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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 14. -- Found old boilerplate from RFC 3978, Section 5.5 on line 1980. -- Found old boilerplate from RFC 3979, Section 5, paragraph 1 on line 1952. -- Found old boilerplate from RFC 3979, Section 5, paragraph 2 on line 1959. -- Found old boilerplate from RFC 3979, Section 5, paragraph 3 on line 1965. ** This document has an original RFC 3978 Section 5.4 Copyright Line, instead of the newer IETF Trust Copyright according to RFC 4748. ** This document has an original RFC 3978 Section 5.5 Disclaimer, instead of the newer disclaimer which includes the IETF Trust according to RFC 4748. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- == No 'Intended status' indicated for this document; assuming Proposed Standard Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- == There are 2 instances of lines with private range IPv4 addresses in the document. If these are generic example addresses, they should be changed to use any of the ranges defined in RFC 6890 (or successor): 192.0.2.x, 198.51.100.x or 203.0.113.x. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the RFC 3978 Section 5.4 Copyright Line does not match the current year == Line 1879 has weird spacing: '...Changes in XM...' == 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). == Using lowercase 'not' together with uppercase 'MUST', 'SHALL', 'SHOULD', or 'RECOMMENDED' is not an accepted usage according to RFC 2119. Please use uppercase 'NOT' together with RFC 2119 keywords (if that is what you mean). Found 'SHOULD not' in this paragraph: The "discovered" host for the "local-network" profile subscription URI is the local IP network domain for the user agent, either provisioned as part of the device's static network configuration or discovered via DHCP. The local network profile subscription URI SHOULD not be remembered if the user agent moves from one local network to another other. The user agent should perform the local network discovery to construct the network profile subscription request URI every time it starts up or network connectivity is regained. -- 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 (July 17, 2005) is 6852 days in the past. Is this intentional? 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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 SIPPING D. Petrie 3 Internet-Draft SIPez LLC. 4 Expires: January 18, 2006 July 17, 2005 6 A Framework for Session Initiation Protocol User Agent Profile Delivery 7 draft-ietf-sipping-config-framework-07.txt 9 Status of this Memo 11 By submitting this Internet-Draft, each author represents that any 12 applicable patent or other IPR claims of which he or she is aware 13 have been or will be disclosed, and any of which he or she becomes 14 aware will be disclosed, in accordance with Section 6 of BCP 79. 16 Internet-Drafts are working documents of the Internet Engineering 17 Task Force (IETF), its areas, and its working groups. Note that 18 other groups may also distribute working documents as Internet- 19 Drafts. 21 Internet-Drafts are draft documents valid for a maximum of six months 22 and may be updated, replaced, or obsoleted by other documents at any 23 time. It is inappropriate to use Internet-Drafts as reference 24 material or to cite them other than as "work in progress." 26 The list of current Internet-Drafts can be accessed at 27 http://www.ietf.org/ietf/1id-abstracts.txt. 29 The list of Internet-Draft Shadow Directories can be accessed at 30 http://www.ietf.org/shadow.html. 32 This Internet-Draft will expire on January 18, 2006. 34 Copyright Notice 36 Copyright (C) The Internet Society (2005). 38 Abstract 40 This document defines the application of a set of protocols for 41 providing profile data to SIP user agents. The objective is to 42 define a means for automatically providing profile data a user agent 43 needs to be functional without user or administrative intervention. 44 The framework for discovery, delivery, notification and updates of 45 user agent profile data is defined here. As part of this framework a 46 new SIP event package is defined here for the notification of profile 47 changes. This framework is also intended to ease ongoing 48 administration and upgrading of large scale deployments of SIP user 49 agents. The contents and format of the profile data to be defined is 50 outside the scope of this document. 52 Table of Contents 54 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 55 2. Requirements Terminology . . . . . . . . . . . . . . . . . . 4 56 3. Profile Delivery Framework Terminology . . . . . . . . . . . 4 57 4. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 5 58 5. Use Cases . . . . . . . . . . . . . . . . . . . . . . . . . 7 59 5.1 Service Provider Use Case Scenario Bootstrapping with 60 Digest Authentication . . . . . . . . . . . . . . . . . . 7 61 5.2 Service Provider Use Case Scenario Bootstrapping with 62 Device Certificate . . . . . . . . . . . . . . . . . . . . 9 63 6. Data Model . . . . . . . . . . . . . . . . . . . . . . . . . 9 64 7. Profile Change Event Notification Package . . . . . . . . . 11 65 7.1 Event Package Name . . . . . . . . . . . . . . . . . . . . 11 66 7.2 Event Package Parameters . . . . . . . . . . . . . . . . . 11 67 7.3 SUBSCRIBE Bodies . . . . . . . . . . . . . . . . . . . . . 16 68 7.4 Subscription Duration . . . . . . . . . . . . . . . . . . 16 69 7.5 NOTIFY Bodies . . . . . . . . . . . . . . . . . . . . . . 17 70 7.6 Notifier processing of SUBSCRIBE requests . . . . . . . . 17 71 7.7 Notifier generation of NOTIFY requests . . . . . . . . . . 19 72 7.8 Subscriber processing of NOTIFY requests . . . . . . . . . 19 73 7.9 Handling of forked requests . . . . . . . . . . . . . . . 20 74 7.10 Rate of notifications . . . . . . . . . . . . . . . . . 20 75 7.11 State Agents . . . . . . . . . . . . . . . . . . . . . . 20 76 7.12 Examples . . . . . . . . . . . . . . . . . . . . . . . . 20 77 7.13 Use of URIs to Retrieve State . . . . . . . . . . . . . 21 78 7.13.1 Device URIs . . . . . . . . . . . . . . . . . . . . 22 79 7.13.2 User and Application URIs . . . . . . . . . . . . . 23 80 7.13.3 Local Network URIs . . . . . . . . . . . . . . . . . 24 81 8. Profile Delivery Framework Details . . . . . . . . . . . . . 24 82 8.1 Discovery of Subscription URI . . . . . . . . . . . . . . 24 83 8.1.1 Discovery of Local Network URI . . . . . . . . . . . . 25 84 8.1.2 Discovery of Device URI . . . . . . . . . . . . . . . 25 85 8.1.3 Discovery of User and Application URI . . . . . . . . 28 86 8.2 Enrollment with Profile Server . . . . . . . . . . . . . . 29 87 8.3 Notification of Profile Changes . . . . . . . . . . . . . 29 88 8.4 Retrieval of Profile Data . . . . . . . . . . . . . . . . 29 89 8.5 Upload of Profile Changes . . . . . . . . . . . . . . . . 30 90 8.6 Usage of XCAP with the Profile Package . . . . . . . . . . 30 91 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . 33 92 9.1 SIP Event Package . . . . . . . . . . . . . . . . . . . . 33 93 10. Security Considerations . . . . . . . . . . . . . . . . . . 33 94 10.1 Confidential Profile Content in NOTIFY Request . . . . . 34 95 10.2 Confidential Profile Content via Content Indirection . . 34 96 10.3 Integrity protection for non-confidential profiles . . . 36 98 11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 36 99 12. Change History . . . . . . . . . . . . . . . . . . . . . . . 36 100 12.1 Changes from 101 draft-ietf-sipping-config-framework-06.txt . . . . . . . 36 102 12.2 Changes from 103 draft-ietf-sipping-config-framework-05.txt . . . . . . . 37 104 12.3 Changes from 105 draft-ietf-sipping-config-framework-04.txt . . . . . . . 37 106 12.4 Changes from 107 draft-ietf-sipping-config-framework-03.txt . . . . . . . 38 108 12.5 Changes from 109 draft-ietf-sipping-config-framework-02.txt . . . . . . . 38 110 12.6 Changes from 111 draft-ietf-sipping-config-framework-01.txt . . . . . . . 38 112 12.7 Changes from 113 draft-ietf-sipping-config-framework-00.txt . . . . . . . 38 114 12.8 Changes from 115 draft-petrie-sipping-config-framework-00.txt . . . . . . 39 116 12.9 Changes from draft-petrie-sip-config-framework-01.txt . 39 117 12.10 Changes from draft-petrie-sip-config-framework-00.txt . 39 118 13. References . . . . . . . . . . . . . . . . . . . . . . . . . 40 119 13.1 Normative References . . . . . . . . . . . . . . . . . . 40 120 13.2 Informative References . . . . . . . . . . . . . . . . . 41 121 Author's Address . . . . . . . . . . . . . . . . . . . . . . 42 122 Intellectual Property and Copyright Statements . . . . . . . 43 124 1. Introduction 126 Today all SIP (Session Initiation Protocol) [RFC3261] user agent 127 implementers use proprietary means of delivering user, device, 128 application and local network policy profiles to the user agent. The 129 profile delivery framework defined in this document is intended to 130 enable a first phase migration to a standard means of providing 131 profiles to SIP user agents. It is expected that UA (User Agent) 132 implementers will be able to use this framework as a means of 133 delivering their existing proprietary data profiles (i.e. using their 134 existing proprietary binary or text formats). This in itself is a 135 tremendous advantage in that a SIP environment can use a single 136 profile delivery server for profile data to user agents from multiple 137 implementers. Follow-on standardization activities can: 138 1. define a standard profile content format framework (e.g. XML 139 with namespaces [W3C.REC-xml-names11-20040204] or name-value 140 pairs [RFC0822]). 141 2. specify the content (i.e. name the profile data parameters, xml 142 schema, name spaces) of the data profiles. 144 One of the objectives of the framework described in this document is 145 to provide a start up experience similar to that of users of an 146 analog telephone. When you plug in an analog telephone it just works 147 (assuming the line is live and the switch has been provisioned). 148 There is no end user configuration required to make analog phone 149 work, at least in a basic sense. So the objective here is to be able 150 to take a new SIP user agent out of the box, plug it in or install 151 the software and have it get its profiles without human intervention 152 other than security measures. This is necessary for cost effective 153 deployment of large numbers of user agents. 155 Another objective is to provide a scalable means for ongoing 156 administration of profiles. Administrators and users are likely to 157 want to make changes to profiles. 159 Additional requirements for the framework defined in this document 160 are described in: [I-D.ietf-sipping-ua-prof-framewk-reqs], 161 [I-D.sinnreich-sipdev-req] 163 2. Requirements Terminology 165 Keywords "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT" and 166 "MAY" that appear in this document are to be interpreted as described 167 in [RFC2119]. 169 3. Profile Delivery Framework Terminology 170 profile - data set specific to a user, device, user's application or 171 the local network. 172 device - software or hardware appliance containing one or more SIP 173 user agents. 174 profile content server - The server that provides the content of the 175 profiles using the protocol specified by the URI scheme. 176 notifier - As defined in [RFC3265] the SIP user agent server which 177 processes SUBSCRIBE requests for events and sends NOTIFY requests 178 with profile data or URIs (Uniform Resource Identifiers) that 179 point to the data. 180 profile delivery server - The logical collection of the notifier and 181 the server which provides the contents of the notification either 182 directly in the NOTIFY requests or indirectly via profile URI(s). 183 hotelling- when a user moves to a new user agent (i.e. that is not 184 already provisioned to know the user's identity, credentials or 185 profile data) and gives the user agent sufficient information to 186 retrieve the user's profile(s). The user agent either permanently 187 or temporarily makes the user's profiles effective on that user 188 agent. 189 roaming- when the user agent moves to a different local network 191 4. Overview 193 The profile life cycle can be described by five functional steps. 194 These steps are not necessarily discrete. However it is useful to 195 describe these steps as logically distinct. These steps are named as 196 follows: 198 Discovery - discover a profile delivery server 199 Enrollment - enroll with the profile delivery server 200 Profile Retrieval - retrieve profile data 201 Profile Change Notification - receive notification of profile changes 202 Profile Change Upload - upload profile data changes back to the 203 profile delivery server 205 Discovery is the process by which a UA finds the address and port at 206 which it enrolls with the profile delivery server. As there is no 207 single discovery mechanism which will work in all network 208 environments, a number of discovery mechanisms are defined with a 209 prescribed order in which the UA tries them until one succeeds. The 210 means of discovery is described in Section 8.1. 212 Enrollment is the process by which a UA makes itself known to the 213 profile delivery server. In enrolling, the UA provides identity 214 information, requested profile type(s) and supported protocols for 215 profile retrieval. It also subscribes to a mechanism for 216 notification of profile changes. As a result of enrollment, the UA 217 receives the data or the URI for each of the profiles that the 218 profile delivery server is able to provide. Each profile type (set) 219 requires a separate enrollment or SUBSCRIBE session. A profile type 220 may represent one or more data sets (e.g. one profile data set for 221 each of a user's applications). Enrollment which is performed by the 222 device by constructing and sending a SUBSCRIBE request to profile 223 delivery server for the event package described in Section 7. 225 Profile Retrieval is the process of retrieving the content for each 226 of the profiles the UA requested. The profiles are retrieved either 227 directly or indirectly from the NOTIFY request body as describe in 228 Section 7.5 and Section 8.4. 230 Profile Change Notification is the process by which the profile 231 delivery server notifies the UA that the content of one or more of 232 the profiles has changed. If the content is provided indirectly the 233 UA MAY retrieve the profile from the specified URI upon receipt of 234 the change notification. Profile change notification is provided by 235 the NOTIFY request for the event package as described in Section 7.8 236 and Section 8.3. 238 Profile Change Upload is the process by which a UA or other entity 239 (e.g. corporate directory or configuration management server) pushes 240 a change to the profile data back up to the profile delivery server. 241 This process is described in Section 8.5. 243 This framework defines a new SIP event package [RFC3265] to solve 244 enrollment and profile change notification steps. The event package 245 in Section 7 defines everything but the mandatory content type. This 246 makes this event package abstract until the content type is bound. 247 The profile content type(s) will be defined outside the scope of this 248 document. It is the author's belief that it would be a huge 249 accomplishment if all SIP user agents used this framework for 250 delivering their existing proprietary profiles. Even though this 251 does not accomplish interoperability of profiles, it is a big first 252 step in easing the administration of SIP user agents. The definition 253 of standard profiles and data sets (see [I-D.petrie-sipping-profile- 254 datasets] ) will enable interoperability as a subsequent step. 256 The question arises as to why SIP should be used for the profile 257 delivery framework. In this document SIP is used for only a small 258 portion of the framework. Other existing protocols are more 259 appropriate for transport of the profile contents (to and from the 260 user agent) and are suggested in this document. The discovery step 261 is simply a specified order and application of existing protocols 262 (see Section 8.1). SIP is only needed for the enrollment (see 263 Section 8.2) and change notification functionality (see Section 8.3) 264 of the profile delivery framework. In many SIP environments (e.g. 265 carrier/subscriber and multi-site enterprise) firewall, NAT (Network 266 Address Translation) and IP addressing issues make it difficult to 267 get messages between the profile delivery server and the user agent 268 requiring the profiles. 270 With SIP the users and devices already are assigned globally routable 271 addresses. In addition the firewall and NAT problems are already 272 presumably solved in the environments in which SIP user agents are to 273 be used. The local network profile (see Section 6, Section 7.13.3 274 and Section 8.1.1) provides the means to get firewall and NAT 275 traversal mechanism information to the device. Therefore SIP is the 276 best solution for allowing the user agent to enroll with the profile 277 delivery server, which may require traversal of multiple firewalls 278 and NATs. For the same reason the notification of profile changes is 279 best solved by SIP. It should be noted that this document is scoped 280 to providing profiles for devices which contain one or more SIP user 281 agents. This framework may be applied to non-SIP devices, however 282 more general requirements for non-SIP devices are beyond the scope of 283 this document. 285 The content delivery server may be either in the public network or 286 accessible through a private network. The user agents requiring 287 profiles may be behind firewalls and NATs and many protocols, such as 288 HTTP, may be used for profile content retrieval without special 289 consideration in the firewalls and NATs (e.g. an HTTP client on the 290 UA can typically pull content from a server outside the NAT/ 291 firewall.). 293 5. Use Cases 295 The following use case are intented to help give a understanding of 296 how the profile delivery framework can be used. These use cases are 297 not intended to be exhaustive in demonstrating all the capabilities 298 or ways the framework can be applied. 300 5.1 Service Provider Use Case Scenario Bootstrapping with Digest 301 Authentication 303 The following describes a use case scenario for bootstrapping a new 304 user agent, which has had no prior provisioned information, to the 305 point of being functional with a SIP Service Provider's system. In 306 this example scenario, the user has purchased a new SIP user agent. 307 The user signs up for the service to obtain three pieces of 308 information: a hostname, a user ID and a password. These three 309 pieces of information may be one-time use, that become invalid after 310 the one use. This scenario assumes that no association or mapping 311 between the device and the user's account is created before the 312 following steps: 314 1. The user plugs the device in to provide power and network 315 connectivity the first time (or installs the software in the case 316 of a software user agent). The device subscribes to the local 317 network to get the local network profile. However as the device 318 is plugged into a residential LAN or router, there is no profile 319 delivery server for the local network profile (see Section 8.1.1 320 and Section 7.13.3). The device assumes symmetric SIP signalling 321 as there is not local network profie which may have provided 322 other firewall or NAT traversal mechanism information. 323 2. The device prompts the user for the hostname to subscribe to for 324 the device profile. The hostname was provided by the service 325 provider and use as the host part of the SUBSCRIBE profile URI 326 described in Section 7.13.1. Note: in a scenario where the 327 system operator (e.g. enterprise) has control of the network, the 328 hostname for the SUBSCRIBE can be discovered (see Section 8.1.2) 329 to avoid the need for the user to enter the hostname. 330 3. The device creates a TLS connection for the SIP SUBSCRIBE request 331 to the provided hostname. The device verifies the server's 332 certificate. If the common name does not match the hostname or 333 the certificate is not valid, the device warns the user and 334 prompts whether to continue. 335 4. The profile delivery server receives the SUBSCRIBE request for 336 the device profile and sends a NOTIFY with content indirection 337 containing the HTTPS URI for the device profile (see 338 Section 7.5). 339 5. The device receives the NOTIFY request with the device profile 340 URI. The device prompts the user for the user ID and password 341 provided by the service provider. The device does an HTTPS GET 342 to retrieve the device profile (see Section 8.4 and Section 7.8). 343 The profile delivery server challenges for Digest authentication. 344 The device re-sends the HTTPS GET with Digest credentials using 345 the user ID and password entered by the user. Note: for devices 346 with only DTMF style input, the service provider may provide the 347 host, user ID and password in octal format that can be entered 348 requiring only digits. 349 6. The profile delivery server receives the HTTP GET request for the 350 device profile along with the user ID and password for the 351 specific user. At this point the profile delivery server has 352 authenticated the user and can create an association between a 353 specific device identified in the HTTPS URI and the user or user 354 account (see Section 10.2). The profile delivery server provides 355 the device profile which contains the on-going SUBSCRIBE request 356 URIs for the device, user and application profiles along with 357 credentials for retrieving the profiles. 358 7. The device receives the device profile from the HTTPS response, 359 re-SUBSCRIBEs using the device profile URI provided in the 360 profile. The device profile also may contain URIs for the 361 default user's user and application profile SUBSCRIBE request 362 URIs for the SIP event package defined in Section 7. The device 363 uses these URIs to retrieve user and application profiles in a 364 similar way to the device profile. After retriving these 365 profiles the device is fully functional in the service provider's 366 SIP service. 368 5.2 Service Provider Use Case Scenario Bootstrapping with Device 369 Certificate 371 The following describes another use case scenario where the device 372 implementor provides a certificate for the device which authenticates 373 the device ID. In this scenario, the user signs up for the SIP 374 service with the service provider and provides the device ID (see 375 Section 7.13.1 for more information on device ID) to the service 376 provider prior to the following steps, so that the service provider 377 has an association or mapping between the device ID and the user 378 account ahead of time. The service provide gives the user a hostname 379 to be entered on the device. 381 1. Step 1-3 occur the same as in the prior use case described in 382 Section 5.1. 383 2. The device receives the NOTIFY request with the device profile 384 URI. The device does an HTTPS GET to retrieve the device profile 385 (see Section 8.4 and Section 7.8). 386 3. The profile delivery server requests the device certficate in the 387 TLS connection used for the HTTPS GET. The device has a 388 certificate which has a SIP URI in the Subject Alternative Name 389 field that contains the device ID. The device certificate is 390 signed and provided by the implementor for the purpose of 391 authenticating the device ID in the initial bootstrapping process 392 only. The profile delivery server validates the device ID and 393 encrypts the device profile using the public key in the device's 394 certificate as described in Section 10.2 395 4. The device receives the encrypted device profile from the HTTPS 396 response, decrypts the profile using it private key. The process 397 continues in a similar way to step 6 in the above use case. The 398 device profile contains a more perminent device certificate and 399 private key or Digest authentication credentials which is used 400 for on-going device ID authentication. 402 6. Data Model 404 A conscious separation of device, user, application and local network 405 profiles is made in this document. This is useful to provide 406 features such as hotelling (described above) as well as securing or 407 restricting user agent functionality. By maintaining this 408 separation, a user may walk up to someone else's user agent and 409 direct that user agent to get the new user's profile data. In doing 410 so the user agent can replace the previous user's profile data while 411 still keeping the device's and the local network's profile data which 412 may be necessary for core functionality and communication described 413 in this document. The local network profiles are relevant to a 414 visiting device which gets plugged in to a foreign network. The 415 concept of the local network providing profile data is useful to 416 provide roaming (described above) as well as local policy data that 417 may constrain the user or device behavior relative to the local 418 network. For example media types and codecs may be constrained to 419 reflect the network's capabilities. 421 The separation of these profiles also enables the separation of the 422 management of the profiles. The user profile may be managed by a 423 profile delivery server operated by the user's ISP. The device 424 profile may be delivered from a profile delivery server operated by 425 the user's employer. The application profile(s) may be delivered 426 from the user's ASP (Application Service Provider). The local 427 network profile may delivered by a WLAN (Wireless LAN) hotspot 428 service provider. Some interesting services and mobility 429 applications are enabled with this separation of profiles. 431 A very high level data model is implied here with the separation of 432 these four profile types. Each profile type instance requires a 433 separate subscription to retrieve the profile. A loose hierarchy 434 exists mostly for the purpose of bootstrapping and discovery or 435 formation of the profile URIs. No other meaning is implied by this 436 hierarchy. However the profile format and data sets to be defined 437 outside this document may define additional meaning to this 438 hierarchy. In the bootstrapping scenario, a device straight out of 439 the box (software or hardware) does not know anything about its user 440 or local network. The one thing that is does know is it's instance 441 id. So the hierarchy of the profiles exists as follows. 443 The local network profile is subscribed to and retrieved based upon a 444 URI formed from the local network domain. The local network profile 445 is subscribed to first as it may contain information on how to 446 communicate to the Internet or primary network from the local network 447 (e.g. HTTP proxy, SIP firewall or NAT traversal information). The 448 device instance id is used to form the user id part of the URI for 449 subscribing to the device and local network profiles. The device 450 profile may contain a default user AOR (Address of Record) for that 451 device. The default user AOR may then be used to retrieve the user 452 profile. Applications to be used on the device may be defined in the 453 device and user profiles. The user's AOR is also used to retrieve 454 any application profiles for that user. 456 7. Profile Change Event Notification Package 458 This section defines a new SIP event package [RFC3265]. The purpose 459 of this event package is to send to subscribers notification of 460 content changes to the profile(s) of interest and to provide the 461 location of the profile(s) via content indirection [I-D.ietf-sip- 462 content-indirect-mech] or directly in the body of the NOTIFY. 463 Frequently the profiles delivered to the user agent are much larger 464 (e.g. several KB or even several MB) than the MTU of the network. 465 These larger profiles will cause larger than normal SIP messages and 466 consequently higher impact on the SIP servers and infrastructure. To 467 avoid the higher impact and load on the SIP infrastructure, content 468 indirection SHOULD be used if the profile is large enough to cause 469 packet fragmentation over the transport protocol. The presence of 470 the MIME type for content indirection [I-D.ietf-sip-content-indirect- 471 mech] in the Accept header indicates that the user agent supports 472 content indirection and that the profile delivery server SHOULD use 473 content indirection. Similarly the content type for the differential 474 notification of profile changes [I-D.ietf-simple-xcap-package] may be 475 used in the Accept header to express support for receiving profile 476 change deltas. 478 The MIME types or formats of profiles to be delivered via this 479 framework are to be defined in the documents that define the profile 480 contents. These profile MIME types specified in the Accept header 481 along with the profile types specified in the Event header parameter 482 "profile-type" MAY be used to specify which profiles get delivered 483 either directly or indirectly in the NOTIFY requests. As this event 484 package does not specify the mandatory content type, this package is 485 abstract. The profile definition documents will specify the 486 mandatory content type to make a concrete event package. 488 7.1 Event Package Name 490 The name of this package is "ua-profile". This value appears in the 491 Event header field present in SUBSCRIBE and NOTIFY requests for this 492 package as defined in [RFC3265]. 494 7.2 Event Package Parameters 496 This package defines the following new parameters for the event 497 header: "profile-type", "vendor", "model", "version", "effective-by", 498 "document", "auid", "network-user". The "effective-by" parameter is 499 for use in NOTIFY requests only. The "effective-by" parameter is 500 ignored if it appears in a SUBSCRIBE request. The other parameters 501 are for use in the SUBSCRIBE request and are ignored if they appear 502 in NOTIFY requests. 504 The "profile-type" parameter is used to indicate the token name of 505 the profile type the user agent wishes to obtain data or URIs for and 506 to be notified of subsequent changes. Using a token in this 507 parameter allows the URI semantics for retrieving the profiles to be 508 opaque to the subscribing user agent. All it needs to know is the 509 token value for this parameter. This document defines four logical 510 types of profiles and their token names. The contents or format of 511 the profiles is outside the scope of this document. 513 The four types of profiles defined here are "device", "user", 514 "application" and "local-network". Specifying "device" type 515 profile(s) indicates the desire for the profile data (URI when 516 content indirection is used) and change notification of the contents 517 of the profile that is specific to the device or user agent. 518 Specifying "user" type profile indicates the desire for the profile 519 data (URI when content indirection is used) and change notification 520 of the profile content for the user. Specifying "application" type 521 profile indicates the desire for the profile data (URI when content 522 indirection is used) and change notification of the profile content 523 for the user's applications. Specifying "local-network" type profile 524 indicates the desire for profile data (URI when content indirection 525 is used) specific to the local network. The device, user, 526 application or local network is identified in the URI of the 527 SUBSCRIBE request. A separate SUBSCRIBE dialog is used for each 528 profile type. The profile type associated with the dialog can then 529 be used to infer which profile type changed and is contained in the 530 NOTIFY or content indirection URI. The Accept header of the 531 SUBSCRIBE request MUST include the MIME types for all profile content 532 types for which the subscribing user agent wishes to retrieve 533 profiles or receive change notifications. In the following ABNF, 534 EQUAL and token are defined in [RFC3261]. 536 Profile-type = "profile-type" EQUAL profile-value 537 profile-value = profile-types / token 538 profile-types = "device" / "user" / "application" / "local-network" 540 The "device", "user", "application" or "local-network" token in 541 the profile-type parameter may represent a class or set of profile 542 properties. As standards are defined for specific profile 543 contents related to the user, device or local network, it may be 544 desirable to define additional tokens for the profile-type 545 parameter. Also additional content types may be defined along 546 with the profile formats that can be used in the Accept header of 547 the SUBSCRIBE to filter or indicate what data sets of the profile 548 are desired. 550 The rational for the separation of user, device, application and 551 local network type profiles is provided in Section 4. It should be 552 noted that any of the types may result in zero or more profiles or 553 URIs being provided in the NOTIFY request. As discussed, a default 554 user may be assigned to a device. The default user's AOR, if defined 555 in the device profile, may in turn be used as the URI to SUBSCRIBE to 556 the "user" and "application" profile types. 558 The data provided in the four types of profiles may overlap. As an 559 example the codecs that a user prefers to use, the codecs that the 560 device supports (and the enterprise or device owner wishes to use), 561 the codecs that the local network can support (and the network 562 operator wishes to allow) all may overlap in how they are specified 563 in the three corresponding profiles. This policy for merging the 564 constraints across the multiple profile types can only unambiguously 565 be defined in the context of the profile syntax and semantics. This 566 is out of scope for this document. 568 The "vendor", "model" and "version" parameter values are tokens 569 specified by the implementer of the user agent. These parameters 570 MUST be provided in the SUBSCRIBE request for all profile types. The 571 implementer SHOULD use their DNS domain name (e.g. example.com) as 572 the value of the "vendor" parameter so that it is known to be unique. 573 These parameters are useful to the profile delivery server to affect 574 the profiles provided. In some scenarios it is desirable to provide 575 different profiles based upon these parameters. For example feature 576 property X in a profile may work differently on two versions of user 577 agent. This gives the profile delivery server the ability to 578 compensate for or take advantage of the differences. In the 579 following ABNF, EQUAL and quoted-string are defined in [RFC3261]. 581 Vendor = "vendor" EQUAL quoted-string 582 Model = "model" EQUAL quoted-string 583 Version = "version" EQUAL quoted-string 585 The "network-user" parameter SHOULD be set when subscribing for 586 device and local network profiles if the user's AOR is known. When 587 the profile-type is "device" or "local-network", the SUBSCRIBE URI 588 addresses the device or local network profile delivery server. It by 589 design cannot indicate the user's identity. The "network-user" 590 parameter is used to indicate the user's AOR. The SUBSCRIBE server 591 SHOULD authenticate the subscriber to verify the AOR in the "network- 592 user" parameter if the profile provided is specific to the AOR. If 593 the value of the "profile-type" parameter is not "device" or "local- 594 network", the "network-user" parameter has no defined meaning and is 595 ignored. If the "network-user" parameter is provided in the 596 SUBSCRIBE request, it MUST be present in the NOTIFY request as well. 597 In the following ABNF, name-addr, addr-spec are defined in [RFC3261]. 599 Network-User = "network-user" EQUAL name-addr / addr-spec 600 When the profile-type is "device", the user agent SHOULD set the 601 "network-user" parameter to the user's AOR if it is known. This is 602 an indication to the profile delivery server to set or change the 603 association of the default user with the device indicated in the 604 SUBSCRIBE URI. If the profile delivery server implements and allows 605 this policy of setting the default user with a device, the user agent 606 can utilize this mechanism to allow a user to login and make the user 607 agent and user association permanent. 609 In the case where the profile-type is "local-network", the user agent 610 SHOULD set the "network-user" parameter if the user's AOR is known. 611 If the user has special privileges beyond that of an anonymous user 612 in the local network, the "network-user" parameter identifies the 613 user to the local network. The value of this parameter is the user's 614 address of record. 616 The "effective-by" parameter in the Event header of the NOTIFY 617 request specifies the maximum number of seconds before the user agent 618 must attempt to make the new profile effective. The "effective-by" 619 parameter MAY be provided in the NOTIFY request for any of the 620 profile types. A value of 0 (zero) indicates that the subscribing 621 user agent must attempt to make the profiles effective immediately 622 (despite possible service interruptions). This gives the profile 623 delivery server the power to control when the profile is effective. 624 This may be important to resolve an emergency problem or disable a 625 user agent immediately. The "effective-by" parameter is ignored in 626 all messages other than the NOTIFY request. In the following ABNF, 627 EQUAL and DIGIT are defined in [RFC3261]. 629 Effective-By = "effective-by" EQUAL 1*DIGIT 631 The "document" parameter is used to specify a relative URI for a 632 specific profile document that the user agent wishes to retrieve and 633 for which it wishes to receive change notification. This is useful 634 for profile content like XCAP [I-D.ietf-simple-xcap] where there is a 635 well defined URI schema and the user agent knows the specific content 636 that it wants. This provides a filtering mechanism to restrict the 637 content to be retrieved and for which change notification is to be 638 received. (The size of the content is important in limited bandwidth 639 environments.) The "document" parameter value syntax is a quoted 640 string. The values for the "document" parameter are defined as part 641 of the profile data format, which is out of scope for this document. 642 To use the "document" parameter, the profile data format, must also 643 define a URL path schema. For more details on the use of this 644 package and the "document" parameter with XCAP see Section 8.6. The 645 "document" parameter MAY be set in SUBSCRIBE requests for any of the 646 profile types. It is ignored in all other messages. In the 647 following ABNF EQUAL and quoted-string is defined in [RFC3261]. 649 Document = "document" EQUAL quoted-string 651 The "auid" parameter MAY be set when the "profile-type" parameter 652 value is "application". The "auid" indicates that the user agent 653 wishes to retrieve the profile data or URI and change notification 654 for the application profile data for the specific application 655 indicated in the value of the "auid" parameter. Like the "document" 656 parameter, the "auid" parameter provides a filtering mechanism on the 657 profile content. The "auid" parameter value is a quoted string. The 658 values for the "auid" parameter are defined as part of the profile 659 data format to be used with XCAP (see [I-D.ietf-simple-xcap] ), which 660 is out of scope for this document. The "auid" parameter has meaning 661 only in SUBSCRIBE requests when the "profile-type" Event header 662 parameter is set to "application". It is an error to set both the 663 "document" and "auid" parameters in a SUBSCRIBE request. The "auid" 664 parameter is ignored in all other messages. 666 AUID = "auid" EQUAL quoted-string 668 SUBSCRIBE request Event header examples: 669 Event: ua-profile;profile-type=device; 670 vendor="vendor.example.com";model="Z100";version="1.2.3" 672 Event: ua-profile;profile-type="user"; 673 document="user-aor/"; 674 vendor="premier";model="trs8000";version="5.5" 676 NOTIFY request Event header examples: 677 Event: ua-profile;effective-by=0 679 Event: ua-profile;effective-by=3600 681 The following table shows the use of Event header parameters in 682 SUBSCRIBE requests for the four profile types: 684 profile-type || device | user | application | local-network 685 =========================================================== 686 vendor || m | m | m | m 687 model || m | m | m | m 688 version || m | m | m | m 689 network-user || | | | s 690 document || o | o | o | o 691 auid || | | o | 692 effective-by || | | | 694 m - manditory 695 s - SHOULD be provided 696 o - optional 697 Non-specified means that the parameter has no meaning and 698 should be ignored. 700 The following table shows the use of Event header parameters in 701 NOTIFY requests for the four profile types: 703 profile-type || device | user | application | local-network 704 =========================================================== 705 vendor || | | | 706 model || | | | 707 version || | | | 708 network-user || | | | s 709 document || o/m | o/m | o/m | o/m 710 auid || | | o/m | 711 effective-by || o | o | o | o 713 o/m - manditory if provided in the SUBSCRIBE request 715 7.3 SUBSCRIBE Bodies 717 This package defines no new use of the SUBSCRIBE request body. 718 Future documents may specify a filter-like mechanism using etags to 719 minimize the delivery or notification of profiles where the user 720 agent already has a current version. 722 7.4 Subscription Duration 724 As the presence (or lack of) a device or user agent is not very time 725 critical to the functionality of the profile delivery server, it is 726 recommended that default subscription duration be 86400 seconds (one 727 day). A one-time fetch of a profile can be accomplished by setting 728 the Expires parameter to 0 as defined in [RFC3265] resulting in a 729 single NOTIFY with no change notification. 731 7.5 NOTIFY Bodies 733 The size of profile content is likely to be hundreds to several 734 thousand of bytes in size. For this reason if the Accept header of 735 the SUBSCRIBE included the MIME type message/external-body indicating 736 support for content indirection the profile delivery server SHOULD 737 use content indirection [I-D.ietf-sip-content-indirect-mech] in the 738 NOTIFY body for providing the profiles. 740 When delivering profiles via content indirection the profile delivery 741 server MUST include the Content-ID MIME header described in 742 [I-D.ietf-sip-content-indirect-mech] for each profile URI. This is 743 to avoid unnecessary download of the profiles. Some user agents are 744 not able to make a profile effective without rebooting or restarting. 745 Rebooting is something to be avoided on a user agent performing 746 services such as telephony. In this way the Content-ID allows the 747 user agent to avoid unnecessary interruption of service as well. The 748 Content-Type MUST be specified for each URI. For minimal 749 interoperability, the profile delivery server MUST support the 750 "http:" and "https:" URI schemes for content indirection. Other URI 751 schemes MAY also be provided in the content indirection. However the 752 security considerations are define for content indirection using HTTP 753 and HTTPS. Other protocols MAY be supported for content indirection, 754 but are out of scope of this document. 756 Initially user agent implementers may use a proprietary content 757 type for the profiles retrieved from the URI(s). This is a good 758 first step towards easing the management of user agents. Standard 759 profile contents, content type and formats will need to be defined 760 for true interoperability of profile delivery. The specification 761 of the content is out of the scope of this document. 763 The URI scheme [RFC2396] used in content indirection may be dictated 764 by the profile content that is required. It is expected that FTP 765 [RFC0959], HTTP [RFC2616], HTTPS [RFC2818], LDAP [RFC3377], XCAP 766 [I-D.ietf-simple-xcap] and other URI schemes could be used by this 767 package and framework if the subscribing user agent and profile 768 delivery server both support the same scheme. The negotiation of the 769 URI scheme is described in the following sections. 771 7.6 Notifier processing of SUBSCRIBE requests 773 The general rules for processing SUBSCRIBE requests [RFC3265] apply 774 to this package. If content indirection is used for delivering the 775 profiles, the notifier does not need to authenticate the subscription 776 as the profile content is not transported in the SUBSCRIBE or NOTIFY 777 transaction messages. With content indirection only URIs are 778 transported in the NOTIFY request which may be secured using the 779 techniques in Section 10. If content indirection is not used, the 780 subscribe server SHOULD reject SUBSCRIBE requests from conections 781 that are not over TLS and SHOULD challenge the SUBSCRIBE request with 782 SIP Digest authentication. The subscriber MUST support the "http:" 783 or "https:" URI scheme for content indirection. If the subscriber 784 wishes to use a URI scheme other than "http:", the subscriber must 785 use the "schemes" Contact header field parameter to indicate the URI 786 scheme as defined in [I-D.ietf-sip-content-indirect-mech]. For 787 example the subscriber may request that content indirection use the 788 "ldaps:" URI scheme by including "ldaps" in the "scheme" Contact 789 header parameter of the SUBSCRIBE request. If the subscriber does 790 not specify the URI scheme, the notifier may use either "http:" or 791 "https:". 793 The profile generation behavior of the profile delivery server is 794 left to the implementer. The profile delivery server may be as 795 simple as a SIP SUBSCRIBE UAS and NOTIFY UAC front end to a simple 796 HTTP server delivering static files that are hand edited. At the 797 other extreme the profile delivery server can be part of a 798 configuration management system that integrates with a corporate 799 directory and IT system or carrier operations support systems, 800 where the profiles are automatically generated. The design of 801 this framework intentionally provides the flexibility of 802 implementation from simple/cheap to complex/expensive. 804 If the user or device is not known to the profile delivery server, 805 the implementer MAY accept the subscription or reject it. It is 806 recommended that the implementer accept the subscription. It is 807 useful for the profile delivery server to maintain the subscription 808 for unprovisioned users or devices as an administrator may add the 809 user or device to the system after the initial subscription, defining 810 the profile contents. This allows the profile delivery server to 811 immediately send a NOTIFY request with the profile URIs. If the 812 profile delivery server does not accept the subscription from an 813 unknown user or device, the administer or user must manually provoke 814 the user agent to re-subscribe. This may be difficult if the user 815 agent and administrator are at different locations. 817 A user agent can provide hotelling by collecting a user's AOR and 818 credentials needed to SUBSCRIBE and retrieve the user's profiles. 819 Hotelling functionality is achieved by subscribing to the user's AOR 820 and specifying the "user" profile type. This same mechanism can also 821 be used to secure a user agent, requiring a non-mobile user to login 822 to enable functionality beyond the default user's restricted 823 functionality. 825 When the Event header "profile-type" is "device" and the user agent 826 has provided the user's AOR in the "network-user" parameter, the 827 profile delivery server MAY set or change the default user associated 828 with the device indicated in the SUBSCRIBE URI. This is an 829 implementation or policy decision. The profile delivery server 830 SHOULD authenticate the user for the SUBSCRIBE request before 831 changing the default user associated with the device. 833 7.7 Notifier generation of NOTIFY requests 835 As in [RFC3265], the profile delivery server MUST always send a 836 NOTIFY request upon accepting a subscription. If the device or user 837 is unknown to the profile delivery server and it chooses to accept 838 the subscription, the implementer has two choices. A NOTIFY MAY be 839 sent with no body or content indirection containing the profile 840 URI(s). Alternatively a NOTIFY MAY be sent with a body or content 841 indirection containing URI(s) pointing to a default data set. The 842 data sets provided may allow for only limited functionality of the 843 user agent (e.g. for a user agent with telephony capabilities, to 844 enable calls to help desk and emergency services.). This is an 845 implementation and business policy decision for the profile delivery 846 server. 848 If the URI in the SUBSCRIBE request is a known identity and is 849 provisioned with the requested profile type (i.e. as specified in the 850 profile-type parameter of the Event header), the profile delivery 851 server SHOULD send a NOTIFY with profile data or content indirection 852 (if the content indirection mime type was included in the Accept 853 header) containing the URI for the profile. To protect the integrety 854 of the profile data or indirect content profile data URIs, the 855 notifier SHOULD send the NOTIFY request on the same TLS connection as 856 the SUBSCRIBE request came in on if TLS was used. 858 The profile delivery server may specify when the new profiles must be 859 made effective by the user agent. The profile delivery server MAY 860 specify a maximum time in seconds (zero or more), in the 861 "effective-by" event header parameter, by which the user agent is 862 required to make the new profiles effective for all dialogs. 864 7.8 Subscriber processing of NOTIFY requests 866 The user agent subscribing to this event package MUST adhere to the 867 NOTIFY request processing behavior specified in [RFC3265]. The user 868 agent MUST attempt to make the profiles effective within the time in 869 seconds given in the "effective-by" Event header parameter if present 870 in the NOTIFY request (see Section 7.7). By default the user agent 871 makes the profiles effective as soon as it thinks that it is non- 872 obtrusive to do so (e.g. when there are no active calls). Profile 873 changes SHOULD affect behavior on all new dialogs which are created 874 after the notification, but may not be able to affect existing 875 dialogs. The user agent SHOULD use one of the techniques specified 876 in Section 10 to securely retrieve the profiles. If the subscriber 877 included the MIME type message/external-body for content indirection 878 in the SUBSCRIBE request Accept header, the subscriber MUST support 879 the http: or https: URI schemes for content indirection. If the 880 subscriber indicated alternative URI schemes for content indirection 881 it MUST also indicate support for http: or https:. The subscriber 882 should still be prepared to use http: or https: as the profile 883 delivery server may not support the alternative URI schemes. 885 7.9 Handling of forked requests 887 This event package allows the creation of only one dialog as a result 888 of an initial SUBSCRIBE request. The techniques to achieve this are 889 described in section 4.4.9 of [RFC3265]. 891 7.10 Rate of notifications 893 It is anticipated that the rate of change for user and device 894 profiles will be very infrequent (i.e. days or weeks apart). For 895 this reason no throttling or minimum period between NOTIFY requests 896 is specified for this package. 898 7.11 State Agents 900 State agents are not applicable to this event package. 902 7.12 Examples 904 Example SUBSCRIBE and NOTIFY request using content indirection: 906 SUBSCRIBE sip:MAC%3aFF00000036C5@acme.example.com SIP/2.0 907 Event: ua-profile;profile-type=device;vendor="vendor.example.com"; 908 model="Z100";version="1.2.3" 909 From: sip:MAC%3aFF00000036C5@acme.example.com;tag=1234 910 To: sip:MAC%3aFF00000036C5@acme.example.com;tag=abcd 911 Call-ID: 3573853342923422@10.1.1.44 912 CSeq: 2131 SUBSCRIBE 913 Contact: sip:MAC%3aFF00000036C5@10.1.1.44 914 Via: SIP/2.0/TCP 10.1.1.41; 915 branch=z9hG4bK6d6d35b6e2a203104d97211a3d18f57a 916 Accept: message/external-body, application/z100-device-profile 917 Content-Length: 0 919 NOTIFY sip:MAC%3aFF00000036C5@10.1.1.44 SIP/2.0 920 Event: ua-profile;effective-by=3600 921 From: sip:MAC%3aFF00000036C5@acme.example.com;tag=abcd 922 To: sip:MAC%3aFF00000036C5@acme.example.com;tag=1234 923 Call-ID: 3573853342923422@10.1.1.44 924 CSeq: 321 NOTIFY 925 Via: SIP/2.0/UDP 192.168.0.3; 926 branch=z9hG4bK1e3effada91dc37fd5a0c95cbf6767d1 927 MIME-Version: 1.0 928 Content-Type: multipart/mixed; boundary=boundary42 929 Content-Length: ... 931 --boundary42 932 Content-Type: message/external-body; 933 access-type="URL"; 934 expiration="Mon, 24 June 2002 09:00:00 GMT"; 935 URL="http://www.example.com/devices/ff00000036c5"; 936 size=1234 938 Content-Type: application/z100-device-profile 939 Content-ID: <39EHF78SA@example.com> 941 --boundary42-- 943 7.13 Use of URIs to Retrieve State 945 The URI for the SUBSCRIBE request is formed differently depending 946 upon which profile type the subscription is for. This allows the 947 different profile types to be potentially managed by different 948 profile delivery servers (perhaps even operated by different 949 entities). 951 7.13.1 Device URIs 953 The URI for the "device" type profile (device URI) is based upon the 954 identity of the device. The device URI MUST be unique across all 955 devices and implementations. If an instance id is used as the user 956 part of the device URI, it SHOULD remain the same for the lifetime of 957 the user agent. The device URI is used to identify which profile is 958 associated with a specific instance of a user agent. 960 If the user agent changed its device URI, the profile delivery 961 server would not know the association between the profile and the 962 device. This would also make it difficult for the profile 963 delivery server to track user agents under profile management. 964 The profile delivery server may decide to provide the same device 965 profile to all devices of the same vendor, model and version. 966 However this is a implementation choice of the profile delivery 967 server. The subscribing device has no way of knowing whether the 968 profiles for each device are different. For this reason the 969 device must always use a unique id in the device SUBSCRIBE request 970 URI. As an example the device profile for similar devices may 971 differ with properties such as the default user. This is how the 972 bootstrapping mechanism works as described in Section 8.1.3. 974 The URI for the device type profile MUST use a unique identifier as 975 the user portion of the URI. The host and port portion of the URI is 976 set to that of the domain or address of the profile delivery server 977 which manages that user agent. A means of discovering the host and 978 port portion is discussed in Section 8.1. There is an administration 979 aspect of the unique identifier, that makes it desirable for the id 980 to be obtainable or predictable prior to installation of the device 981 (hard or soft). Also from a human factors perspective, ids that are 982 easily distinguished and communicated will make the administrators 983 job a little easier. The MAC address or UUID SHOULD be used for 984 constructing a unique identifier to be used in the user portion of 985 the device URI. 987 If the identifier is a MAC address, it MUST be formatted as the 988 letters "MAC:" followed by a 12 digit hexadecimal representation of 989 the MAC address. The address can not include ":", whitespace, or 990 other formatting. 991 The MAC address of the device may be used if there will always be 992 no more than one user agent using that MAC address over time (e.g. 993 a dedicated telephone appliance). The MAC address may not be used 994 if more than one user agent instance exists using the same MAC 995 address (e.g. multiple instances of a softphone may run on a 996 general purpose computing device). The advantage of the MAC 997 address is that many vendors put bar codes on the device with the 998 actual MAC address on it. A bar code scanner is a convenient 999 means of collecting the instance id for input and provisioning on 1000 the profile delivery server. If the MAC address is used, it is 1001 recommended that the MAC address is rendered in all upper case 1002 with no punctuation for consistency across implementations. A 1003 prefix of "MAC:" should be added to the MAC address to form a 1004 proper URN [RFC2141]. For example a device managed by 1005 sipuaconfig.example.com using its MAC address to form the device 1006 URI might look like: 1007 sip:MAC%3a00DF1E004CD0@sipuaconfig.example.com. 1009 UHEX = DIGIT / %x41-46 ;uppercase A-F 1010 MAC = %x4d.41.43 ; MAC in caps 1011 mac-ident = MAC ":" 12UHEX 1013 When the MAC address is not used in the device URI, UUID SHOULD be 1014 used. 1016 For devices where there is no MAC address or the MAC address is 1017 not unique to an instance of a user agent (e.g. multiple 1018 softphones on a computer or a gateway with multiple logical user 1019 agents) it is recommended that a UUID is used as the user portion 1020 of the device URI. The same approach to defining a user agent 1021 instance ID as [I-D.ietf-sip-gruu] should be used. When 1022 constructing the instance id the implementer should also consider 1023 that a human may need to manually enter the instance id to 1024 provision the device in the profile delivery server (e.g. longer 1025 strings are more error prone in data entry). When the URN is used 1026 as the user part of URI, it MUST be URL escaped. The ":" is not a 1027 legal character (without being escaped) in the user part of a 1028 name-addr. For example the instance ID: 1029 urn:uuid:f81d4fae-7ced-11d0-a765-00a0c91e6bf6 would be escaped to 1030 look as follows in a URI: 1031 sip:urn%3auuid%3af81d4fae-7ced-11d0-a765-00a0c91e6bf6@example.com. 1032 Soft user agents are likely to need to use this approach due to 1033 the multi-user nature of general purpose computers. The software 1034 installer program might generate the uuid as part of the install 1035 process so that it remains persistent for the installation. It 1036 may also be desirable that any upgrades of the software maintain 1037 the unique id. However these are all implementation choices. 1039 7.13.2 User and Application URIs 1041 The URI for the "user" and "application" type profiles is based upon 1042 the identity of the user. The user's address of record (AOR) is used 1043 as the URI in the SUBSCRIBE request. A new user agent or device may 1044 not know the user's AOR. The user's AOR may be obtained as part of a 1045 default user property in the device profile. Alternatively the user 1046 agent may prompt the user for an AOR and credentials to be used to 1047 authenticate the request. This can provide a login and/or hotelling 1048 feature on the user agent. The user agent may be pre-provisioned 1049 with the user's AOR or provided as information on a SIM or flash key. 1050 These are only examples not an exhaustive list of sources for the 1051 user AOR. 1053 7.13.3 Local Network URIs 1055 The URI for the "local-network" type profile is based upon the 1056 identity of the local network. When subscribing to the local network 1057 profile, the user part of the URI SHOULD be the same device ID used 1058 as the user part of the device profile SUBSCRIBE request URI defined 1059 in Section 7.13.1. The host and port part of the URI is the local 1060 network name/domain. The discovery of the local network name or 1061 domain is discussed in Section 8.1. The user agent may provide the 1062 user's AOR as the value to the "network-user" event header parameter. 1063 This is useful if the user has privileges in the local network beyond 1064 those of the default user. When "network-user" is provided the 1065 profile delivery server SHOULD authenticate the user before providing 1066 the profile if additional privileges are granted. Example URI: 1067 sip:MAC%3a00DF1E004CD0@example.com 1069 The local network profile SUBSCRIBE request URI uses the device ID 1070 in the user part of the local network request URI so that every 1071 device in the network has a unique and constant request URI. Even 1072 though every device may get the same or similar local network 1073 profiles, the uniqueness of the URI provides an important 1074 capability. Having unique URIs allows the management of the local 1075 network to track user agents present in the network and 1076 consequently also manage resources such as bandwidth and port 1077 allocation. 1079 8. Profile Delivery Framework Details 1081 The following describes how different functional steps of the profile 1082 delivery framework work. Also described here is how the event 1083 package defined in this document provides the enrollment and 1084 notification functions within the framework. 1086 8.1 Discovery of Subscription URI 1088 The discovery approach varies depending upon which profile type URI 1089 is to be discovered. The order of discovery is important in the 1090 bootstrapping situation as the user agent may not have any 1091 information provisioned. The local network profile should be 1092 discovered first as it may contain key information such as how to 1093 traverse a NAT/firewall to get to outside services (e.g. the user's 1094 profile delivery server). The device profile URI should be 1095 discovered next. The device profile may contain the default user's 1096 AOR or firmware/software information that should be updated first 1097 before proceeding with the discovery process. The user and 1098 application profile subscription URIs should be discovered last. The 1099 URIs are formed differently for each of the profile types. This is 1100 to support the delegation of the profile management to potentially 1101 four different entities. However all four profile types may be 1102 provided by the same entity. As the user agent has no way of knowing 1103 whether the profiles are provide by one or more different profile 1104 delivery servers ahead of time, it must subscribe to all four profile 1105 types in separate SUBSCRIBE requests to get the profiles. 1107 8.1.1 Discovery of Local Network URI 1109 The "discovered" host for the "local-network" profile subscription 1110 URI is the local IP network domain for the user agent, either 1111 provisioned as part of the device's static network configuration or 1112 discovered via DHCP. The local network profile subscription URI 1113 SHOULD not be remembered if the user agent moves from one local 1114 network to another other. The user agent should perform the local 1115 network discovery to construct the network profile subscription 1116 request URI every time it starts up or network connectivity is 1117 regained. 1119 For example: The user agent requested and received the local 1120 domain name via DHCP: airport.example.net. If the device ID is: 1121 MAC:00DF1E004CD0, the local network profile SUBSCRIBE request URI 1122 would look like: sip:MAC%3a00DF1E004CD0@airport.example.net. The 1123 user agent should send this request using the normal SIP locating 1124 mechanisms defined in [RFC3263]. The Event header would look like 1125 the following if the user agent decided to provide 1126 sip:alice@example.com as the user's AOR. (Alice may have a prior 1127 arrangement with the local network operator giving her special 1128 privileges.): 1130 Event: ua-profile;profile-type=local-network; 1131 network-user="sip:alice@example.com" 1133 8.1.2 Discovery of Device URI 1135 The discovery function is needed to bootstrap user agents to the 1136 point of knowing where to enroll with the profile delivery server. 1137 Section 7.13.1 describes how to form the user part of the device 1138 profile SUBSCRIBE request URI used for enrollment. However the 1139 bootstrapping problem for the user agent (out of the box) is what to 1140 use for the host and port in the device URI. Due to the wide 1141 variation of environments in which the enrolling user agent may 1142 reside (e.g. behind residential router, enterprise LAN, WLAN hotspot, 1143 ISP, dialup modem) and the limited control that the administrator of 1144 the profile delivery server (e.g. enterprise, service provider) may 1145 have over that environment, no single discovery mechanism works 1146 everywhere. 1148 Therefore a number of mechanisms should be tried in the specified 1149 order: SIP DHCP option [RFC3361], SIP DNS SRV [RFC3263], DNS A record 1150 and manual. The user agent may be pre-provisioned with the host and 1151 port (e.g. service providers may pre-provision a device before 1152 sending it to a subscriber, provide a SIM or flash key, etc.) in 1153 which case this discovery mechanism is not needed. Before performing 1154 the discovery steps, the user agent should provide a means to skip 1155 the discovery stage and manually enter the device URI host and port. 1156 In addition the user agent should allow the user to accept or reject 1157 the discovered host and port, in case an alternate to the discovered 1158 host and port are desired. 1160 1. The first discovery mechanism that should be tried to construct 1161 the device SUBSCRIBE request URI, as described in Section 7.13.1, 1162 is to use the host and port of the outbound proxy discovered by 1163 the SIP DHCP option as described in [RFC3361]. If the SIP DHCP 1164 option is not provided in the DHCP response; or no SIP response 1165 is received for the SUBSCRIBE request; or a SIP failure response 1166 other than for authorization is received for the SUBSCRIBE 1167 request to the ua-profile event, the next discovery mechanism 1168 should be tried. 1170 For example: Consider a dedicated hardware device with a 1171 single user agent having the MAC address: abc123efd456. The 1172 user agent sends a DHCP request including the request for the 1173 DHCP option for SIP: 120 (see [RFC3361]). If the DHCP 1174 response includes an answer for option 120, then the DNS name 1175 or IP address included is used in the host part of the device 1176 URI. For this example let's assume: example.com. The device 1177 URI would look like: sip:MAC%3aABC123EFD456@example.com. The 1178 user agent should send this request using the normal SIP 1179 locating mechanisms defined in [RFC3263]. If the response 1180 fails then, the next discovery mechanism is tried. 1182 2. The local IP network domain for the user agent, either configured 1183 or discovered via DHCP, should be used with the technique in 1184 [RFC3263] to obtain a host and port to use in the SUBSCRIBE URI. 1185 If no SIP response or a SIP failure response other than for 1186 authorization is received for the SUBSCRIBE request to the ua- 1187 profile event, the next discovery mechanism should be tried. 1189 For example: The user agent requested and received the local 1190 domain name (option 15) in the DHCP response: 1191 boston.example.com. The device URI would look like: 1192 sip:MAC%3aABC123EFD456@boston.example.com. The user agent 1193 should send this request using the normal SIP locating 1194 mechanisms defined in [RFC3263]. If the response fails then, 1195 the next discovery mechanism is tried. 1197 3. The fully qualified host name constructed by concatenating 1198 "sipuaconfig" and the local IP network domain (as provided via 1199 DHCP or provisioned) should be tried next using the technique in 1200 [RFC3263] to obtain a host and port to use in the SUBSCRIBE URI. 1201 If no SIP response or a SIP failure response other than for 1202 authorization is received for the SUBSCRIBE request to the ua- 1203 profile event, the next discovery mechanism should be tried. 1205 For example: The user agent requested and received the local 1206 domain name via DHCP as in the above example: 1207 boston.example.com. The device URI would look like: 1208 sip:MAC%3aABC123EFD456@sipuaconfig.boston.example.com. The 1209 user agent should send this request using the normal SIP 1210 locating mechanisms defined in [RFC3263]. If the response 1211 fails then, the next discovery mechanism is tried. 1213 4. If all other discovery techniques fail, a manual means for the 1214 user to enter the host and port used to construct the SUBSCRIBE 1215 request URI MUST be provided by the user agent. 1217 Two approaches to the manual discovery process are suggested. In the 1218 first approach using SIP, the user agent provides a means for 1219 entering the subscription host and port information for the request 1220 URI along with the user id and password to be used for authentication 1221 of the SUBSCRIBE request. With this approach the user agent begins 1222 with the enrollment process followed by the change notification and 1223 profile retrieve steps. 1225 An alternative to the manual discovery using SIP, is to start with 1226 the retrieve process. The user agent provides a means of entering a 1227 HTTPS URI along with the user id and password to be used for 1228 authentication of the retrieval of the profile. The retrieved device 1229 profile may contain the properties for the SUBSCRIBE request URI and 1230 credentials to enroll and get change notification of profile changes. 1231 This approach bootstraps the process in a different step in the 1232 cycle, but uses the same profile framework. When the device starts 1233 with retrieval of the profile via HTTPS (instead of a SIP SUBSCRIBE 1234 to the event package), the device MUST provide the Event header in 1235 the HTTPS request using the same format as described for the 1236 SUBSCRIBE request (see Section 7.2) . The Event header is necessary 1237 to determine which profile is requested as well as for providing 1238 specific information about the device. 1240 Once a user agent has successfully discovered, enrolled and received 1241 a NOTIFY response with profile data or URI(s), the user agent should 1242 cache (i.e. store persistantly) the device profile SUBSCRIBE request 1243 URI (rather than reconstructing it as described in the discovery 1244 process every time the device is restarted) to avoid having to 1245 rediscover the profile delivery server again in the future. Caching 1246 of the device URI is necessary when the user agent is likely to move 1247 to different local network domains as the local network may not be 1248 the provider for the device's profile. The user agent should not 1249 cache the device URI until it receives a NOTIFY with profile data or 1250 URI(s). The reason for this is that a profile delivery server may 1251 send 202 responses to SUBSCRIBE requests and NOTIFY responses to 1252 unknown user agent (see Section 7.6) with no profile data or URIs. 1253 Until the profile delivery server has sent a NOTIFY request with 1254 profile data or URI(s), it has not agreed to provide profiles. 1256 To illustrate why the user agent should not cache the device 1257 profile SUBSCRIBE URI until profile data or URI(s) are provided in 1258 the NOTIFY, consider the following example: a user agent running 1259 on a laptop plugged into a visited LAN in which a foreign profile 1260 delivery server is discovered. The profile delivery server never 1261 provides profile URIs in the NOTIFY request as it is not 1262 provisioned to accept the user agent. The user then takes the 1263 laptop to their enterprise LAN. If the user agent cached the 1264 SUBSCRIBE URI from the visited LAN (which did not provide 1265 profiles), when subsequently placed in the enterprise LAN which is 1266 provisioned to provide profiles to the user agent, the user agent 1267 would not attempt to discover the profile delivery server. 1269 8.1.3 Discovery of User and Application URI 1271 The user's AOR may be preprovisioned or provided via SIM or flash 1272 key, etc. The device profile may define a default user and AOR. If 1273 provided in the device profile and a preprovisioned user AOR is not 1274 provided, the default user's AOR is used to subscribe to the "user" 1275 and "application" profiles. If not provided through the above two 1276 approaches, the AOR to be used for the "user" and "application" 1277 subscription URI, is "discovered" manually by prompting the user. 1278 The URI obtained in the discovery steps described above for the 1279 "user" and "application" profile subscriptions is stored persistantly 1280 in the device until explicitly reset or updated by the user or 1281 profile. 1283 8.2 Enrollment with Profile Server 1285 Enrollment is accomplished by subscribing to the event package 1286 described in Section 7. The enrollment process is useful to the 1287 profile delivery server as it makes the server aware of user agents 1288 to which it may deliver profiles (those user agents the profile 1289 delivery server is provisioned to provide profiles to; those present 1290 to which the server may provide profiles in the future; and those 1291 that the server can automatically provide default profiles). It is 1292 an implementation choice and business policy as to whether the 1293 profile delivery server provides profiles to user agents that it is 1294 not explicitly provisioned to do so. However the profile delivery 1295 server SHOULD accept (with 2xx response) SUBSCRIBE requests from any 1296 user agent as explained in Section 7.5. 1298 8.3 Notification of Profile Changes 1300 The NOTIFY request in the ua-profile event package serves two 1301 purposes. First it provides the user agent with a means to obtain 1302 the profile data directly or via URI(s) for desired profiles without 1303 requiring the end user to manually enter them. It also provides the 1304 means for the profile delivery server to notify the user agent that 1305 the content of the profiles has changed and should be made effective. 1306 Optionally the differential changes may be obtained by notification 1307 by including the content-type: "application/xcap-diff+xml" defined in 1308 [I-D.ietf-simple-xcap-package] in the Accept header of the SUBSCRIBE 1309 request. 1311 8.4 Retrieval of Profile Data 1313 The user agent retrieves its needed profile(s) directly or via the 1314 URI(s) provided in the NOTIFY request as specified in Section 7.5. 1315 The profile delivery server SHOULD secure the content of the profiles 1316 using one of the techniques described in Section 10. The user agent 1317 SHOULD make the new profiles effective in the timeframe described in 1318 Section 7.2. 1320 The contents of the profiles SHOULD be cached (i.e. stored 1321 persistently) by the user agent. The cache should be used if the 1322 user agent is unable to successfully SUBSCRIBE or receive the NOTIFY 1323 providing the most recent profile. The cached profile should be 1324 replaced each time a profile is received in a NOTIFY or retrieved via 1325 content indirection. This it to avoid the situation where the 1326 content delivery server being not available, leaves the user agent 1327 non-functional. The user agent should verify that it has the latest 1328 profile content using the "hash" parameter defined in [I-D.ietf-sip- 1329 content-indirect-mech]. 1331 8.5 Upload of Profile Changes 1333 The user agent or other service MAY push changes up to the profile 1334 delivery server using the technique appropriate to the profile's URL 1335 scheme (e.g. HTTP PUT method, FTP put command). The technique for 1336 pushing incremental or atomic changes MUST be described by the 1337 specific profile data framework. A means for pushing changes up into 1338 the profile delivery server for XCAP is defined in [I-D.ietf-simple- 1339 xcap]. 1341 8.6 Usage of XCAP with the Profile Package 1343 This framework allows for the usage of several different protocols 1344 for the retrieval of profiles. One protocol which is suitable is 1345 XCAP [I-D.ietf-simple-xcap], which allows for HTTP URIs to represent 1346 XML documents, elements and attributes. XCAP defines a specific 1347 hierarchy for how documents are organized. As a result, it is 1348 necessary to discuss how that organization relates to the rough data 1349 model presented here. 1351 When a user or device enrolls with a SUBSCRIBE request, the request 1352 URI will contain identifying information for that user or device. 1353 This identity is mapped to an XCAP User ID (XUID) based on an 1354 implementation specific mapping. The "profile-type" along with the 1355 "auid" Event header parameters specify the specific XCAP application 1356 usage. 1358 In particular, when the Event header parameter "profile-type" is 1359 "application", the "auid" MAY be included to contain the XCAP 1360 Application Unique ID (AUID) [I-D.ietf-simple-xcap]. When the 1361 "profile-type" is "application", but the "auid" parameter is absent, 1362 this specifies that the user wishes to SUBSCRIBE to all documents for 1363 all application usages associated with the user in the request-uri. 1364 This provides a convenient way for a single subscription to be used 1365 to obtain all application data. The XCAP root is determined by a 1366 local mapping. 1368 When the "profile-type" is "device", or "user" or "local-network", 1369 this maps to an AUID and document selector for representing device, 1370 user and local-network data, respectively. The mapping is a matter 1371 of local policy. This allows different providers to use different 1372 XCAP application usages and document schemas for representing these 1373 profiles, without having to configure the device with the specific 1374 AUID which is being used. 1376 Furthermore, when the "document" attribute is present, it identifies 1377 a specific document that is being requested. The "auid" SHOULD NOT 1378 be present if the "document" is also present. The "document" 1379 attribute specifies a relative path reference. The path is 1380 constucted from a set of path segments (e.g. directories) using the 1381 "/" separator. For XCAP the relative document path is constructed 1382 using the following steps:" 1384 1. Its first path segment is either "global", specifying global 1385 data, or "user", specifying user data for the user in the request 1386 URI. 1387 2. If the prior path segment is "user", the next path segment 1388 identifies the the user's home directory. That is the next path 1389 segment is the user's directory name. The user's directory name 1390 is appended onto the "document" path with the "/" separator. If 1391 the prior path segment is "global" nothing is appended to the 1392 document path for this step. 1393 3. When the "profile-type" is "application", the next path segment 1394 to append (i.e. after "global" or the user's home directory 1395 segment) MAY indicate the XCAP Application Unique ID (AUID) if 1396 the user agent wishes to subscribe to a specific application 1397 profile. 1398 4. If the AUID was added to the document path in the prior step, 1399 additional path segments may be added according to the specific 1400 schema of the profile and the query mechanism provided in 1401 [I-D.ietf-simple-xcap]. 1403 For example, consider a phone with an instance ID of 1404 urn:uuid:00000000-0000-0000-0000-0003968cf920. To obtain its device 1405 profile, it would generate a SUBSCRIBE that contains the following 1406 Request-Line and Event header: (Note that line folding of the 1407 Request-URI is illegal in SIP. The Request URI is shown broken 1408 across the first 3-lines here only due to formatting limitations of 1409 IETF documents. The Event header is shown continued across a second 1410 line for the same reason.) 1412 SUBSCRIBE 1413 sip:urn%3auuid%3a00000000-0000-0000-0000-0003968cf920@example.com 1414 SIP/2.0 1415 Event: ua-profile;profile-type=device;Vendor="vendor2"; 1416 Model="1";Version="2.2.2" 1418 If the profile data is stored in an XCAP server, the server would map 1419 the "device" profile to an application usage and document selector 1420 based on local policy. The user ID that might be used in the case of 1421 a device profile could be the device ID which is identified in the 1422 user part of the SUBSCRIBE URI. The XCAP server may use a root 1423 directory of: http://xcap.example.com/root. Local policy may provide 1424 a mapping for the AUID "vendor2-device-data" based upon the "vendor" 1425 parameter and a document called "index" within the user directory, 1426 the corresponding HTTP URI for the document might be: (Note that this 1427 URL is only one line; it is split across three lines due to 1428 formatting limitations of IETF documents.) 1430 http://xcap.example.com/root/users/ 1431 urn%3auuid%3a00000000-0000-0000-0000-0003968cf920/ 1432 vendor2-device-data/index 1434 and indeed, if a content indirection is returned in a NOTIFY, the URL 1435 would equal this. 1437 That user profile might specify the user identity (as a SIP AOR) and 1438 their application-usages. From that, the device can enroll to learn 1439 about its application data. To learn about all of the data: 1441 SUBSCRIBE sip:alice@example.com SIP/2.0 1442 Event: ua-profile;profile-type=application;Vendor="vendor2"; 1443 Model="1";Version="2.2.2" 1445 The server would map the request URI to an XUI (user-aor, for 1446 example) and the xcap root based on local policy. If there are two 1447 AUIDs, "resource-lists" [I-D.ietf-simple-xcap-list-usage] and "rls- 1448 services" [I-D.ietf-simple-xcap-list-usage], this would result in a 1449 subscription to all documents within: 1451 http://xcap.example.com/root/users/user-aor/rls-services 1452 http://xcap.example.com/root/users/user-aor/resource-lists 1454 The user would not be subscribed to the global data for these two 1455 application usages, since that data is not important for users. 1457 However, the user/device could be made aware that it needs to 1458 subscribe to a specific document. In that case, its subscribe would 1459 look like: 1461 SUBSCRIBE sip:user-aor@example.com SIP/2.0 1462 Event: ua-profile;profile-type=application;auid="resource-lists"; 1463 Vendor="vendor2";Model="1";Version="2.2.2" 1465 this would result in a subscription to the single global document for 1466 resource-lists. 1468 In some cases, these subscriptions are to a multiplicity of 1469 documents. In that case, the notification format will need to be one 1470 which can indicate what document has changed. This includes content 1471 indirection, but also the xcap diff format [I-D.ietf-simple-xcap- 1472 package]. 1474 9. IANA Considerations 1476 There are several IANA considerations associated with this 1477 specification. 1479 9.1 SIP Event Package 1481 This specification registers a new event package as defined in 1482 [RFC3265]. The following information required for this registration: 1484 Package Name: ua-profile 1485 Package or Template-Package: This is a package 1486 Published Document: RFC XXXX (Note to RFC Editor: Please fill in 1487 XXXX with the RFC number of this specification). 1488 Person to Contact: Daniel Petrie dan.ietf AT SIPez DOT com 1489 New event header parameters: profile-type, vendor, model, version, 1490 effective-by, document, auid, network-user 1492 10. Security Considerations 1494 Profiles may contain sensitive data such as user credentials and 1495 personal information. The protection of this data depends upon how 1496 the data is delivered. Some profiles may be safe to deliver without 1497 the need to protect the content. For example in some environments 1498 the local network profile may contain the list of codecs that are 1499 acceptable for use in the network and information on NAT traversal 1500 such as a STUN server to use. As the information in this example 1501 local network profile does not contain passwords or sensitive 1502 information it may be acceptable to provide it without authentication 1503 or confidentiality (encryption). We refer to these as non- 1504 confidential profiles. Non-confidential profiles require message 1505 integrity and profile server authentication, as described in 1506 Section 10.3. However any profiles that contain personal 1507 information, passwords or credentials (confidential profiles) require 1508 mutual authentication, confidentiality, and message integrity, and 1509 must follow the guidance provided in the next two subsections. 1510 Profile specifications that define schemas MUST identify if they 1511 contain confidential data to indicate which of the security 1512 approaches describer here should be used. 1514 The profile data is delivered in either the NOTIFY request or via the 1515 URI scheme indicated in the content indirection in the NOTIFY 1516 request. The security approach is different for these two delivery 1517 mechanisms. 1519 Subscribers implementing this specification MUST implement either 1520 HTTP or HTTPS. Subscribers also MUST implement the hash verification 1521 scheme described in SIP content indirection [I-D.ietf-sip-content- 1522 indirect-mech]. SIP profile delivery servers MUST implement both 1523 HTTP and HTTPS, and SHOULD implement a SIP Authentication Service as 1524 described in the SIP Identity mechanism [I-D.ietf-sip-identity]. All 1525 SIP entities are already required to implement SIP Digest 1526 authentication [RFC3261]. 1528 10.1 Confidential Profile Content in NOTIFY Request 1530 When the profile data is delivered directly in the NOTIFY request, 1531 the SUBSCRIBE request MUST be authenticated using the SIP Digest 1532 authentication mechanism. As the profile content is delivered in the 1533 resulting NOTIFY request to the subscription, authenticating the 1534 SUBSCRIBE is the only way to prevent unauthorized access to the 1535 profile data. To provide message integrity and confidentiality over 1536 the profile data, a direct TLS connection MUST be established for the 1537 SUBSCRIBE request. The device SHOULD authenticate the server via the 1538 TLS connection, which also provides a means of verifying that a 1539 direct TLS connection was used (e.g. The device may prompt the user 1540 to verify the Common Name in the server's certificate.). The server 1541 may challenge the device for its certificate, when establishing the 1542 TLS connection, to obtain the public to S/MIME encode the NOTIFY 1543 request body containing the profile data. Because the device 1544 verified that it has a direct TLS connection by verifying the 1545 server's certificate and the server verified the identity of the 1546 device using Digest Authentication, the server can assume the 1547 certficate provided by the device is authenticated. The use of 1548 S/MIME in the NOTIFY request does not relieve the need to 1549 authenticate the SUBSCRIBE request using SIP Digest authentication. 1550 In this scenario S/MIME only provides message integrity and 1551 confidentiality of the content of the profile. If S/MIME is not used 1552 for the profile data in the NOTIFY request, the notifier MUST use the 1553 same direct TLS connection established by device for the SUBSCRIBE 1554 request. In this scenario the use of user specific ID and secret in 1555 the Digest Authentication can be used to establish an association 1556 between user ID and the device ID provide in the device profile 1557 SUBSCRIBE request. 1559 10.2 Confidential Profile Content via Content Indirection 1561 When the profile data is delivered via content indirection, 1562 authentication, integrity, confidentiality are all provided in the 1563 profile indirection retrieval scheme. When content indirection is 1564 used, the SUBSCRIBE request does not need to be authenticated. There 1565 is a TLS certificate approach and a Digest Authentication approach 1566 which may be used to provide the required security. The profile 1567 delivery server MUST support both of these methods. The device MUST 1568 support the Digest Authentication method to provide minimal 1569 interoperablity. 1571 For the TLS certificate approach, the device requests the profile 1572 using HTTPS. To provide authentication, the server challenges the 1573 device for its certificate. The server obtains the user part of the 1574 SIP URI in the Subject Alternative Name field of the device's 1575 certificate. The user part of the SIP URI in the device's 1576 certificate is used as the device ID to authenticate if the device is 1577 authorized to retieive the specified profile. The device 1578 certificates chain of authorities MUST also be verified. This 1579 approach for providing security requires that the device ID and 1580 associated user are provisioned to the content indirection retreival. 1582 For the Digest Authentication approach, HTTPS SHOULD be used to 1583 provide confidentiality of the profile data. HTTP Digest 1584 Authentication [RFC2617] MUST be used to authenticate and authorize 1585 the device to retrieve the profile. The shared secret used in the 1586 Digest Authentication is provided through out of band means to the 1587 device or user of the device. The same credentials used for SIP 1588 Digest authentication (e.g. authenication of SIP SUBSCRIBE and 1589 REGISTER requests) are used in the HTTPS request. Other URI schemes 1590 may be used, but are not defined in this document. A non-replayable 1591 authentication mechanism such as Digest authentication MUST be used 1592 for the content indirection URI scheme which provides the profile 1593 data (e.g. LDAP, HTTP and HTTPS all support Digest authentication). 1594 URI schemes which provide no authentication or only clear-text 1595 authentication SHOULD NOT be used for profile delivery as they are 1596 vulnerable to replay attacks (e.g. TFTP does not provide 1597 authentication). 1598 Without a suitable authentication mechanism, the content 1599 indirection profile delivery URI scheme is susceptible to replay 1600 attacks. Even if the profile is symmetrically encrypted, if it 1601 can be retrieved through a replay attack, the encrypted profile 1602 can be used for offline attacks to crack the encryption key. 1604 The profile delivery scheme MUST use channel security such as TLS 1605 (e.g. HTTPS) to protect the content from being snooped in transport 1606 to the user agent. Mutual authentication using the client and server 1607 certificates MAY be used to verify the authenticity of the user or 1608 device identity and the profile delivery server identity. The user 1609 agent SHOULD provide a mechanism for the user to approve the 1610 SUBSCRIBE server identity or provision the acceptable server identity 1611 through out of band means. 1613 10.3 Integrity protection for non-confidential profiles 1615 Even for non-confidential profiles, the subscriber MUST verify the 1616 authenticity of the profile delivery server, and MUST verify that the 1617 integrity of the profile data and content indirection URI, if one is 1618 provided. To meet these requirements in the SIP messaging the NOTIFY 1619 request MUST use a SIP Identity header [I-D.ietf-sip-identity], or 1620 S/MIME. If content is provided via redirection, the content 1621 indirection "hash" parameter MUST be included unless the profile data 1622 is delivered via a protocol which natively provides authentication 1623 and message integrity, such as HTTP or LDAP protected by TLS. The 1624 content retrieved via the content indirection URI MUST be integrity 1625 checked using the "hash" parameter. 1627 For example, Alice subscribes to the local domain profile for 1628 paris.example.com. She receives the following NOTIFY request which 1629 uses content indirection, including a "hash" parameter. Alice uses 1630 the Identity header from the NOTIFY to verify that the request came 1631 from paris.example.com and that the body was not modified. Then she 1632 fetches the content at the provided URI and verifies that the hash 1633 she calculates from the profile matches the hash provided in the SIP 1634 signaling. 1636 11. Acknowledgements 1638 Many thanks to those who contributed and commented on the many 1639 iterations of this document. Detailed input was provided by Jonathan 1640 Rosenberg from Cisco, Henning Schulzrinne from Columbia University, 1641 Cullen Jennings from Cisco, Rohan Mahy from Airespace, Rich Schaaf 1642 from Pingtel, Volker Hilt from Bell Labs, Adam Roach of Estacado 1643 Systems, Hisham Khartabil from Telio, Henry Sinnreich from MCI, 1644 Martin Dolly from AT&T Labs, John Elwell from Siemens, Elliot Eichen 1645 and Robert Liao from Verizon, Dale Worley from Pingtel. 1647 12. Change History 1649 [[RFC Editor: Please remove this entire section upon publication as 1650 an RFC.]] 1652 12.1 Changes from draft-ietf-sipping-config-framework-06.txt 1654 Restructured the introduction and overview section to be more 1655 consistent with other Internet-Drafts. 1656 Added additional clarifcation for the Digest Authentication and 1657 Certificate based authentication cases in the security section. 1658 Added two use case scenarios with cross referencing to better 1659 illustrate how the framework works. Added better cross 1660 referencing in the overview section to help readers find where 1661 concepts and functionality is defined in the document. 1662 Clarified the section on the use of XCAP. Changed the Event 1663 parameter "App-Id" to "auid". Made "auid" mutually exclusive to 1664 "document". "auid" is now only used with XCAP. 1665 Local network subscription URI changed to @ 1666 (was anonymous@). Having a 1667 different request URI for each device allows the network 1668 management to track user agents and potentially manage bandwidth, 1669 port allocation, etc. 1670 Changed event package name from sip-profile to ua-profile per 1671 discussion on the list and last IETF meeting. 1672 Changed "local" profile type token to "local-network" per 1673 discussion on the list and last IETF meeting. 1674 Simplified "Vendor", "Model", "Version" event header parameters to 1675 allow only quoted string values (previously allowed token as 1676 well). 1677 Clarified use of the term cache. 1678 Added references for ABNF constructs. 1679 Numerous editorial changes. Thanks Dale! 1681 12.2 Changes from draft-ietf-sipping-config-framework-05.txt 1683 Made HTTP and HTTPS profile transport schemes mandatory in the 1684 profile delivery server. The subscribing device must implement 1685 HTTP or HTTPS as the profile transport scheme. 1686 Rewrote the security considerations section. 1687 Divided references into Normative and Informative. 1688 Minor edits throughout. 1690 12.3 Changes from draft-ietf-sipping-config-framework-04.txt 1692 Clarified usage of instance-id 1693 Specify which event header parameters are mandatory or optional 1694 and in which messages. 1695 Included complete list of event header parameters in parameter 1696 overview and IANA sections. 1697 Removed TFTP reference as protocol for profile transport. 1698 Added examples for discovery. 1699 Added ABNF for all event header parameters. 1700 Changed profile-name parameter back to profile-type. This was 1701 changed to profile-name in 02 when the parameter could contain 1702 either a token or a path. Now that the path is contained in the 1703 separate parameter: "document", profile-type make more sense as 1704 the parameter name. 1705 Fixed some statements that should have and should not have been 1706 normative. 1708 Added the ability for the user agent to request that the default 1709 user associated with the device be set/changed using the "network- 1710 user" parameter. 1711 A bunch of editorial nits and fixes. 1713 12.4 Changes from draft-ietf-sipping-config-framework-03.txt 1715 Incorporated changes to better support the requirements for the use 1716 of this event package with XCAP and SIMPLE so that we can have one 1717 package (i.e. simple-xcap-package now defines a content type not a 1718 package). Added an additional profile type: "application". Added 1719 document and app-id Event header parameters in support of the 1720 application profile. Define a loose high level data model or 1721 relationship between the four profile types. Tried to edit and fix 1722 the confusing and ambiguous sections related to URI formation and 1723 discovery for the different profile types. Better describe the 1724 importance of uniqueness for the instance id which is used in the 1725 user part of the device URI. 1727 12.5 Changes from draft-ietf-sipping-config-framework-02.txt 1729 Added the concept of the local network as a source of profile data. 1730 There are now three separate logical sources for profile data: user, 1731 device and local network. Each of these requires a separate 1732 subscription to obtain. 1734 12.6 Changes from draft-ietf-sipping-config-framework-01.txt 1736 Changed the name of the profile-type event parameter to profile-name. 1737 Also allow the profile-name parameter to be either a token or an 1738 explicit URI. 1740 Allow content indirection to be optional. Clarified the use of the 1741 Accept header to indicate how the profile is to be delivered. 1743 Added some content to the Iana section. 1745 12.7 Changes from draft-ietf-sipping-config-framework-00.txt 1747 This version of the document was entirely restructured and re-written 1748 from the previous version as it had been micro edited too much. 1750 All of the aspects of defining the event package are now organized in 1751 one section and is believed to be complete and up to date with 1752 [RFC3265]. 1754 The URI used to subscribe to the event package is now either the user 1755 or device address or record. 1757 The user agent information (vendor, model, MAC and serial number) are 1758 now provided as event header parameters. 1760 Added a mechanism to force profile changes to be make effective by 1761 the user agent in a specified maximum period of time. 1763 Changed the name of the event package from sip-config to ua-profile 1765 Three high level security approaches are now specified. 1767 12.8 Changes from draft-petrie-sipping-config-framework-00.txt 1769 Changed name to reflect SIPPING work group item 1771 Synchronized with changes to SIP DHCP [RFC3361], SIP [RFC3261] and 1772 [RFC3263], SIP Events [RFC3265] and content indirection [I-D.ietf- 1773 sip-content-indirect-mech] 1775 Moved the device identity parameters from the From field parameters 1776 to User-Agent header parameters. 1778 Many thanks to Rich Schaaf of Pingtel, Cullen Jennings of Cisco and 1779 Adam Roach of Estacado Systems for the great comments and input. 1781 12.9 Changes from draft-petrie-sip-config-framework-01.txt 1783 Changed the name as this belongs in the SIPPING work group. 1785 Minor edits 1787 12.10 Changes from draft-petrie-sip-config-framework-00.txt 1789 Split the enrollment into a single SUBSCRIBE dialog for each profile. 1790 The 00 draft sent a single SUBSCRIBE listing all of the desired. 1791 These have been split so that each enrollment can be routed 1792 differently. As there is a concept of device specific and user 1793 specific profiles, these may also be managed on separate servers. 1794 For instance in a roaming situation the device might get its profile 1795 data from a local server which knows the LAN specific profile data. 1796 At the same time the user specific profiles might come from the 1797 user's home environment profile delivery server. 1799 Removed the Config-Expires header as it is largely superfluous with 1800 the SUBSCRIBE Expires header. 1802 Eliminated some of the complexity in the discovery mechanism. 1804 Suggest caching information discovered about a profile delivery 1805 server to avoid an avalanche problem when a whole building full of 1806 devices powers up. 1808 Added the User-Profile From header field parameter so that the device 1809 can request a user specific profile for a user that is different from 1810 the device's default user. 1812 13. References 1814 13.1 Normative References 1816 [I-D.ietf-sip-content-indirect-mech] 1817 Burger, E., "A Mechanism for Content Indirection in 1818 Session Initiation Protocol (SIP) Messages", 1819 draft-ietf-sip-content-indirect-mech-05 (work in 1820 progress), October 2004. 1822 [I-D.ietf-sip-identity] 1823 Peterson, J. and C. Jennings, "Enhancements for 1824 Authenticated Identity Management in the Session 1825 Initiation Protocol (SIP)", draft-ietf-sip-identity-05 1826 (work in progress), May 2005. 1828 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1829 Requirement Levels", BCP 14, RFC 2119, March 1997. 1831 [RFC2132] Alexander, S. and R. Droms, "DHCP Options and BOOTP Vendor 1832 Extensions", RFC 2132, March 1997. 1834 [RFC2246] Dierks, T. and C. Allen, "The TLS Protocol Version 1.0", 1835 RFC 2246, January 1999. 1837 [RFC2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H., 1838 Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext 1839 Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999. 1841 [RFC2617] Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S., 1842 Leach, P., Luotonen, A., and L. Stewart, "HTTP 1843 Authentication: Basic and Digest Access Authentication", 1844 RFC 2617, June 1999. 1846 [RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, May 2000. 1848 [RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, 1849 A., Peterson, J., Sparks, R., Handley, M., and E. 1850 Schooler, "SIP: Session Initiation Protocol", RFC 3261, 1851 June 2002. 1853 [RFC3263] Rosenberg, J. and H. Schulzrinne, "Session Initiation 1854 Protocol (SIP): Locating SIP Servers", RFC 3263, 1855 June 2002. 1857 [RFC3265] Roach, A., "Session Initiation Protocol (SIP)-Specific 1858 Event Notification", RFC 3265, June 2002. 1860 [RFC3361] Schulzrinne, H., "Dynamic Host Configuration Protocol 1861 (DHCP-for-IPv4) Option for Session Initiation Protocol 1862 (SIP) Servers", RFC 3361, August 2002. 1864 13.2 Informative References 1866 [I-D.ietf-simple-xcap] 1867 Rosenberg, J., "The Extensible Markup Language (XML) 1868 Configuration Access Protocol (XCAP)", 1869 draft-ietf-simple-xcap-07 (work in progress), June 2005. 1871 [I-D.ietf-simple-xcap-list-usage] 1872 Rosenberg, J., "Extensible Markup Language (XML) Formats 1873 for Representing Resource Lists", 1874 draft-ietf-simple-xcap-list-usage-05 (work in progress), 1875 February 2005. 1877 [I-D.ietf-simple-xcap-package] 1878 Rosenberg, J., "An Extensible Markup Language (XML) 1879 Document Format for Indicating Changes in XML 1880 Configuration Access Protocol (XCAP) Resources", 1881 draft-ietf-simple-xcap-package-03 (work in progress), 1882 January 2005. 1884 [I-D.ietf-sip-gruu] 1885 Rosenberg, J., "Obtaining and Using Globally Routable User 1886 Agent (UA) URIs (GRUU) in the Session Initiation Protocol 1887 (SIP)", draft-ietf-sip-gruu-04 (work in progress), 1888 July 2005. 1890 [I-D.ietf-sipping-ua-prof-framewk-reqs] 1891 Petrie, D. and C. Jennings, "Requirements for SIP User 1892 Agent Profile Delivery Framework", 1893 draft-ietf-sipping-ua-prof-framewk-reqs-00 (work in 1894 progress), March 2003. 1896 [I-D.petrie-sipping-profile-datasets] 1897 Petrie, D., "A Schema for Session Initiation Protocol User 1898 Agent Profile Data Sets", 1899 draft-petrie-sipping-profile-datasets-00 (work in 1900 progress), July 2004. 1902 [I-D.sinnreich-sipdev-req] 1903 Sinnreich, H., "SIP Telephony Device Requirements and 1904 Configuration", draft-sinnreich-sipdev-req-07 (work in 1905 progress), June 2005. 1907 [RFC0822] Crocker, D., "Standard for the format of ARPA Internet 1908 text messages", STD 11, RFC 822, August 1982. 1910 [RFC0959] Postel, J. and J. Reynolds, "File Transfer Protocol", 1911 STD 9, RFC 959, October 1985. 1913 [RFC2131] Droms, R., "Dynamic Host Configuration Protocol", 1914 RFC 2131, March 1997. 1916 [RFC2141] Moats, R., "URN Syntax", RFC 2141, May 1997. 1918 [RFC2396] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform 1919 Resource Identifiers (URI): Generic Syntax", RFC 2396, 1920 August 1998. 1922 [RFC3377] Hodges, J. and R. Morgan, "Lightweight Directory Access 1923 Protocol (v3): Technical Specification", RFC 3377, 1924 September 2002. 1926 [W3C.REC-xml-names11-20040204] 1927 Tobin, R., Hollander, D., Layman, A., and T. Bray, 1928 "Namespaces in XML 1.1", W3C REC REC-xml-names11-20040204, 1929 February 2004. 1931 Author's Address 1933 Daniel Petrie 1934 SIPez LLC. 1935 34 Robbins Rd 1936 Arlington, MA 02476 1937 US 1939 Phone: "+1 617 273 4000 1940 Email: dan.ietf AT SIPez DOT com 1941 URI: http://www.SIPez.com/ 1943 Intellectual Property Statement 1945 The IETF takes no position regarding the validity or scope of any 1946 Intellectual Property Rights or other rights that might be claimed to 1947 pertain to the implementation or use of the technology described in 1948 this document or the extent to which any license under such rights 1949 might or might not be available; nor does it represent that it has 1950 made any independent effort to identify any such rights. 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