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Schulzrinne 3 Internet-Draft Columbia U. 4 Intended status: Standards Track March 4, 2007 5 Expires: September 5, 2007 7 A Uniform Resource Name (URN) for Services 8 draft-ietf-ecrit-service-urn-06 10 Status of this Memo 12 By submitting this Internet-Draft, each author represents that any 13 applicable patent or other IPR claims of which he or she is aware 14 have been or will be disclosed, and any of which he or she becomes 15 aware will be disclosed, in accordance with Section 6 of BCP 79. 17 Internet-Drafts are working documents of the Internet Engineering 18 Task Force (IETF), its areas, and its working groups. Note that 19 other groups may also distribute working documents as Internet- 20 Drafts. 22 Internet-Drafts are draft documents valid for a maximum of six months 23 and may be updated, replaced, or obsoleted by other documents at any 24 time. It is inappropriate to use Internet-Drafts as reference 25 material or to cite them other than as "work in progress." 27 The list of current Internet-Drafts can be accessed at 28 http://www.ietf.org/ietf/1id-abstracts.txt. 30 The list of Internet-Draft Shadow Directories can be accessed at 31 http://www.ietf.org/shadow.html. 33 This Internet-Draft will expire on September 5, 2007. 35 Copyright Notice 37 Copyright (C) The IETF Trust (2007). 39 Abstract 41 The content of many communication services depends on the context, 42 such as the user's location. We describe a 'service' URN that allows 43 to identify context-dependent services that can be resolved in a 44 distributed manner. 46 Table of Contents 48 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 49 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 50 3. Registration Template . . . . . . . . . . . . . . . . . . . . 5 51 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7 52 4.1. New Service-Identifying Labels . . . . . . . . . . . . . . 7 53 4.2. Sub-Services for the 'sos' Service . . . . . . . . . . . . 8 54 4.3. Sub-Services for the 'counseling' Service . . . . . . . . 9 55 4.4. Initial IANA Registration . . . . . . . . . . . . . . . . 9 56 5. Internationalization Considerations . . . . . . . . . . . . . 10 57 6. Security Considerations . . . . . . . . . . . . . . . . . . . 10 58 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 11 59 7.1. Normative References . . . . . . . . . . . . . . . . . . . 11 60 7.2. Informative References . . . . . . . . . . . . . . . . . . 11 61 Appendix A. Alternative Approaches Considered . . . . . . . . . . 12 62 Appendix B. Acknowledgments . . . . . . . . . . . . . . . . . . . 13 63 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 13 64 Intellectual Property and Copyright Statements . . . . . . . . . . 15 66 1. Introduction 68 In existing telecommunications systems, there are many well-known 69 communication and information services that are offered by loosely 70 coordinated entities across a large geographic region, with well- 71 known identifiers. Some of the services are operated by governments 72 or regulated monopolies, others by competing commercial enterprises. 73 Examples include emergency services (reached by dialing 9-1-1 in 74 North America, 1-1-2 in Europe), community services and volunteer 75 opportunities (2-1-1 in some regions of the United States), telephone 76 directory and repair services (4-1-1 and 6-1-1 in the United States 77 and Canada), government information services (3-1-1 in some cities in 78 the United States), lawyer referral services (1-800-LAWYER), car 79 roadside assistance (automobile clubs) and pizza delivery services. 80 Unfortunately, almost all of them are limited in scope to a single 81 country or possibly a group of countries, such as those belonging to 82 the North American Numbering Plan or the European Union. The same 83 identifiers are often used for other purposes outside that region, 84 making accessing such services difficult when users travel or use 85 devices produced outside their home country. 87 These services are characterized by long-term stability of user- 88 visible identifiers, decentralized administration of the underlying 89 service and a well-defined resolution or mapping mechanism. For 90 example, there is no national coordination or call center for "9-1-1" 91 in the United States; rather, various local government organizations 92 cooperate to provide this service, based on jurisdictions. We use 93 the terms resolution and mapping interchangeably. 95 In this document, we propose a URN namespace that, together with 96 resolution protocols beyond the scope of this document, allows us to 97 define such global, well-known services, while distributing the 98 actual implementation across a large number of service-providing 99 entities. There are many ways to divide provision of such services, 100 such as dividing responsibility by geographic region or by the 101 service provider a user chooses. In addition, users can choose 102 different mapping service providers that in turn manage how 103 geographic locations are mapped to service providers. 105 Availability of such service identifiers allows end systems to convey 106 information about the desired service to other network entities. For 107 example, an IP phone could have a special set of short cuts, address 108 book entries or buttons that invoke emergency services. When such a 109 service identifier is put into the outgoing Session Initiation 110 Protocol (SIP) [4] message, it allows SIP proxies to unambiguously 111 take actions, as it would not be practical to configure them with 112 dial strings and emergency numbers used throughout the world. Hence, 113 such service identifiers make it possible to delegate routing 114 decisions to third parties and to mark certain requests as having 115 special characteristics while preventing these characteristics from 116 being accidentally invoked. 118 This URN identifies services independent of the particular protocol 119 that is used to request or deliver the service. The URN may appear 120 in protocols that allow general URIs, such as the SIP [4] request 121 URIs, web pages or mapping protocols. 123 The service URN is a protocol element and generally not expected to 124 be visible to humans. For example, it is expected that callers will 125 still dial the emergency number '9-1-1' in the United States to reach 126 emergency services. In some other cases, speed dial buttons might 127 identify the service, as is common practice on hotel phones today. 128 (Speed dial buttons for summoning emergency help are considered 129 inappropriate by most emergency services professionals, at least for 130 mobile devices, as they are too prone to being triggered 131 accidentally.) 133 The translation of service dial strings or service numbers to service 134 URNs in the end host is beyond the scope of this document. These 135 translations likely depend on the location of the caller and may be 136 many-to-one, i.e., several service numbers may map to one service 137 URN. For example, a phone for a traveler could recognize the 138 emergency service number for both the traveler's home location and 139 the traveler's visited location, mapping both to the same universal 140 service URN, urn:service:sos. 142 Since service URNs are not routable, a SIP proxy or user agent has to 143 translate the service URN into a routable URI for a location- 144 appropriate service provider, such as a SIP URL. LoST [17] is 145 expected to be used as a resolution system for mapping service URNs 146 to URLs based on geographic location. In the future, there may be 147 several such protocols, possibly different ones for different 148 services. 150 Services are described by top-level service type, and may contain a 151 hierarchy of sub-services further describing the service, as outlined 152 in Section 3. 154 We discuss alternative approaches for creating service identifiers, 155 and why they are unsatisfactory, in Appendix A. 157 2. Terminology 159 In this document, the key words "MUST", "MUST NOT", "REQUIRED", 160 "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", 161 and "OPTIONAL" are to be interpreted as described in RFC 2119 [2]. 163 Terminology specific to emergency services is defined in [19]. 165 3. Registration Template 167 Below, we include the registration template for the URN scheme 168 according to RFC 3406 [12]. 169 Namespace ID: service 170 Registration Information: Registration version: 1; registration 171 date: 2006-04-02 173 Declared registrant of the namespace: 174 Registering organization: IETF ECRIT Working Group 175 Designated contact: Henning Schulzrinne 176 Designated contact email: hgs@cs.columbia.edu 178 Declaration of syntactic structure: The URN consists of a 179 hierarchical service identifier, with a sequence of labels 180 separated by periods. The left-most label is the most significant 181 one and is called 'top-level service', while names to the right 182 are called 'sub-services'. The set of allowable characters is the 183 same as that for domain names [1] and a subset of the labels 184 allowed in [5]. Labels are case-insensitive and MUST be specified 185 in all lower-case. For any given service URN, service-identifiers 186 can be removed right-to-left and the resulting URN is still valid, 187 referring a more generic service. In other words, if a service 188 'x.y.z' exists, the URNs 'x' and 'x.y' are also valid service 189 URNs. 191 "URN:service:" service 192 service = top-level *("." sub-service) 193 let-dig = ALPHA / DIGIT 194 let-dig-hyp = let-dig / '-' 195 sub-service = let-dig [ *let-dig-hyp let-dig ] 196 top-level = let-dig [ *25let-dig-hyp let-dig ] 198 Relevant ancillary documentation: None 200 Community considerations: The service URN is believed to be relevant 201 to a large cross-section of Internet users, including both 202 technical and non-technical users, on a variety of devices, but 203 particularly for mobile and nomadic users. The service URN will 204 allow Internet users needing services to identify the service by 205 kind, without having to determine manually who provides the 206 particular service in the user's current context, e.g., at the 207 user's current location. For example, travelers will be able to 208 use their mobile devices to request emergency services without 209 having to know the emergency dial string of the visited country. 210 The assignment of identifiers is described in the IANA 211 Considerations (Section 4). The service URN does not prescribe a 212 particular resolution mechanism, but it is assumed that a number 213 of different entities could operate and offer such mechanisms. 215 Namespace considerations: There do not appear to be other URN 216 namespaces that serve the same need of uniquely identifying 217 widely-available communication and information services. Unlike 218 most other currently registered URN namespaces, the service URN 219 does not identify documents and protocol objects (e.g., [9], [10], 220 [15], [16]), types of telecommunications equipment [14], people or 221 organizations [8]. tel URIs [13] identify telephone numbers, but 222 numbers commonly identifying services, such as 911 or 112, are 223 specific to a particular region or country. 225 Identifier uniqueness considerations: A service URN identifies a 226 logical service, specified in the service registration (see IANA 227 Considerations (Section 4)). Resolution of the URN, if 228 successful, will return a particular instance of the service, and 229 this instance may be different even for two users making the same 230 request in the same place at the same time; the logical service 231 identified by the URN, however, is persistent and unique. Service 232 URNs MUST be unique for each unique service; this is guaranteed 233 through the registration of each service within this namespace, 234 described in Section 4. 236 Identifier persistence considerations: The 'service' URN for the 237 same service is expected to be persistent, although there 238 naturally cannot be a guarantee that a particular service will 239 continue to be available globally or at all times. 241 Process of identifier assignment: The process of identifier 242 assignment is described in the IANA Considerations (Section 4). 244 Process for identifier resolution: There is no single global 245 resolution service for 'service' URNs. However, each top-level 246 service can provide a set of mapping protocols to be used with 247 'service' URNs of that service. 249 Rules for Lexical Equivalence: 'service' identifiers are compared 250 according to case-insensitive string equality. 252 Conformance with URN Syntax: The BNF in the 'Declaration of 253 syntactic structure' above constrains the syntax for this URN 254 scheme. 256 Validation mechanism: Validation determines whether a given string 257 is currently a validly-assigned URN [12]. Due to the distributed 258 nature of the mapping mechanism and since not all services are 259 available everywhere and not all mapping servers may be configured 260 with all current service registrations, validation in this sense 261 is not possible. Also, the discovery mechanism for the mapping 262 mechanism may not be configured with all current top-level 263 services. 265 Scope: The scope for this URN is public and global. 267 4. IANA Considerations 269 This section registers a new URN scheme with the registration 270 template provided in Section 3. 272 Below, Section 4.1 details how to register new service-identifying 273 labels. Descriptions of sub-services for the first two services to 274 be registered, sos and counseling, are given in Section 4.2 and 275 Section 4.3, respectively. Finally, Section 4.4 contains the initial 276 registration table. 278 4.1. New Service-Identifying Labels 280 Services and sub-services are identified by labels managed by IANA, 281 according to the processes outlined in [3] in a new registry called 282 "Service URN Labels". Thus, creating a new service requires IANA 283 action. The policy for adding top-level service labels is 'Standards 284 Action'. (This document defines the top-level service 'sos' and 285 'counseling'.) The policy for assigning labels to sub-services may 286 differ for each top-level service designation and MUST be defined by 287 the document describing the top-level service. 289 Entries in the registration table have the following format 291 Service Reference Description 292 -------------------------------------------------------------------- 293 foo RFCxyz Brief description of the 'foo' top-level service 294 foo.bar RFCabc Description of the 'foo.bar' service 296 To allow use within the constraints of S-NAPTR [5], all top-level 297 service names MUST NOT exceed 27 characters. 299 4.2. Sub-Services for the 'sos' Service 301 This section defines the first service registration within the IANA 302 registry defined in Section 4.1, using the top-level service label 303 'sos'. 305 The 'sos' service type describes emergency services requiring an 306 immediate response, typically offered by various branches of the 307 government or other public institutions. Additional sub-services can 308 be added after expert review and must be of general public interest 309 and have a similar emergency nature. The expert is designated by the 310 ECRIT working group, its successor, or, in their absence, the IESG. 311 The expert review should only approve emergency services that are 312 offered widely and in different countries, with approximately the 313 same caller expectation in terms of services rendered. The 'sos' 314 service is not meant to invoke general government, public 315 information, counseling or social services. 317 urn:service:sos The generic 'sos' service reaches a public safety 318 answering point (PSAP) which in turn dispatches aid appropriate to 319 the emergency. It encompasses all of the services listed below. 320 urn:service:sos.ambulance This service identifier reaches an 321 ambulance service that provides emergency medical assistance and 322 transportation. 323 urn:service:sos.animal-control Animal control is defined as control 324 of dogs, cats, and domesticated or undomesticated animals. 325 urn:service:sos.fire The 'fire' service identifier summons the fire 326 service, also known as the fire brigade or fire department. 327 urn:service:sos.gas The 'gas' service allows the reporting of 328 natural gas (and other flammable gas) leaks or other natural gas 329 emergencies. 330 urn:service:sos.marine The 'marine' service refers to maritime 331 search and rescue services such as those offered by the coast 332 guard, lifeboat or surf lifesavers. 333 urn:service:sos.mountain The 'mountain' service refers to mountain 334 rescue services, i.e., search and rescue activities that occur in 335 a mountainous environment, although the term is sometimes also 336 used to apply to search and rescue in other wilderness 337 environments. 338 urn:service:sos.physician The 'physician' emergency service connects 339 the caller to a physician referral service. 340 urn:service:sos.poison The 'poison' service refers to special 341 information centers set up to inform citizens about how to respond 342 to potential poisoning. These poison control centers maintain a 343 database of poisons and appropriate emergency treatment. 345 urn:service:sos.police The 'police' service refers to the police 346 department or other law enforcement authorities. 348 4.3. Sub-Services for the 'counseling' Service 350 The 'counseling' service type describes services where callers can 351 receive advice and support, often anonymous, but not requiring an 352 emergency response. (Naturally, such services may transfer callers 353 to an emergency service or summon such services if the situation 354 warrants.) Additional sub-services can be added after expert review 355 and should be of general public interest. The expert is chosen in 356 the same manner as describe for the 'sos' service. The expert review 357 should take into account whether these services are offered widely 358 and in different countries, with approximately the same caller 359 expectation in terms of services rendered. 360 urn:service:counseling The generic 'counseling' service reaches a 361 call center that transfers the caller based on his or her specific 362 needs. 364 urn:service:counseling.children The 'children' service refers to 365 counseling and support services that are specifically tailored to 366 the needs of children. Such services may, for example, provide 367 advice to run-aways or victims of child abuse. 369 urn:service:counseling.mental-health The 'mental-health' service 370 refers to the "diagnostic, treatment, and preventive care that 371 helps improve how persons with mental illness feel both physically 372 and emotionally as well as how they interact with other persons." 373 (U.S. Department of Health and Human Services) 375 urn:service:counseling.suicide The 'suicide' service refers to the 376 suicide prevention hotline. 378 4.4. Initial IANA Registration 380 The following table contains the initial IANA registration for 381 emergency and counseling services. 383 Service Reference Description 384 -------------------------------------------------------------------- 385 counseling RFC XYZ Counseling services 386 counseling.children RFC XYZ Counseling for children 387 counseling.mental-health RFC XYZ Mental health counseling 388 counseling.suicide RFC XYZ Suicide prevention hotline 390 sos RFC XYZ Emergency services 391 sos.animal-control RFC XYZ Animal control 392 sos.fire RFC XYZ Fire service 393 sos.gas RFC XYZ Gas leaks and gas emergencies 394 sos.marine RFC XYZ Maritime search and rescue 395 sos.mountain RFC XYZ Mountain rescue 396 sos.physician RFC XYZ Physician referral service 397 sos.poison RFC XYZ Poison control center 398 sos.police RFC XYZ Police, law enforcement 400 [[NOTE TO RFC-EDITOR: Please replace above 'RFC XYZ' reference with 401 the RFC number of this document and remove this note.]] 403 5. Internationalization Considerations 405 The service labels are protocol elements [11] and not normally seen 406 by users. Thus, the character set for these elements is restricted, 407 as described in Section 3. 409 6. Security Considerations 411 As an identifier, the service URN does not appear to raise any 412 particular security issues. The services described by the URN are 413 meant to be well-known, even if the particular service instance is 414 access-controlled, so privacy considerations do not apply to the URN. 415 There are likely no specific privacy issues when including a service 416 URN on a web page, for example. On the other hand, ferrying the URN 417 in a signaling protocol can give attackers information on the kind of 418 service desired by the caller. For example, this makes it easier for 419 the attacker to automatically find all calls for emergency services 420 or directory assistance. Appropriate, protocol-specific security 421 mechanisms need to be implemented for protocols carrying service 422 URNs. The mapping protocol needs to address a number of threats, as 423 detailed in [18]. That document also discusses the security 424 considerations related to the use of the service URN for emergency 425 services. 427 7. References 428 7.1. Normative References 430 [1] Braden, R., "Requirements for Internet Hosts - Application and 431 Support", STD 3, RFC 1123, October 1989. 433 [2] Bradner, S., "Key words for use in RFCs to Indicate Requirement 434 Levels", BCP 14, RFC 2119, March 1997. 436 [3] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA 437 Considerations Section in RFCs", BCP 26, RFC 2434, 438 October 1998. 440 [4] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A., 441 Peterson, J., Sparks, R., Handley, M., and E. Schooler, "SIP: 442 Session Initiation Protocol", RFC 3261, June 2002. 444 [5] Daigle, L. and A. Newton, "Domain-Based Application Service 445 Location Using SRV RRs and the Dynamic Delegation Discovery 446 Service (DDDS)", RFC 3958, January 2005. 448 7.2. Informative References 450 [6] Crocker, D., "MAILBOX NAMES FOR COMMON SERVICES, ROLES AND 451 FUNCTIONS", RFC 2142, May 1997. 453 [7] Resnick, P., "Internet Message Format", RFC 2822, April 2001. 455 [8] Mealling, M., "The Network Solutions Personal Internet Name 456 (PIN): A URN Namespace for People and Organizations", RFC 3043, 457 January 2001. 459 [9] Rozenfeld, S., "Using The ISSN (International Serial Standard 460 Number) as URN (Uniform Resource Names) within an ISSN-URN 461 Namespace", RFC 3044, January 2001. 463 [10] Hakala, J. and H. Walravens, "Using International Standard Book 464 Numbers as Uniform Resource Names", RFC 3187, October 2001. 466 [11] Hoffman, P., "Terminology Used in Internationalization in the 467 IETF", RFC 3536, May 2003. 469 [12] Daigle, L., van Gulik, D., Iannella, R., and P. Faltstrom, 470 "Uniform Resource Names (URN) Namespace Definition Mechanisms", 471 BCP 66, RFC 3406, October 2002. 473 [13] Schulzrinne, H., "The tel URI for Telephone Numbers", RFC 3966, 474 December 2004. 476 [14] Tesink, K. and R. Fox, "A Uniform Resource Name (URN) Namespace 477 for the Common Language Equipment Identifier (CLEI) Code", 478 RFC 4152, August 2005. 480 [15] Kang, S., "Using Universal Content Identifier (UCI) as Uniform 481 Resource Names (URN)", RFC 4179, October 2005. 483 [16] Kameyama, W., "A Uniform Resource Name (URN) Namespace for the 484 TV-Anytime Forum", RFC 4195, October 2005. 486 [17] Hardie, T., "LoST: A Location-to-Service Translation Protocol", 487 draft-ietf-ecrit-lost-04 (work in progress), February 2007. 489 [18] Taylor, T., "Security Threats and Requirements for Emergency 490 Call Marking and Mapping", draft-ietf-ecrit-security-threats-03 491 (work in progress), July 2006. 493 [19] Schulzrinne, H. and R. Marshall, "Requirements for Emergency 494 Context Resolution with Internet Technologies", 495 draft-ietf-ecrit-requirements-12 (work in progress), 496 August 2006. 498 Appendix A. Alternative Approaches Considered 500 The discussions of ways to identify emergency calls has yielded a 501 number of proposals. Since these are occasionally brought up during 502 discussions, we briefly summarize why this document chose not to 503 pursue these solutions. 504 tel:NNN;context=+C This approach uses tel URIs [13]. Here, NNN is 505 the national emergency number, where the country is identified by 506 the context C. This approach is easy for user agents to implement, 507 but hard for proxies and other SIP elements to recognize, as it 508 would have to know about all number-context combinations in the 509 world and track occasional changes. In addition, many of these 510 numbers are being used for other services. For example, the 511 emergency number in Paraguay (00) is also used to call the 512 international operator in the United States. As another example, 513 A number of countries, such as Italy, use 118 as an emergency 514 number, but it also connects to directory assistance in Finland. 516 tel:sos This solution avoids name conflicts, but is not a valid 517 "tel" [13] URI. It also only works if every outbound proxy knows 518 how to route requests to a proxy that can reach emergency services 519 since tel URIs. The SIP URI proposed here only requires a user's 520 home domain to be appropriately configured. 522 sip:sos@domain Earlier work had defined a special user identifier, 523 sos, within the caller's home domain in a SIP URI, for example, 524 sip:sos@example.com. Such a user identifier follows the 525 convention of RFC 2142 [6] and the "postmaster" convention 526 documented in RFC 2822 [7]. This approach had the advantage that 527 dial plans in existing user agents could probably be converted to 528 generate such a URI and that only the home proxy for the domain 529 has to understand the user naming convention. However, it 530 overloads the user part of the URI with specific semantics rather 531 than being opaque, makes routing by the outbound proxy a special 532 case that does not conform to normal SIP request-URI handling 533 rules and is SIP-specific. The mechanism also does not extend 534 readily to other services. 536 SIP URI user parameter: One could create a special URI, such as 537 "aor-domain;user=sos". This avoids the name conflict problem, but 538 requires mechanism-aware user agents that are capable of emitting 539 this special URI. Also, the 'user' parameter is meant to describe 540 the format of the user part of the SIP URI, which this usage does 541 not do. Adding other parameters still leaves unclear what, if 542 any, conventions should be used for the user and domain part of 543 the URL. Neither solution is likely to be backward-compatible 544 with existing clients. 546 Special domain: A special domain, such as "sip:fire@sos.int" could 547 be used to identify emergency calls. This has similar properties 548 as the "tel:sos" URI, except that it is indeed a valid URI. To 549 make this usable, the special domain would have to be operational 550 and point to an appropriate emergency services proxy. Having a 551 single, if logical, emergency services proxy for the whole world 552 seems to have undesirable scaling and administrative properties. 554 Appendix B. Acknowledgments 556 This document is based on discussions with Jonathan Rosenberg and 557 benefited from the comments of Leslie Daigle, Keith Drage, Benja 558 Fallenstein, Paul Kyzivat, Andrew Newton, Brian Rosen, Jonathan 559 Rosenberg, Martin Thomson and Hannes Tschofenig. 561 Author's Address 563 Henning Schulzrinne 564 Columbia University 565 Department of Computer Science 566 450 Computer Science Building 567 New York, NY 10027 568 US 570 Phone: +1 212 939 7004 571 Email: hgs+ecrit@cs.columbia.edu 572 URI: http://www.cs.columbia.edu 574 Full Copyright Statement 576 Copyright (C) The IETF Trust (2007). 578 This document is subject to the rights, licenses and restrictions 579 contained in BCP 78, and except as set forth therein, the authors 580 retain all their rights. 582 This document and the information contained herein are provided on an 583 "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS 584 OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND 585 THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS 586 OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF 587 THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED 588 WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 590 Intellectual Property 592 The IETF takes no position regarding the validity or scope of any 593 Intellectual Property Rights or other rights that might be claimed to 594 pertain to the implementation or use of the technology described in 595 this document or the extent to which any license under such rights 596 might or might not be available; nor does it represent that it has 597 made any independent effort to identify any such rights. 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