the accumulation period characteristic of 161 cumulative measurements (I=0) (the Cumulative Duration). 162 Numerical values for both these intervals are provided in the 163 Measurement Identifier block referenced by the tag field below. 165 Measurement Identifier association (tag): 3 bits 167 This field is used to identify the Measurement Identifier block 168 [MEASIDENT] which describes this measurement. The relevant 169 Measurement Identifier block has the same tag value as the Delay 170 block. Note that there may be more than one Measurement 171 Identifier block per RTCP packet. 173 Reserved (resv): 4 bits 174 These bits are reserved. They SHOULD be set to zero by senders 175 and MUST be ignored by receivers. 177 block length: 16 bits 179 The length of this report block in 32-bit words, minus one. For 180 the Delay block, the block length is equal to 2. 182 Mean Network Round Trip Delay (ms): 16 bits 184 The Mean Network Round Trip Delay is the mean value of the RTP-to- 185 RTP interface round trip delay in ms over the measurement period, 186 typically determined using RTCP SR/RR. 188 If only one measurement of Round Trip Delay is available for the 189 timespan of the report (whether Interval or Cumulative), this 190 single value should be reported as the mean value. 192 If the measured value exceeds 0xFFFD, the value 0xFFFE SHOULD be 193 reported to indicate an over-range measurement. If the 194 measurement is unavailable, the value 0xFFFF SHOULD be reported. 196 End System Delay (ms): 16 bits 198 The End System Delay is the internal round trip delay within the 199 reporting endpoint, calculated using the nominal value of the 200 jitter buffer delay plus the accumulation/ encoding and decoding / 201 playout delay associated with the codec being used. 203 If the measured or estimated value exceeds 0xFFFD, the value 204 0xFFFE SHOULD be reported to indicate an over-range measurement. 205 If the measurement is unavailable, the value 0xFFFF SHOULD be 206 reported. 208 Min Network Round Trip Delay (ms): 16 bits 210 The Min Network Round Trip Delay is the minimum value of the RTP- 211 to-RTP interface round trip delay in ms over the measurement 212 period, typically determined using RTCP SR/RR. 214 If only one measurement of Round Trip Delay is available for the 215 timespan of the report (whether Interval or Cumulative), this 216 single value should be reported as the minimum value. 218 If the measured value exceeds 0xFFFD, the value 0xFFFE SHOULD be 219 reported to indicate an over-range measurement. If the 220 measurement is unavailable, the value 0xFFFF SHOULD be reported. 222 Max Network Round Trip Delay (ms): 16 bits 224 The Max Network Round Trip Delay is the maximum value of the RTP- 225 to-RTP interface round trip delay in ms over the measurement 226 period, typically determined using RTCP SR/RR. 228 If only one measurement of Round Trip Delay is available for the 229 timespan of the report (whether Interval or Cumulative), this 230 single value should be reported as the maximum value. 232 If the measured value exceeds 0xFFFD, the value 0xFFFE SHOULD be 233 reported to indicate an over-range measurement. If the 234 measurement is unavailable, the value 0xFFFF SHOULD be reported. 236 4. SDP Signaling 238 [RFC3611] defines the use of SDP (Session Description Protocol) 239 [RFC4566] for signaling the use of XR blocks. XR blocks MAY be used 240 without prior signaling. 242 This section augments the SDP [RFC4566] attribute "rtcp-xr" defined 243 in [RFC3611] by providing an additional value of "xr-format" to 244 signal the use of the report block defined in this document. 246 rtcp-xr-attrib = "a=" "rtcp-xr" ":" [xr-format *(SP xr-format)] CRLF 248 (defined in [RFC3611]) 250 xr-format = xr-format / xr-delay-block 252 xr-delay-block = "xr-delay" 254 5. IANA Considerations 256 This document creates a new block type within the IANA "RTCP XR Block 257 Type Registry" called the Delay Block, and a new parameter xr-delay 258 within the "RTCP XR SDP Parameters Registry". 260 6. Security Considerations 262 It is believed that this proposed RTCP XR report block introduces no 263 new security considerations beyond those described in [RFC3611]. 264 This block does not provide per-packet statistics so the risk to 265 confidentiality documented in Section 7, paragraph 3 of [RFC3611] 266 does not apply. 268 7. Contributors 270 The authors gratefully acknowledge the comments and contributions 271 made by Bruce Adams, Philip Arden, Amit Arora, Bob Biskner, Kevin 272 Connor, Claus Dahm, Randy Ethier, Roni Even, Jim Frauenthal, Albert 273 Higashi, Tom Hock, Shane Holthaus, Paul Jones, Rajesh Kumar, Keith 274 Lantz, Mohamed Mostafa, Amy Pendleton, Colin Perkins, Mike Ramalho, 275 Ravi Raviraj, Albrecht Schwarz, Tom Taylor, and Hideaki Yamada. 277 8. References 279 8.1. Normative References 281 [MEASIDENT] 282 Hunt, G., "RTCP XR Measurement Identifier Block", 283 ID draft-ietf-avt-rtcp-xr-measid-00, August 2008. 285 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 286 Requirement Levels", RFC 2119, BCP 14, March 1997. 288 [RFC3550] Schulzrinne, H., "RTP: A Transport Protocol for Real-Time 289 Applications", RFC 3550, July 2003. 291 [RFC3611] Friedman, T., "RTP Control Protocol Extended Reports (RTCP 292 XR)", RFC 3611, November 2003. 294 [RFC4566] Handley, M., "SDP: Session Description Protocol", 295 RFC 4566, July 2006. 297 8.2. Informative References 299 [MONARCH] Hunt, G., "Monitoring Architectures for RTP", 300 ID draft-hunt-avt-monarch-01, August 2008. 302 [PMOLFRAME] 303 Clark, A., "Framework for Performance Metric Development", 304 ID draft-ietf-pmol-metrics-framework-00, July 2008. 306 Authors' Addresses 308 Geoff Hunt 309 BT 310 Orion 1 PP9 311 Adastral Park 312 Martlesham Heath 313 Ipswich, Suffolk IP4 2TH 314 United Kingdom 316 Phone: +44 1473 608325 317 Email: geoff.hunt@bt.com 319 Alan Clark 320 Telchemy Incorporated 321 2905 Premiere Parkway, Suite 280 322 Duluth, GA 30097 323 USA 325 Email: alan.d.clark@telchemy.com 327 Full Copyright Statement 329 Copyright (C) The IETF Trust (2008). 331 This document is subject to the rights, licenses and restrictions 332 contained in BCP 78, and except as set forth therein, the authors 333 retain all their rights. 335 This document and the information contained herein are provided on an 336 "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS 337 OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND 338 THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS 339 OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF 340 THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED 341 WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 343 Intellectual Property 345 The IETF takes no position regarding the validity or scope of any 346 Intellectual Property Rights or other rights that might be claimed to 347 pertain to the implementation or use of the technology described in 348 this document or the extent to which any license under such rights 349 might or might not be available; nor does it represent that it has 350 made any independent effort to identify any such rights. Information 351 on the procedures with respect to rights in RFC documents can be 352 found in BCP 78 and BCP 79. 354 Copies of IPR disclosures made to the IETF Secretariat and any 355 assurances of licenses to be made available, or the result of an 356 attempt made to obtain a general license or permission for the use of 357 such proprietary rights by implementers or users of this 358 specification can be obtained from the IETF on-line IPR repository at 359 http://www.ietf.org/ipr. 361 The IETF invites any interested party to bring to its attention any 362 copyrights, patents or patent applications, or other proprietary 363 rights that may cover technology that may be required to implement 364 this standard. Please address the information to the IETF at 365 ietf-ipr@ietf.org.