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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group M. Bagnulo 3 Internet-Draft UC3M 4 Intended status: Best Current Practice B. Claise 5 Expires: April 13, 2017 Cisco Systems, Inc. 6 P. Eardley 7 BT 8 A. Morton 9 AT&T Labs 10 A. Akhter 11 Consultant 12 October 10, 2016 14 Registry for Performance Metrics 15 draft-ietf-ippm-metric-registry-08 17 Abstract 19 This document defines the format for the Performance Metrics registry 20 and defines the IANA Registry for Performance Metrics. This document 21 also gives a set of guidelines for Registered Performance Metric 22 requesters and reviewers. 24 Status of This Memo 26 This Internet-Draft is submitted in full conformance with the 27 provisions of BCP 78 and BCP 79. 29 Internet-Drafts are working documents of the Internet Engineering 30 Task Force (IETF). Note that other groups may also distribute 31 working documents as Internet-Drafts. The list of current Internet- 32 Drafts is at http://datatracker.ietf.org/drafts/current/. 34 Internet-Drafts are draft documents valid for a maximum of six months 35 and may be updated, replaced, or obsoleted by other documents at any 36 time. It is inappropriate to use Internet-Drafts as reference 37 material or to cite them other than as "work in progress." 39 This Internet-Draft will expire on April 13, 2017. 41 Copyright Notice 43 Copyright (c) 2016 IETF Trust and the persons identified as the 44 document authors. All rights reserved. 46 This document is subject to BCP 78 and the IETF Trust's Legal 47 Provisions Relating to IETF Documents 48 (http://trustee.ietf.org/license-info) in effect on the date of 49 publication of this document. Please review these documents 50 carefully, as they describe your rights and restrictions with respect 51 to this document. Code Components extracted from this document must 52 include Simplified BSD License text as described in Section 4.e of 53 the Trust Legal Provisions and are provided without warranty as 54 described in the Simplified BSD License. 56 Table of Contents 58 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 59 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 60 3. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 61 4. Motivation for a Performance Metrics Registry . . . . . . . . 7 62 4.1. Interoperability . . . . . . . . . . . . . . . . . . . . 7 63 4.2. Single point of reference for Performance Metrics . . . . 8 64 4.3. Side benefits . . . . . . . . . . . . . . . . . . . . . . 8 65 5. Criteria for Performance Metrics Registration . . . . . . . . 9 66 6. Performance Metric Registry: Prior attempt . . . . . . . . . 9 67 6.1. Why this Attempt Will Succeed . . . . . . . . . . . . . . 10 68 7. Definition of the Performance Metric Registry . . . . . . . . 10 69 7.1. Summary Category . . . . . . . . . . . . . . . . . . . . 12 70 7.1.1. Identifier . . . . . . . . . . . . . . . . . . . . . 12 71 7.1.2. Name . . . . . . . . . . . . . . . . . . . . . . . . 13 72 7.1.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . 15 73 7.1.4. Description . . . . . . . . . . . . . . . . . . . . . 15 74 7.1.5. Reference . . . . . . . . . . . . . . . . . . . . . . 15 75 7.1.6. Change Controller . . . . . . . . . . . . . . . . . . 15 76 7.2. Metric Definition Category . . . . . . . . . . . . . . . 16 77 7.2.1. Reference Definition . . . . . . . . . . . . . . . . 16 78 7.2.2. Fixed Parameters . . . . . . . . . . . . . . . . . . 16 79 7.3. Method of Measurement Category . . . . . . . . . . . . . 17 80 7.3.1. Reference Method . . . . . . . . . . . . . . . . . . 17 81 7.3.2. Packet Stream Generation . . . . . . . . . . . . . . 17 82 7.3.3. Traffic Filter . . . . . . . . . . . . . . . . . . . 18 83 7.3.4. Sampling Distribution . . . . . . . . . . . . . . . . 18 84 7.3.5. Run-time Parameters . . . . . . . . . . . . . . . . . 19 85 7.3.6. Role . . . . . . . . . . . . . . . . . . . . . . . . 19 86 7.4. Output Category . . . . . . . . . . . . . . . . . . . . . 20 87 7.4.1. Type . . . . . . . . . . . . . . . . . . . . . . . . 20 88 7.4.2. Reference Definition . . . . . . . . . . . . . . . . 20 89 7.4.3. Metric Units . . . . . . . . . . . . . . . . . . . . 20 90 7.5. Administrative information . . . . . . . . . . . . . . . 20 91 7.5.1. Status . . . . . . . . . . . . . . . . . . . . . . . 20 92 7.5.2. Requester . . . . . . . . . . . . . . . . . . . . . . 21 93 7.5.3. Revision . . . . . . . . . . . . . . . . . . . . . . 21 94 7.5.4. Revision Date . . . . . . . . . . . . . . . . . . . . 21 95 7.6. Comments and Remarks . . . . . . . . . . . . . . . . . . 21 96 8. The Life-Cycle of Registered Performance Metrics . . . . . . 21 97 8.1. Adding new Performance Metrics to the Performance Metrics 98 Registry . . . . . . . . . . . . . . . . . . . . . . . . 21 99 8.2. Revising Registered Performance Metrics . . . . . . . . . 22 100 8.3. Deprecating Registered Performance Metrics . . . . . . . 24 101 9. Security considerations . . . . . . . . . . . . . . . . . . . 24 102 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 24 103 11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 26 104 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 26 105 12.1. Normative References . . . . . . . . . . . . . . . . . . 26 106 12.2. Informative References . . . . . . . . . . . . . . . . . 27 107 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 29 109 1. Introduction 111 The IETF specifies and uses Performance Metrics of protocols and 112 applications transported over its protocols. Performance metrics are 113 such an important part of the operations of IETF protocols that 114 [RFC6390] specifies guidelines for their development. 116 The definition and use of Performance Metrics in the IETF happens in 117 various working groups (WG), most notably: 119 The "IP Performance Metrics" (IPPM) WG is the WG primarily 120 focusing on Performance Metrics definition at the IETF. 122 The "Metric Blocks for use with RTCP's Extended Report Framework" 123 (XRBLOCK) WG recently specified many Performance Metrics related 124 to "RTP Control Protocol Extended Reports (RTCP XR)" [RFC3611], 125 which establishes a framework to allow new information to be 126 conveyed in RTCP, supplementing the original report blocks defined 127 in "RTP: A Transport Protocol for Real-Time Applications", 128 [RFC3550]. 130 The "Benchmarking Methodology" WG (BMWG) defined many Performance 131 Metrics for use in laboratory benchmarking of inter-networking 132 technologies. 134 The "IP Flow Information eXport" (IPFIX) concluded WG specified an 135 IANA process for new Information Elements. Some Performance 136 Metrics related Information Elements are proposed on regular 137 basis. 139 The "Performance Metrics for Other Layers" (PMOL) concluded WG, 140 defined some Performance Metrics related to Session Initiation 141 Protocol (SIP) voice quality [RFC6035]. 143 It is expected that more Performance Metrics will be defined in the 144 future, not only IP-based metrics, but also metrics which are 145 protocol-specific and application-specific. 147 However, despite the importance of Performance Metrics, there are two 148 related problems for the industry. First, how to ensure that when 149 one party requests another party to measure (or report or in some way 150 act on) a particular Performance Metric, then both parties have 151 exactly the same understanding of what Performance Metric is being 152 referred to. Second, how to discover which Performance Metrics have 153 been specified, so as to avoid developing new Performance Metric that 154 is very similar, but not quite inter-operable. The problems can be 155 addressed by creating a registry of performance metrics. The usual 156 way in which IETF organizes namespaces is with Internet Assigned 157 Numbers Authority (IANA) registries, and there is currently no 158 Performance Metrics Registry maintained by the IANA. 160 This document therefore requests that IANA create and maintain a 161 Performance Metrics Registry, according to the maintenance procedures 162 and the Performance Metrics Registry format defined in this memo. 163 Although the Registry format is primarily for use by IANA, any other 164 organization that wishes to create a Performance Metrics Registry MAY 165 use the same format for their purposes. The authors make no 166 guarantee of the format's applicability to any possible set of 167 Performance Metrics envisaged by other organizations, but encourage 168 others to apply it. In the remainder of this document, unless we 169 explicitly say so, we will refer to the IANA-maintained Performance 170 Metrics Registry as simply the Performance Metrics Registry. 172 2. Terminology 174 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 175 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and 176 "OPTIONAL" in this document are to be interpreted as described in 177 [RFC2119]. 179 Performance Metric: A Performance Metric is a quantitative measure 180 of performance, targeted to an IETF-specified protocol or targeted 181 to an application transported over an IETF-specified protocol. 182 Examples of Performance Metrics are the FTP response time for a 183 complete file download, the DNS response time to resolve the IP 184 address, a database logging time, etc. This definition is 185 consistent with the definition of metric in [RFC2330] and broader 186 than the definition of performance metric in [RFC6390]. 188 Registered Performance Metric: A Registered Performance Metric is a 189 Performance Metric expressed as an entry in the Performance Metric 190 Registry, administered by IANA. Such a performance metric has met 191 all the registry review criteria defined in this document in order 192 to included in the registry. 194 Performance Metrics Registry: The IANA registry containing 195 Registered Performance Metrics. 197 Proprietary Registry: A set of metrics that are registered in a 198 proprietary registry, as opposed to Performance Metrics Registry. 200 Performance Metrics Experts: The Performance Metrics Experts is a 201 group of designated experts [RFC5226] selected by the IESG to 202 validate the Performance Metrics before updating the Performance 203 Metrics Registry. The Performance Metrics Experts work closely 204 with IANA. 206 Parameter: An input factor defined as a variable in the definition 207 of a Performance Metric. A numerical or other specified factor 208 forming one of a set that defines a metric or sets the conditions 209 of its operation. All Parameters must be known to measure using a 210 metric and interpret the results. There are two types of 211 Parameters, Fixed and Run-time parameters. For the Fixed 212 Parameters, the value of the variable is specified in the 213 Performance Metrics Registry entry and different Fixed Parameter 214 values results in different Registered Performance Metrics. For 215 the Run-time Parameters, the value of the variable is defined when 216 the metric measurement method is executed and a given Registered 217 Performance Metric supports multiple values for the parameter. 218 Although Run-time Parameters do not change the fundamental nature 219 of the Performance Metric's definition, some have substantial 220 influence on the network property being assessed and 221 interpretation of the results. 223 Note: Consider the case of packet loss in the following two 224 Active Measurement Method cases. The first case is packet loss 225 as background loss where the Run-time Parameter set includes a 226 very sparse Poisson stream, and only characterizes the times 227 when packets were lost. Actual user streams likely see much 228 higher loss at these times, due to tail drop or radio errors. 229 The second case is packet loss as inverse of throughput where 230 the Run-time Parameter set includes a very dense, bursty 231 stream, and characterizes the loss experienced by a stream that 232 approximates a user stream. These are both "loss metrics", but 233 the difference in interpretation of the results is highly 234 dependent on the Run-time Parameters (at least), to the extreme 235 where we are actually using loss to infer its compliment: 236 delivered throughput. 238 Active Measurement Method: Methods of Measurement conducted on 239 traffic which serves only the purpose of measurement and is 240 generated for that reason alone, and whose traffic characteristics 241 are known a priori. The complete definition of Active Methods is 242 specified in section 3.4 of[RFC7799]. Examples of Active 243 Measurement Methods are the measurement methods for the One way 244 delay metric defined in [RFC7679] and the one for round trip delay 245 defined in [RFC2681]. 247 Passive Measurement Method: Methods of Measurement conducted on 248 network traffic, generated either from the end users or from 249 network elements that would exist regardless whether the 250 measurement was being conducted or not. The complete definition 251 of Passive Methods is specified in section 3.6 of [RFC7799]. One 252 characteristic of Passive Measurement Methods is that sensitive 253 information may be observed, and as a consequence, stored in the 254 measurement system. 256 Hybrid Measurement Method: Hybrid Methods are Methods of Measurement 257 that use a combination of Active Methods and Passive Methods, to 258 assess Active Metrics, Passive Metrics, or new metrics derived 259 from the a priori knowledge and observations of the stream of 260 interest. The complete definition of Hybrid Methods is specified 261 in section 3.8 of [RFC7799]. 263 3. Scope 265 This document is meant mainly for two different audiences. For those 266 defining new Registered Performance Metrics, it provides 267 specifications and best practices to be used in deciding which 268 Registered Performance Metrics are useful for a measurement study, 269 instructions for writing the text for each column of the Registered 270 Performance Metrics, and information on the supporting documentation 271 required for the new Performance Metrics Registry entry (up to and 272 including the publication of one or more RFCs or I-Ds describing it). 273 For the appointed Performance Metrics Experts and for IANA personnel 274 administering the new IANA Performance Metric Registry, it defines a 275 set of acceptance criteria against which these proposed Registered 276 Performance Metrics should be evaluated. In addition, this document 277 may be useful for other organization who are defining a Performance 278 Metric registry of its own, who can rely on the Performance Metric 279 registry defined in this document. 281 This Performance Metric Registry is applicable to Performance Metrics 282 issued from Active Measurement, Passive Measurement, and any other 283 form of Performance Metric. This registry is designed to encompass 284 Performance Metrics developed throughout the IETF and especially for 285 the technologies specified in the following working groups: IPPM, 286 XRBLOCK, IPFIX, and BMWG. This document analyzes an prior attempt to 287 set up a Performance Metric Registry, and the reasons why this design 288 was inadequate [RFC6248]. Finally, this document gives a set of 289 guidelines for requesters and expert reviewers of candidate 290 Registered Performance Metrics. 292 This document makes no attempt to populate the Performance Metrics 293 Registry with initial entries. It does provides a few examples that 294 are merely illustrations and should not be included in the registry 295 at this point in time. 297 Based on [RFC5226] Section 4.3, this document is processed as Best 298 Current Practice (BCP) [RFC2026]. 300 4. Motivation for a Performance Metrics Registry 302 In this section, we detail several motivations for the Performance 303 Metric Registry. 305 4.1. Interoperability 307 As any IETF registry, the primary use for a registry is to manage a 308 namespace for its use within one or more protocols. In the 309 particular case of the Performance Metric Registry, there are two 310 types of protocols that will use the Performance Metrics in the 311 Performance Metrics Registry during their operation (by referring to 312 the Index values): 314 o Control protocol: this type of protocols is used to allow one 315 entity to request another entity to perform a measurement using a 316 specific metric defined by the Performance Metrics Registry. One 317 particular example is the LMAP framework [RFC7594]. Using the 318 LMAP terminology, the Performance Metrics Registry is used in the 319 LMAP Control protocol to allow a Controller to request a 320 measurement task to one or more Measurement Agents. In order to 321 enable this use case, the entries of the Performance Metric 322 Registry must be well enough defined to allow a Measurement Agent 323 implementation to trigger a specific measurement task upon the 324 reception of a control protocol message. This requirement heavily 325 constrains the type of entries that are acceptable for the 326 Performance Metric Registry. 328 o Report protocol: This type of protocols is used to allow an entity 329 to report measurement results to another entity. By referencing 330 to a specific Performance Metric Registry, it is possible to 331 properly characterize the measurement result data being reported. 332 Using the LMAP terminology, the Performance Metrics Registry is 333 used in the Report protocol to allow a Measurement Agent to report 334 measurement results to a Collector. 336 It should be noted that the LMAP framework explicitly allows for 337 using not only the IANA-maintained Performance Metrics Registry but 338 also other registries containing Performance Metrics, either defined 339 by other organizations or private ones. However, others who are 340 creating Registries to be used in the context of an LMAP framework 341 are encouraged to use the Registry format defined in this document, 342 because this makes it easier for developers of LMAP Measurement 343 Agents (MAs) to programmatically use information found in those other 344 Registries' entries. 346 4.2. Single point of reference for Performance Metrics 348 A Performance Metrics Registry serves as a single point of reference 349 for Performance Metrics defined in different working groups in the 350 IETF. As we mentioned earlier, there are several WGs that define 351 Performance Metrics in the IETF and it is hard to keep track of all 352 them. This results in multiple definitions of similar Performance 353 Metrics that attempt to measure the same phenomena but in slightly 354 different (and incompatible) ways. Having a registry would allow 355 both the IETF community and external people to have a single list of 356 relevant Performance Metrics defined by the IETF (and others, where 357 appropriate). The single list is also an essential aspect of 358 communication about Performance Metrics, where different entities 359 that request measurements, execute measurements, and report the 360 results can benefit from a common understanding of the referenced 361 Performance Metric. 363 4.3. Side benefits 365 There are a couple of side benefits of having such a registry. 366 First, the Performance Metrics Registry could serve as an inventory 367 of useful and used Performance Metrics, that are normally supported 368 by different implementations of measurement agents. Second, the 369 results of measurements using the Performance Metrics would be 370 comparable even if they are performed by different implementations 371 and in different networks, as the Performance Metric is properly 372 defined. BCP 176 [RFC6576] examines whether the results produced by 373 independent implementations are equivalent in the context of 374 evaluating the completeness and clarity of metric specifications. 375 This BCP defines the standards track advancement testing for (active) 376 IPPM metrics, and the same process will likely suffice to determine 377 whether Registered Performance Metrics are sufficiently well 378 specified to result in comparable (or equivalent) results. 379 Registered Performance Metrics which have undergone such testing 380 SHOULD be noted, with a reference to the test results. 382 5. Criteria for Performance Metrics Registration 384 It is neither possible nor desirable to populate the Performance 385 Metrics Registry with all combinations of Parameters of all 386 Performance Metrics. The Registered Performance Metrics should be: 388 1. interpretable by the user. 390 2. implementable by the software designer, 392 3. deployable by network operators, 394 4. accurate, for interoperability and deployment across vendors, 396 5. Operationally useful, so that it has significant industry 397 interest and/or has seen deployment, 399 6. Sufficiently tightly defined, so that different values for the 400 Run-time Parameters does not change the fundamental nature of the 401 measurement, nor change the practicality of its implementation. 403 In essence, there needs to be evidence that a candidate Registered 404 Performance Metric has significant industry interest, or has seen 405 deployment, and there is agreement that the candidate Registered 406 Performance Metric serves its intended purpose. 408 6. Performance Metric Registry: Prior attempt 410 There was a previous attempt to define a metric registry RFC 4148 411 [RFC4148]. However, it was obsoleted by RFC 6248 [RFC6248] because 412 it was "found to be insufficiently detailed to uniquely identify IPPM 413 metrics... [there was too much] variability possible when 414 characterizing a metric exactly" which led to the RFC4148 registry 415 having "very few users, if any". 417 A couple of interesting additional quotes from RFC 6248 might help 418 understand the issues related to that registry. 420 1. "It is not believed to be feasible or even useful to register 421 every possible combination of Type P, metric parameters, and 422 Stream parameters using the current structure of the IPPM Metrics 423 Registry." 425 2. "The registry structure has been found to be insufficiently 426 detailed to uniquely identify IPPM metrics." 428 3. "Despite apparent efforts to find current or even future users, 429 no one responded to the call for interest in the RFC 4148 430 registry during the second half of 2010." 432 The current approach learns from this by tightly defining each 433 Registered Performance Metric with only a few variable (Run-time) 434 Parameters to be specified by the measurement designer, if any. The 435 idea is that entries in the Performance Metrics Registry stem from 436 different measurement methods which require input (Run-time) 437 parameters to set factors like source and destination addresses 438 (which do not change the fundamental nature of the measurement). The 439 downside of this approach is that it could result in a large number 440 of entries in the Performance Metrics Registry. There is agreement 441 that less is more in this context - it is better to have a reduced 442 set of useful metrics rather than a large set of metrics, some with 443 with questionable usefulness. 445 6.1. Why this Attempt Will Succeed 447 As mentioned in the previous section, one of the main issues with the 448 previous registry was that the metrics contained in the registry were 449 too generic to be useful. This document specifies stricter criteria 450 for performance metric registration (see section 6), and imposes a 451 group of Performance Metrics Experts that will provide guidelines to 452 assess if a Performance Metric is properly specified. 454 Another key difference between this attempt and the previous one is 455 that in this case there is at least one clear user for the 456 Performance Metrics Registry: the LMAP framework and protocol. 457 Because the LMAP protocol will use the Performance Metrics Registry 458 values in its operation, this actually helps to determine if a metric 459 is properly defined. In particular, since we expect that the LMAP 460 control protocol will enable a controller to request a measurement 461 agent to perform a measurement using a given metric by embedding the 462 Performance Metric Registry value in the protocol, a metric is 463 properly specified if it is defined well-enough so that it is 464 possible (and practical) to implement the metric in the measurement 465 agent. This was the failure of the previous attempt: a registry 466 entry with an undefined Type-P (section 13 of RFC 2330 [RFC2330]) 467 allows implementation to be ambiguous. 469 7. Definition of the Performance Metric Registry 471 This Performance Metric Registry is applicable to Performance Metrics 472 used for Active Measurement, Passive Measurement, and any other form 473 of Performance Metric. Each category of measurement has unique 474 properties, so some of the columns defined below are not applicable 475 for a given metric category. In this case, the column(s) SHOULD be 476 populated with the "NA" value (Non Applicable). However, the "NA" 477 value MUST NOT be used by any metric in the following columns: 478 Identifier, Name, URI, Status, Requester, Revision, Revision Date, 479 Description. In the future, a new category of metrics could require 480 additional columns, and adding new columns is a recognized form of 481 registry extension. The specification defining the new column(s) 482 MUST give guidelines to populate the new column(s) for existing 483 entries (in general). 485 The columns of the Performance Metric Registry are defined below. 486 The columns are grouped into "Categories" to facilitate the use of 487 the registry. Categories are described at the 7.x heading level, and 488 columns are at the 7.x.y heading level. The Figure below illustrates 489 this organization. An entry (row) therefore gives a complete 490 description of a Registered Performance Metric. 492 Each column serves as a check-list item and helps to avoid omissions 493 during registration and expert review. 495 Registry Categories and Columns, shown as 497 Category | 498 ------------------ 499 Column | Column | 501 Summary 502 ---------------------------------------------------------------------- 503 Identifier | Name | URIs | Description | Reference | Change Controller 505 Metric Definition 506 ----------------------------------------- 507 Reference Definition | Fixed Parameters | 509 Method of Measurement 510 --------------------------------------------------------------------- 511 Reference | Packet | Traffic | Sampling | Run-time | Role | 512 Method | Stream | Filter | Distribution | Parameters | | 513 | Generation | 514 Output 515 ----------------------------- 516 | Type | Reference | Units | 517 | | Definition | | 519 Administrative Information 520 ---------------------------------- 521 Status |Request | Rev | Rev.Date | 523 Comments and Remarks 524 -------------------- 526 7.1. Summary Category 528 7.1.1. Identifier 530 A numeric identifier for the Registered Performance Metric. This 531 identifier MUST be unique within the Performance Metric Registry. 533 The Registered Performance Metric unique identifier is a 16-bit 534 integer (range 0 to 65535). 536 The Identifier 0 should be Reserved. The Identifier values from 537 64512 to 65536 are reserved for private use. 539 When adding newly Registered Performance Metrics to the Performance 540 Metric Registry, IANA should assign the lowest available identifier 541 to the next Registered Performance Metric. 543 7.1.2. Name 545 As the name of a Registered Performance Metric is the first thing a 546 potential human implementor will use when determining whether it is 547 suitable for their measurement study, it is important to be as 548 precise and descriptive as possible. In future, users will review 549 the names to determine if the metric they want to measure has already 550 been registered, or if a similar entry is available as a basis for 551 creating a new entry. 553 Names are composed of the following elements, separated by an 554 underscore character "_": 556 MetricType_Method_SubTypeMethod_... Spec_Units_Output 558 o MetricType: a combination of the directional properties and the 559 metric measured, such as: 561 RTDelay 563 OWDelay 565 RTLoss 567 OWLoss 569 OWPDV 571 OWIPDV 573 OWReorder 575 OWDuplic 577 o Method: One of the methods defined in [RFC7799], such as: 579 Active 581 Passive 583 HybridType1 585 HybridType2 587 Spatial 589 o SubTypeMethod: One or more sub-types to further describe the 590 features of the entry, such as: 592 ICMP 594 IP 596 UDP 598 Poisson 600 Periodic 602 o 604 o Spec: RFC that specifies this entry in the form RFCXXXXsecY, such 605 as RFC7799sec3. Note: this is not the Primary Reference 606 specification for the metric; it will be blank until the RFC 607 number is assigned, and would remain blank in private registry 608 entries without an RFC. 610 o Units: The units of measurement for the output, such as: 612 Seconds 614 RatioPercent 616 EventTotal (for unit-less counts) 618 o Output: The type of output resulting from measurement, such as: 620 Singleton 622 Minimum 624 Maximum 626 Median 628 Mean 630 95percentile 632 99percentile 634 An example is: 636 RTDelay_Active_UDP_Poisson_RFCXXXXsecY_Seconds_95th%tile 638 as described in section 4 of [I-D.ietf-ippm-initial-registry]. 640 Note that private registries following the format described here 641 SHOULD use the prefix "Priv_" on any name to avoid unintended 642 conflicts (further considerations are described in section 10). 643 Private registry entries usually have no specifying RFC, thus the 644 Spec: element has no clear interpretation. 646 7.1.3. URIs 648 The URIs column MUST contain a URI [RFC3986] that uniquely identifies 649 the metric. This URI is a URN [RFC2141]. The URI is automatically 650 generated by prepending the prefix urn:ietf:params:ippm:metric: to 651 the metric name. The resulting URI is globally unique. 653 The URIs column MUST contain a second URI which is a URL [RFC3986] 654 and uniquely identifies and locates the metric entry so it is 655 accessible through the Internet. The URL points to a file containing 656 the human-readable information of exactly one registry entry. 657 Ideally, the file will be HTML-formated and contain URLs to 658 referenced sections of HTML-ized RFCs. The separate files for 659 different entries can be more easily edited and re-used when 660 preparing new entries. The exact composition of each metric URL will 661 be determined by IANA and reside on "iana.org", but there will be 662 some overlap with the URN described above. The major sections of 663 [I-D.ietf-ippm-initial-registry] provide an example in HTML form 664 (sections 4 and above). 666 7.1.4. Description 668 A Registered Performance Metric description is a written 669 representation of a particular Performance Metrics Registry entry. 670 It supplements the Registered Performance Metric name to help 671 Performance Metrics Registry users select relevant Registered 672 Performance Metrics. 674 7.1.5. Reference 676 This entry gives the specification containing the candidate registry 677 entry which was reviewed and agreed, if such an RFC or other 678 specification exists. 680 7.1.6. Change Controller 682 This entry names the entity responsible for approving revsions to the 683 regsitry entry, and provides contact information. 685 7.2. Metric Definition Category 687 This category includes columns to prompt all necessary details 688 related to the metric definition, including the RFC reference and 689 values of input factors, called fixed parameters, which are left open 690 in the RFC but have a particular value defined by the performance 691 metric. 693 7.2.1. Reference Definition 695 This entry provides a reference (or references) to the relevant 696 section(s) of the document(s) that define the metric, as well as any 697 supplemental information needed to ensure an unambiguous definition 698 for implementations. The reference needs to be an immutable 699 document, such as an RFC; for other standards bodies, it is likely to 700 be necessary to reference a specific, dated version of a 701 specification. 703 7.2.2. Fixed Parameters 705 Fixed Parameters are Parameters whose value must be specified in the 706 Performance Metrics Registry. The measurement system uses these 707 values. 709 Where referenced metrics supply a list of Parameters as part of their 710 descriptive template, a sub-set of the Parameters will be designated 711 as Fixed Parameters. For example, for active metrics, Fixed 712 Parameters determine most or all of the IPPM Framework convention 713 "packets of Type-P" as described in [RFC2330], such as transport 714 protocol, payload length, TTL, etc. An example for passive metrics 715 is for RTP packet loss calculation that relies on the validation of a 716 packet as RTP which is a multi-packet validation controlled by 717 MIN_SEQUENTIAL as defined by [RFC3550]. Varying MIN_SEQUENTIAL 718 values can alter the loss report and this value could be set as a 719 Fixed Parameter. 721 Parameters MUST have well defined names. For human readers, the 722 hanging indent style is preferred, and the names and definitions that 723 do not appear in the Reference Method Specification MUST appear in 724 this column. 726 Parameters MUST have a well-specified data format. 728 A Parameter which is a Fixed Parameter for one Performance Metrics 729 Registry entry may be designated as a Run-time Parameter for another 730 Performance Metrics Registry entry. 732 7.3. Method of Measurement Category 734 This category includes columns for references to relevant sections of 735 the RFC(s) and any supplemental information needed to ensure an 736 unambiguous method for implementations. 738 7.3.1. Reference Method 740 This entry provides references to relevant sections of the RFC(s) 741 describing the method of measurement, as well as any supplemental 742 information needed to ensure unambiguous interpretation for 743 implementations referring to the RFC text. 745 Specifically, this section should include pointers to pseudocode or 746 actual code that could be used for an unambigious implementation. 748 7.3.2. Packet Stream Generation 750 This column applies to Performance Metrics that generate traffic for 751 a part of their Measurement Method purposes including but not 752 necessarily limited to Active metrics. The generated traffic is 753 referred as stream and this columns describe its characteristics. 755 Each entry for this column contains the following information: 757 o Value: The name of the packet stream scheduling discipline 759 o Reference: the specification where the stream is defined 761 The packet generation stream may require parameters such as the the 762 average packet rate and distribution truncation value for streams 763 with Poisson-distributed inter-packet sending times. In case such 764 parameters are needed, they should be included either in the Fixed 765 parameter column or in the run time parameter column, depending on 766 wether they will be fixed or will be an input for the metric. 768 The simplest example of stream specification is Singleton scheduling 769 (see [RFC2330]), where a single atomic measurement is conducted. 770 Each atomic measurement could consist of sending a single packet 771 (such as a DNS request) or sending several packets (for example, to 772 request a webpage). Other streams support a series of atomic 773 measurements in a "sample", with a schedule defining the timing 774 between each transmitted packet and subsequent measurement. 775 Principally, two different streams are used in IPPM metrics, Poisson 776 distributed as described in [RFC2330] and Periodic as described in 777 [RFC3432]. Both Poisson and Periodic have their own unique 778 parameters, and the relevant set of parameters names and values 779 should be included either in the Fixed Parameters column or in the 780 Run-time parameter column. 782 7.3.3. Traffic Filter 784 This column applies to Performance Metrics that observe packets 785 flowing through (the device with) the measurement agent i.e. that is 786 not necessarily addressed to the measurement agent. This includes 787 but is not limited to Passive Metrics. The filter specifies the 788 traffic that is measured. This includes protocol field values/ 789 ranges, such as address ranges, and flow or session identifiers. 791 The traffic filter itself depends on needs of the metric itself and a 792 balance of operators measurement needs and user's need for privacy. 793 Mechanics for conveying the filter criteria might be the BPF (Berkley 794 Packet Filter) or PSAMP [RFC5475] Property Match Filtering which 795 reuses IPFIX [RFC7012]. An example BPF string for matching TCP/80 796 traffic to remote destination net 192.0.2.0/24 would be "dst net 797 192.0.2.0/24 and tcp dst port 80". More complex filter engines might 798 be supported by the implementation that might allow for matching 799 using Deep Packet Inspection (DPI) technology. 801 The traffic filter includes the following information: 803 Type: the type of traffic filter used, e.g. BPF, PSAMP, OpenFlow 804 rule, etc. as defined by a normative reference 806 Value: the actual set of rules expressed 808 7.3.4. Sampling Distribution 810 The sampling distribution defines out of all the packets that match 811 the traffic filter, which one of those are actually used for the 812 measurement. One possibility is "all" which implies that all packets 813 matching the Traffic filter are considered, but there may be other 814 sampling strategies. It includes the following information: 816 Value: the name of the sampling distribution 818 Reference definition: pointer to the specification where the 819 sampling distribution is properly defined. 821 The sampling distribution may require parameters. In case such 822 parameters are needed, they should be included either in the Fixed 823 parameter column or in the run time parameter column, depending on 824 wether they will be fixed or will be an input for the metric. 826 Sampling and Filtering Techniques for IP Packet Selection are 827 documented in the PSAMP (Packet Sampling) [RFC5475], while the 828 Framework for Packet Selection and Reporting, [RFC5474] provides more 829 background information. The sampling distribution parameters might 830 be expressed in terms of the Information Model for Packet Sampling 831 Exports, [RFC5477], and the Flow Selection Techniques, [RFC7014]. 833 7.3.5. Run-time Parameters 835 Run-Time Parameters are Parameters that must be determined, 836 configured into the measurement system, and reported with the results 837 for the context to be complete. However, the values of these 838 parameters is not specified in the Performance Metrics Registry (like 839 the Fixed Parameters), rather these parameters are listed as an aid 840 to the measurement system implementer or user (they must be left as 841 variables, and supplied on execution). 843 Where metrics supply a list of Parameters as part of their 844 descriptive template, a sub-set of the Parameters will be designated 845 as Run-Time Parameters. 847 Parameters MUST have well defined names. For human readers, the 848 hanging indent style is preferred, and the names and definitions that 849 do not appear in the Reference Method Specification MUST appear in 850 this column. 852 A Data Format for each Run-time Parameter MUST be specified in this 853 column, to simplify the control and implementation of measurement 854 devices. For example, parameters that include an IPv4 address can be 855 encoded as a 32 bit integer (i.e. binary base64 encoded value) or ip- 856 address as defined in [RFC6991]. The actual encoding(s) used must be 857 explicitly defined for each Run-time parameter. IPv6 addresses and 858 options MUST be accomodated, allowing Registered Metrics to be used 859 in either address family. 861 Examples of Run-time Parameters include IP addresses, measurement 862 point designations, start times and end times for measurement, and 863 other information essential to the method of measurement. 865 7.3.6. Role 867 In some method of measurements, there may be several roles defined 868 e.g. on a one-way packet delay active measurement, there is one 869 measurement agent that generates the packets and the other one that 870 receives the packets. This column contains the name of the role for 871 this particular entry. In the previous example, there should be two 872 entries in the registry, one for each role, so that when a 873 measurement agent is instructed to perform the one way delay source 874 metric know that it is supposed to generate packets. The values for 875 this field are defined in the reference method of measurement. 877 7.4. Output Category 879 For entries which involve a stream and many singleton measurements, a 880 statistic may be specified in this column to summarize the results to 881 a single value. If the complete set of measured singletons is 882 output, this will be specified here. 884 Some metrics embed one specific statistic in the reference metric 885 definition, while others allow several output types or statistics. 887 7.4.1. Type 889 This column contains the name of the output type. The output type 890 defines a single type of result that the metric produces. It can be 891 the raw results (packet send times and singleton metrics), or it can 892 be a summary statistic. The specification of the output type MUST 893 define the format of the output. In some systems, format 894 specifications will simplify both measurement implementation and 895 collection/storage tasks. Note that if two different statistics are 896 required from a single measurement (for example, both "Xth percentile 897 mean" and "Raw"), then a new output type must be defined ("Xth 898 percentile mean AND Raw"). 900 7.4.2. Reference Definition 902 This column contains a pointer to the specification where the output 903 type is defined 905 7.4.3. Metric Units 907 The measured results must be expressed using some standard dimension 908 or units of measure. This column provides the units. 910 When a sample of singletons (see [RFC2330] for definitions of these 911 terms) is collected, this entry will specify the units for each 912 measured value. 914 7.5. Administrative information 916 7.5.1. Status 918 The status of the specification of this Registered Performance 919 Metric. Allowed values are 'current' and 'deprecated'. All newly 920 defined Information Elements have 'current' status. 922 7.5.2. Requester 924 The requester for the Registered Performance Metric. The requester 925 MAY be a document, such as RFC, or person. 927 7.5.3. Revision 929 The revision number of a Registered Performance Metric, starting at 0 930 for Registered Performance Metrics at time of definition and 931 incremented by one for each revision. 933 7.5.4. Revision Date 935 The date of acceptance or the most recent revision for the Registered 936 Performance Metric. 938 7.6. Comments and Remarks 940 Besides providing additional details which do not appear in other 941 categories, this open Category (single column) allows for unforeseen 942 issues to be addressed by simply updating this informational entry. 944 8. The Life-Cycle of Registered Performance Metrics 946 Once a Performance Metric or set of Performance Metrics has been 947 identified for a given application, candidate Performance Metrics 948 Registry entry specifications in accordance with Section 7 are 949 submitted to IANA to follow the process for review by the Performance 950 Metric Experts, as defined below. This process is also used for 951 other changes to the Performance Metric Registry, such as deprecation 952 or revision, as described later in this section. 954 It is also desirable that the author(s) of a candidate Performance 955 Metrics Registry entry seek review in the relevant IETF working 956 group, or offer the opportunity for review on the WG mailing list. 958 8.1. Adding new Performance Metrics to the Performance Metrics Registry 960 Requests to change Registered Performance Metrics in the Performance 961 Metric Registry are submitted to IANA, which forwards the request to 962 a designated group of experts (Performance Metric Experts) appointed 963 by the IESG; these are the reviewers called for by the Expert Review 964 RFC5226 policy defined for the Performance Metric Registry. The 965 Performance Metric Experts review the request for such things as 966 compliance with this document, compliance with other applicable 967 Performance Metric-related RFCs, and consistency with the currently 968 defined set of Registered Performance Metrics. 970 Authors are expected to review compliance with the specifications in 971 this document to check their submissions before sending them to IANA. 973 The Performance Metric Experts should endeavor to complete referred 974 reviews in a timely manner. If the request is acceptable, the 975 Performance Metric Experts signify their approval to IANA, which 976 updates the Performance Metric Registry. If the request is not 977 acceptable, the Performance Metric Experts can coordinate with the 978 requester to change the request to be compliant. The Performance 979 Metric Experts may also choose in exceptional circumstances to reject 980 clearly frivolous or inappropriate change requests outright. 982 This process should not in any way be construed as allowing the 983 Performance Metric Experts to overrule IETF consensus. Specifically, 984 any Registered Performance Metrics that were added with IETF 985 consensus require IETF consensus for revision or deprecation. 987 Decisions by the Performance Metric Experts may be appealed as in 988 Section 7 of RFC5226. 990 8.2. Revising Registered Performance Metrics 992 A request for Revision is only permissible when the changes maintain 993 backward-compatibility with implementations of the prior Performance 994 Metrics Registry entry describing a Registered Performance Metric 995 (entries with lower revision numbers, but the same Identifier and 996 Name). 998 The purpose of the Status field in the Performance Metric Registry is 999 to indicate whether the entry for a Registered Performance Metric is 1000 'current' or 'deprecated'. 1002 In addition, no policy is defined for revising the Performance Metric 1003 entries in the IANA Regsirty or addressing errors therein. To be 1004 certain, changes and deprecations within the Performance Metric 1005 Registry are not encouraged, and should be avoided to the extent 1006 possible. However, in recognition that change is inevitable, the 1007 provisions of this section address the need for revisions. 1009 Revisions are initiated by sending a candidate Registered Performance 1010 Metric definition to IANA, as in Section 8, identifying the existing 1011 Performance Metrics Registry entry. 1013 The primary requirement in the definition of a policy for managing 1014 changes to existing Registered Performance Metrics is avoidance of 1015 interoperability problems; Performance Metric Experts must work to 1016 maintain interoperability above all else. Changes to Registered 1017 Performance Metrics may only be done in an inter-operable way; 1018 necessary changes that cannot be done in a way to allow 1019 interoperability with unchanged implementations must result in the 1020 creation of a new Registered Performance Metric and possibly the 1021 deprecation of the earlier metric. 1023 A change to a Registered Performance Metric is held to be backward- 1024 compatible only when: 1026 1. "it involves the correction of an error that is obviously only 1027 editorial; or" 1029 2. "it corrects an ambiguity in the Registered Performance Metric's 1030 definition, which itself leads to issues severe enough to prevent 1031 the Registered Performance Metric's usage as originally defined; 1032 or" 1034 3. "it corrects missing information in the metric definition without 1035 changing its meaning (e.g., the explicit definition of 'quantity' 1036 semantics for numeric fields without a Data Type Semantics 1037 value); or" 1039 4. "it harmonizes with an external reference that was itself 1040 corrected." 1042 If an Performance Metric revision is deemed permissible by the 1043 Performance Metric Experts, according to the rules in this document, 1044 IANA makes the change in the Performance Metric Registry. The 1045 requester of the change is appended to the requester in the 1046 Performance Metrics Registry. 1048 Each Registered Performance Metric in the Performance Metrics 1049 Registry has a revision number, starting at zero. Each change to a 1050 Registered Performance Metric following this process increments the 1051 revision number by one. 1053 When a revised Registered Performance Metric is accepted into the 1054 Performance Metric Registry, the date of acceptance of the most 1055 recent revision is placed into the revision Date column of the 1056 registry for that Registered Performance Metric. 1058 Where applicable, additions to Registered Performance Metrics in the 1059 form of text Comments or Remarks should include the date, but such 1060 additions may not constitute a revision according to this process. 1062 Older version(s) of the updated metric entries are kept in the 1063 registry for archival purposes. The older entries are kept with all 1064 fields unmodified (version, revision date) except for the status 1065 field that is changed to "Deprecated". 1067 8.3. Deprecating Registered Performance Metrics 1069 Changes that are not permissible by the above criteria for Registered 1070 Performance Metric's revision may only be handled by deprecation. A 1071 Registered Performance Metric MAY be deprecated and replaced when: 1073 1. "the Registered Performance Metric definition has an error or 1074 shortcoming that cannot be permissibly changed as in 1075 Section Revising Registered Performance Metrics; or" 1077 2. "the deprecation harmonizes with an external reference that was 1078 itself deprecated through that reference's accepted deprecation 1079 method; or" 1081 A request for deprecation is sent to IANA, which passes it to the 1082 Performance Metric Expert for review. When deprecating an 1083 Performance Metric, the Performance Metric description in the 1084 Performance Metric Registry must be updated to explain the 1085 deprecation, as well as to refer to any new Performance Metrics 1086 created to replace the deprecated Performance Metric. 1088 The revision number of a Registered Performance Metric is incremented 1089 upon deprecation, and the revision Date updated, as with any 1090 revision. 1092 The use of deprecated Registered Performance Metrics should result in 1093 a log entry or human-readable warning by the respective application. 1095 Names and Metric ID of deprecated Registered Performance Metrics must 1096 not be reused. 1098 The deprecated entries are kept with all fields unmodified, except 1099 the version, revision date, and the status field (changed to 1100 "Deprecated"). 1102 9. Security considerations 1104 This draft doesn't introduce any new security considerations for the 1105 Internet. However, the definition of Performance Metrics may 1106 introduce some security concerns, and should be reviewed with 1107 security in mind. 1109 10. IANA Considerations 1111 This document specifies the procedure for Performance Metrics 1112 Registry setup. IANA is requested to create a new registry for 1113 Performance Metrics called "Registered Performance Metrics". This 1114 Registry will contain the following Summary columns: 1116 Identifier: 1118 Name: 1120 URIs: 1122 Description: 1124 Reference: 1126 Change Controller: 1128 Descriptions of these columns and additional information found in the 1129 template for registry entries (categories and columns) are further 1130 defined in section Section 7. 1132 The "Identifier" 0 should be Reserved. "The Identifier" values from 1133 64512 to 65536 are reserved for private use. 1135 Names starting with the prefix Priv_ are reserved for private use, 1136 and are not considered for registration. The "Name" column entries 1137 are further defined in section Section 7. 1139 The "Name" (or "URIs" ??) column will have a link to the full 1140 template. 1142 The "Reference" column will include an RFC, an approved specification 1143 from another standards body, or the contact person. 1145 New assignments for Performance Metric Registry will be administered 1146 by IANA through Expert Review [RFC5226], i.e., review by one of a 1147 group of experts, the Performance Metric Experts, who are appointed 1148 by the IESG upon recommendation of the Transport Area Directors. The 1149 experts can be initially drawn from the Working Group Chairs and 1150 document editors of the Performance Metrics Directorate among other 1151 sources of experts. 1153 >>> ok to here, pending the use of "Name" or URIs column question. 1155 This document requests the allocation of the URI prefix 1156 urn:ietf:params:ippm:metric for the purpose of generating URIs for 1157 Registered Performance Metrics. Note: an alternate proposal which 1158 avoids the "params" namspace for protocols is urn:ietf:metric: . 1160 Extensions of the Registry require IETF Standards Action. Two forms 1161 of registry extension are envisaged: 1163 1. Adding columns or both categories and columns, to accommodate 1164 unanticipated aspects of new measurements and metric categories. 1165 Note: this form of extension may be well-served by adding a 1166 format version number column now, then existing entries (without 1167 the extended column) can be left as-is, if desired. 1169 2. Additional values for the various elements used in the Metric 1170 "Name" column. A candidate Metric Entry RFC would propose one or 1171 more new element values required to describe the entry. 1173 11. Acknowledgments 1175 Thanks to Brian Trammell and Bill Cerveny, IPPM chairs, for leading 1176 some brainstorming sessions on this topic. Thanks to Barbara Stark 1177 and Juergen Schoenwaelder for the detailed feedback and suggestions. 1178 Thanks to Andrew McGregor for suggestions on metric naming. Thanks 1179 to Michelle Cotton for her early IANA review, and to Amanda Barber 1180 for answering questions related to the presentation of the registry 1181 and accessibility of the complete template via URL. 1183 12. References 1185 12.1. Normative References 1187 [RFC2026] Bradner, S., "The Internet Standards Process -- Revision 1188 3", BCP 9, RFC 2026, DOI 10.17487/RFC2026, October 1996, 1189 . 1191 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1192 Requirement Levels", BCP 14, RFC 2119, 1193 DOI 10.17487/RFC2119, March 1997, 1194 . 1196 [RFC2141] Moats, R., "URN Syntax", RFC 2141, DOI 10.17487/RFC2141, 1197 May 1997, . 1199 [RFC2330] Paxson, V., Almes, G., Mahdavi, J., and M. Mathis, 1200 "Framework for IP Performance Metrics", RFC 2330, 1201 DOI 10.17487/RFC2330, May 1998, 1202 . 1204 [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform 1205 Resource Identifier (URI): Generic Syntax", STD 66, 1206 RFC 3986, DOI 10.17487/RFC3986, January 2005, 1207 . 1209 [RFC4148] Stephan, E., "IP Performance Metrics (IPPM) Metrics 1210 Registry", BCP 108, RFC 4148, DOI 10.17487/RFC4148, August 1211 2005, . 1213 [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an 1214 IANA Considerations Section in RFCs", BCP 26, RFC 5226, 1215 DOI 10.17487/RFC5226, May 2008, 1216 . 1218 [RFC6248] Morton, A., "RFC 4148 and the IP Performance Metrics 1219 (IPPM) Registry of Metrics Are Obsolete", RFC 6248, 1220 DOI 10.17487/RFC6248, April 2011, 1221 . 1223 [RFC6390] Clark, A. and B. Claise, "Guidelines for Considering New 1224 Performance Metric Development", BCP 170, RFC 6390, 1225 DOI 10.17487/RFC6390, October 2011, 1226 . 1228 [RFC6576] Geib, R., Ed., Morton, A., Fardid, R., and A. Steinmitz, 1229 "IP Performance Metrics (IPPM) Standard Advancement 1230 Testing", BCP 176, RFC 6576, DOI 10.17487/RFC6576, March 1231 2012, . 1233 12.2. Informative References 1235 [RFC2679] Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way 1236 Delay Metric for IPPM", RFC 2679, DOI 10.17487/RFC2679, 1237 September 1999, . 1239 [RFC7679] Almes, G., Kalidindi, S., Zekauskas, M., and A. Morton, 1240 Ed., "A One-Way Delay Metric for IP Performance Metrics 1241 (IPPM)", STD 81, RFC 7679, DOI 10.17487/RFC7679, January 1242 2016, . 1244 [RFC2681] Almes, G., Kalidindi, S., and M. Zekauskas, "A Round-trip 1245 Delay Metric for IPPM", RFC 2681, DOI 10.17487/RFC2681, 1246 September 1999, . 1248 [RFC3393] Demichelis, C. and P. Chimento, "IP Packet Delay Variation 1249 Metric for IP Performance Metrics (IPPM)", RFC 3393, 1250 DOI 10.17487/RFC3393, November 2002, 1251 . 1253 [RFC3432] Raisanen, V., Grotefeld, G., and A. Morton, "Network 1254 performance measurement with periodic streams", RFC 3432, 1255 DOI 10.17487/RFC3432, November 2002, 1256 . 1258 [RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V. 1259 Jacobson, "RTP: A Transport Protocol for Real-Time 1260 Applications", STD 64, RFC 3550, DOI 10.17487/RFC3550, 1261 July 2003, . 1263 [RFC3611] Friedman, T., Ed., Caceres, R., Ed., and A. Clark, Ed., 1264 "RTP Control Protocol Extended Reports (RTCP XR)", 1265 RFC 3611, DOI 10.17487/RFC3611, November 2003, 1266 . 1268 [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session 1269 Description Protocol", RFC 4566, DOI 10.17487/RFC4566, 1270 July 2006, . 1272 [RFC5474] Duffield, N., Ed., Chiou, D., Claise, B., Greenberg, A., 1273 Grossglauser, M., and J. Rexford, "A Framework for Packet 1274 Selection and Reporting", RFC 5474, DOI 10.17487/RFC5474, 1275 March 2009, . 1277 [RFC5475] Zseby, T., Molina, M., Duffield, N., Niccolini, S., and F. 1278 Raspall, "Sampling and Filtering Techniques for IP Packet 1279 Selection", RFC 5475, DOI 10.17487/RFC5475, March 2009, 1280 . 1282 [RFC5477] Dietz, T., Claise, B., Aitken, P., Dressler, F., and G. 1283 Carle, "Information Model for Packet Sampling Exports", 1284 RFC 5477, DOI 10.17487/RFC5477, March 2009, 1285 . 1287 [RFC5481] Morton, A. and B. Claise, "Packet Delay Variation 1288 Applicability Statement", RFC 5481, DOI 10.17487/RFC5481, 1289 March 2009, . 1291 [RFC5905] Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch, 1292 "Network Time Protocol Version 4: Protocol and Algorithms 1293 Specification", RFC 5905, DOI 10.17487/RFC5905, June 2010, 1294 . 1296 [RFC6035] Pendleton, A., Clark, A., Johnston, A., and H. Sinnreich, 1297 "Session Initiation Protocol Event Package for Voice 1298 Quality Reporting", RFC 6035, DOI 10.17487/RFC6035, 1299 November 2010, . 1301 [RFC6776] Clark, A. and Q. Wu, "Measurement Identity and Information 1302 Reporting Using a Source Description (SDES) Item and an 1303 RTCP Extended Report (XR) Block", RFC 6776, 1304 DOI 10.17487/RFC6776, October 2012, 1305 . 1307 [RFC6792] Wu, Q., Ed., Hunt, G., and P. Arden, "Guidelines for Use 1308 of the RTP Monitoring Framework", RFC 6792, 1309 DOI 10.17487/RFC6792, November 2012, 1310 . 1312 [RFC7003] Clark, A., Huang, R., and Q. Wu, Ed., "RTP Control 1313 Protocol (RTCP) Extended Report (XR) Block for Burst/Gap 1314 Discard Metric Reporting", RFC 7003, DOI 10.17487/RFC7003, 1315 September 2013, . 1317 [RFC7012] Claise, B., Ed. and B. Trammell, Ed., "Information Model 1318 for IP Flow Information Export (IPFIX)", RFC 7012, 1319 DOI 10.17487/RFC7012, September 2013, 1320 . 1322 [RFC7014] D'Antonio, S., Zseby, T., Henke, C., and L. Peluso, "Flow 1323 Selection Techniques", RFC 7014, DOI 10.17487/RFC7014, 1324 September 2013, . 1326 [RFC7594] Eardley, P., Morton, A., Bagnulo, M., Burbridge, T., 1327 Aitken, P., and A. Akhter, "A Framework for Large-Scale 1328 Measurement of Broadband Performance (LMAP)", RFC 7594, 1329 DOI 10.17487/RFC7594, September 2015, 1330 . 1332 [I-D.ietf-ippm-active-passive] 1333 Morton, A., "Active and Passive Metrics and Methods (and 1334 everything in-between, or Hybrid)", draft-ietf-ippm- 1335 active-passive-06 (work in progress), January 2016. 1337 [RFC7799] Morton, A., "Active and Passive Metrics and Methods (with 1338 Hybrid Types In-Between)", RFC 7799, DOI 10.17487/RFC7799, 1339 May 2016, . 1341 [I-D.ietf-ippm-initial-registry] 1342 Morton, A., Bagnulo, M., Eardley, P., and K. D'Souza, 1343 "Initial Performance Metric Registry Entries", draft-ietf- 1344 ippm-initial-registry-01 (work in progress), July 2016. 1346 [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", 1347 RFC 6991, DOI 10.17487/RFC6991, July 2013, 1348 . 1350 Authors' Addresses 1351 Marcelo Bagnulo 1352 Universidad Carlos III de Madrid 1353 Av. Universidad 30 1354 Leganes, Madrid 28911 1355 SPAIN 1357 Phone: 34 91 6249500 1358 Email: marcelo@it.uc3m.es 1359 URI: http://www.it.uc3m.es 1361 Benoit Claise 1362 Cisco Systems, Inc. 1363 De Kleetlaan 6a b1 1364 1831 Diegem 1365 Belgium 1367 Email: bclaise@cisco.com 1369 Philip Eardley 1370 BT 1371 Adastral Park, Martlesham Heath 1372 Ipswich 1373 ENGLAND 1375 Email: philip.eardley@bt.com 1377 Al Morton 1378 AT&T Labs 1379 200 Laurel Avenue South 1380 Middletown, NJ 1381 USA 1383 Email: acmorton@att.com 1385 Aamer Akhter 1386 Consultant 1387 118 Timber Hitch 1388 Cary, NC 1389 USA 1391 Email: aakhter@gmail.com