idnits 2.17.1 draft-ietf-sipping-config-framework-09.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- ** It looks like you're using RFC 3978 boilerplate. You should update this to the boilerplate described in the IETF Trust License Policy document (see https://trustee.ietf.org/license-info), which is required now. -- Found old boilerplate from RFC 3978, Section 5.1 on line 14. -- Found old boilerplate from RFC 3978, Section 5.5 on line 2028. -- Found old boilerplate from RFC 3979, Section 5, paragraph 1 on line 2005. -- Found old boilerplate from RFC 3979, Section 5, paragraph 2 on line 2012. -- Found old boilerplate from RFC 3979, Section 5, paragraph 3 on line 2018. ** 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 1932 has weird spacing: '... Change 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 [RFC2131](option 15 [RFC2132]). 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. == 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 request URI for profile-type=localnet now SHOULD not have a user part to make routing easier. The From field SHOULD now contain the device id so that device tracking can still be done. Described the concept of profile-type as a filter and added normative text requiring 404 for profile types not provided. Moved "application" profile type to draft-ietf-sipping-xcap-config-01. The "application" value for the profile-type parameter will also be used as a requirement that XCAP be supported. Fixed text on certificate validation. Added new HTTP header: Event to IANA section and clean up the IANA section. Added diagram for service provider use case schenario. Added clarification for HTTP Event header. Added clarification of subscriber handling of NOTIFY with no body. -- The document seems to lack a disclaimer for pre-RFC5378 work, but may have content which was first submitted before 10 November 2008. If you have contacted all the original authors and they are all willing to grant the BCP78 rights to the IETF Trust, then this is fine, and you can ignore this comment. If not, you may need to add the pre-RFC5378 disclaimer. (See the Legal Provisions document at https://trustee.ietf.org/license-info for more information.) -- The document date (October 3, 2006) is 6414 days in the past. Is this intentional? Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Missing Reference: 'RFCXXXX' is mentioned on line 1441, but not defined == Unused Reference: 'I-D.petrie-sipping-profile-datasets' is defined on line 1948, but no explicit reference was found in the text ** Obsolete normative reference: RFC 2246 (Obsoleted by RFC 4346) ** Obsolete normative reference: RFC 2616 (Obsoleted by RFC 7230, RFC 7231, RFC 7232, RFC 7233, RFC 7234, RFC 7235) ** Obsolete normative reference: RFC 2617 (Obsoleted by RFC 7235, RFC 7615, RFC 7616, RFC 7617) ** Obsolete normative reference: RFC 2818 (Obsoleted by RFC 9110) ** Obsolete normative reference: RFC 3265 (Obsoleted by RFC 6665) == Outdated reference: A later version (-12) exists of draft-ietf-simple-xcap-11 == Outdated reference: A later version (-14) exists of draft-ietf-simple-xcap-diff-03 == Outdated reference: A later version (-20) exists of draft-ietf-sip-outbound-04 == Outdated reference: A later version (-05) exists of draft-petrie-sipping-profile-datasets-03 -- Obsolete informational reference (is this intentional?): RFC 822 (Obsoleted by RFC 2822) -- Obsolete informational reference (is this intentional?): RFC 2141 (Obsoleted by RFC 8141) -- Obsolete informational reference (is this intentional?): RFC 2396 (Obsoleted by RFC 3986) -- Obsolete informational reference (is this intentional?): RFC 3377 (Obsoleted by RFC 4510) Summary: 8 errors (**), 0 flaws (~~), 13 warnings (==), 11 comments (--). 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: April 6, 2007 October 3, 2006 6 A Framework for Session Initiation Protocol User Agent Profile Delivery 7 draft-ietf-sipping-config-framework-09.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 April 6, 2007. 34 Copyright Notice 36 Copyright (C) The Internet Society (2006). 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 that a user 43 agent needs to be functional, without user or administrative 44 intervention. The framework for discovery, delivery, notification 45 and updates of user agent profile data is defined here. As part of 46 this framework a new SIP event package is defined here for the 47 notification of profile changes. This framework is also intended to 48 ease ongoing administration and upgrading of large scale deployments 49 of SIP user agents. The contents and format of the profile data to 50 be defined is 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 . . . . . . . . . . . . 5 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 . . . . . . . . . . . . . . . . . . . . . . . . . . 10 64 7. Profile Change Event Notification Package . . . . . . . . . . 11 65 7.1. Event Package Name . . . . . . . . . . . . . . . . . . . 12 66 7.2. Event Package Parameters . . . . . . . . . . . . . . . . 12 67 7.3. SUBSCRIBE Bodies . . . . . . . . . . . . . . . . . . . . 16 68 7.4. Subscription Duration . . . . . . . . . . . . . . . . . . 16 69 7.5. NOTIFY Bodies . . . . . . . . . . . . . . . . . . . . . . 16 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 URIs . . . . . . . . . . . . . . . . . . . . . . 24 80 7.13.3. Local Network URIs . . . . . . . . . . . . . . . . . 24 81 8. Profile Delivery Framework Details . . . . . . . . . . . . . . 25 82 8.1. Discovery of Subscription URI . . . . . . . . . . . . . . 25 83 8.1.1. Discovery of Local Network URI . . . . . . . . . . . 25 84 8.1.2. Discovery of Device URI . . . . . . . . . . . . . . . 26 85 8.1.3. Discovery of User URI . . . . . . . . . . . . . . . . 29 86 8.2. Enrollment with Profile Server . . . . . . . . . . . . . 29 87 8.3. Notification of Profile Changes . . . . . . . . . . . . . 29 88 8.4. Retrieval of Profile Data . . . . . . . . . . . . . . . . 30 89 8.5. Upload of Profile Changes . . . . . . . . . . . . . . . . 30 90 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 30 91 9.1. SIP Event Package . . . . . . . . . . . . . . . . . . . . 30 92 9.2. New HTTP Event Header . . . . . . . . . . . . . . . . . . 31 93 10. Security Considerations . . . . . . . . . . . . . . . . . . . 31 94 10.1. Confidential Profile Content in NOTIFY Request . . . . . 32 95 10.2. Confidential Profile Content via Content Indirection . . 33 96 10.3. Integrity protection for non-confidential profiles . . . 34 97 10.4. Initial Enrollment Using a Manufacturer's Certificate . . 34 98 11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 36 99 12. Change History . . . . . . . . . . . . . . . . . . . . . . . . 36 100 12.1. Changes from 101 draft-ietf-sipping-config-framework-08.txt . . . . . . . 36 102 12.2. Changes from 103 draft-ietf-sipping-config-framework-07.txt . . . . . . . 36 104 12.3. Changes from 105 draft-ietf-sipping-config-framework-06.txt . . . . . . . 37 106 12.4. Changes from 107 draft-ietf-sipping-config-framework-05.txt . . . . . . . 37 108 12.5. Changes from 109 draft-ietf-sipping-config-framework-04.txt . . . . . . . 38 110 12.6. Changes from 111 draft-ietf-sipping-config-framework-03.txt . . . . . . . 38 112 12.7. Changes from 113 draft-ietf-sipping-config-framework-02.txt . . . . . . . 38 114 12.8. Changes from 115 draft-ietf-sipping-config-framework-01.txt . . . . . . . 39 116 12.9. Changes from 117 draft-ietf-sipping-config-framework-00.txt . . . . . . . 39 118 12.10. Changes from 119 draft-petrie-sipping-config-framework-00.txt . . . . . . 39 120 12.11. Changes from draft-petrie-sip-config-framework-01.txt . . 40 121 12.12. Changes from draft-petrie-sip-config-framework-00.txt . . 40 122 13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 40 123 13.1. Normative References . . . . . . . . . . . . . . . . . . 40 124 13.2. Informative References . . . . . . . . . . . . . . . . . 41 125 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 44 126 Intellectual Property and Copyright Statements . . . . . . . . . . 45 128 1. Introduction 130 Today all SIP (Session Initiation Protocol) [RFC3261] user agent 131 implementers use proprietary means of delivering user, device and 132 local network policy profiles to the user agent. The profile 133 delivery framework defined in this document is intended to enable a 134 first phase migration to a standard means of providing profiles to 135 SIP user agents. It is expected that UA (User Agent) implementers 136 will be able to use this framework as a means of delivering their 137 existing proprietary data profiles (i.e. using their existing 138 proprietary binary or text formats). This in itself is a tremendous 139 advantage in that a SIP environment can use a single profile delivery 140 server for profile data to user agents from multiple implementers. 141 Follow-on standardization activities can: 142 1. define a standard profile content format framework (e.g. XML 143 with namespaces [W3C.REC-xml-names11-20040204] or name-value 144 pairs [RFC0822]). 145 2. specify the content (i.e. name the profile data parameters, xml 146 schema, name spaces) of the data profiles. 148 One of the objectives of the framework described in this document is 149 to provide a start up experience similar to that of users of an 150 analog telephone. When you plug in an analog telephone it just works 151 (assuming the line is live and the switch has been provisioned). 152 There is no end user configuration required to make analog phone 153 work, at least in a basic sense. So the objective here is to be able 154 to take a new SIP user agent out of the box, plug it in or install 155 the software and have it get its profiles without human intervention 156 other than security measures. This is necessary for cost effective 157 deployment of large numbers of user agents. 159 Another objective is to provide a scalable means for ongoing 160 administration of profiles. Administrators and users are likely to 161 want to make changes to profiles. 163 Additional requirements for the framework defined in this document 164 are described in: [I-D.ietf-sipping-ua-prof-framewk-reqs], 165 [I-D.sinnreich-sipdev-req] 167 2. Requirements Terminology 169 Keywords "MUST", "MUST NOT", "REQUIRED", "SHOULD", "SHOULD NOT" and 170 "MAY" that appear in this document are to be interpreted as described 171 in [RFC2119]. 173 3. Profile Delivery Framework Terminology 175 profile - data set specific to a user, device, or the local network. 176 device - software or hardware appliance containing one or more SIP 177 user agents. 178 profile content server - The server that provides the content of the 179 profiles using the protocol specified by the URI scheme. 180 notifier - As defined in [RFC3265] the SIP user agent server which 181 processes SUBSCRIBE requests for events and sends NOTIFY requests 182 with profile data or URIs (Uniform Resource Identifiers) that 183 point to the data. 184 profile delivery server - The logical collection of the notifier and 185 the server which provides the contents of the notification either 186 directly in the NOTIFY requests or indirectly via profile URI(s). 187 hotelling- when a user moves to a new user agent (i.e. that is not 188 already provisioned to know the user's identity, credentials or 189 profile data) and gives the user agent sufficient information to 190 retrieve the user's profile(s). The user agent either permanently 191 or temporarily makes the user's profiles effective on that user 192 agent. 193 nomadic- when the user agent moves to a different local network 194 instance id- text identifier globally unique across all user agent 195 (soft and hard devices) 197 4. Overview 199 The profile life cycle can be described by five functional steps. 200 These steps are not necessarily discrete. However it is useful to 201 describe these steps as logically distinct. These steps are named as 202 follows: 204 Discovery - discover a profile delivery server 205 Enrollment - enroll with the profile delivery server 206 Profile Retrieval - retrieve profile data 207 Profile Change Notification - receive notification of profile changes 208 Profile Change Upload - upload profile data changes back to the 209 profile delivery server 211 Discovery is the process by which a UA finds the address and port at 212 which it enrolls with the profile delivery server. As there is no 213 single discovery mechanism which will work in all network 214 environments, a number of discovery mechanisms are defined with a 215 prescribed order in which the UA tries them until one succeeds. The 216 means of discovery is described in Section 8.1. 218 Enrollment is the process by which a UA makes itself known to the 219 profile delivery server. In enrolling, the UA provides identity 220 information, requested profile type(s) and supported protocols for 221 profile retrieval. It also subscribes to a mechanism for 222 notification of profile changes. As a result of enrollment, the UA 223 receives the data or the URI for each of the profiles that the 224 profile delivery server is able to provide. Each profile type (set) 225 requires a separate enrollment or SUBSCRIBE session. A profile type 226 may represent one or more data sets. Enrollment which is performed 227 by the device by constructing and sending a SUBSCRIBE request to 228 profile delivery server for the event package described in Section 7. 230 Profile Retrieval is the process of retrieving the content for each 231 of the profiles requested by the UA. The profiles are retrieved 232 either directly or indirectly from the NOTIFY request body as 233 described in Section 7.5 and Section 8.4. 235 Profile Change Notification is the process by which the profile 236 delivery server notifies the UA that the content of one or more of 237 the profiles has changed. If the content is provided indirectly, the 238 UA MAY retrieve the profile from the specified URI upon receipt of 239 the change notification. Profile change notification is provided by 240 the NOTIFY request for the event package as described in Section 7.8 241 and Section 8.3. 243 Profile Change Upload is the process by which a UA or other entity 244 (e.g. corporate directory or configuration management server) pushes 245 a change to the profile data back up to the profile delivery server. 246 This process is described in Section 8.5. 248 This framework defines a new SIP event package [RFC3265] to solve 249 enrollment and profile change notification steps. The event package 250 in Section 7 defines everything but the mandatory content type. This 251 makes this event package abstract until the content type is bound. 252 The profile content type definition is outside of scope for this 253 document. It is the author's belief that it would be a huge 254 accomplishment if all SIP user agents used this framework for 255 delivering their existing proprietary profiles. Even though this 256 does not accomplish interoperability of profiles, it is a big first 257 step in easing the administration of SIP user agents. The definition 258 of standard profiles and data sets (see [I-D.petrie-sipping-profile- 259 datasets] ) will enable interoperability as a subsequent step. 261 The question arises as to why SIP should be used for the profile 262 delivery framework. In this document SIP is used for only a small 263 portion of the framework. Other existing protocols are more 264 appropriate for transport of the profile contents (to and from the 265 user agent) and are suggested in this document. The discovery step 266 is simply a specified order and application of existing protocols 267 (see Section 8.1). SIP is only needed for the enrollment (see 268 Section 8.2) and change notification functionality (see Section 8.3) 269 of the profile delivery framework. In many SIP environments (e.g. 270 carrier/subscriber and multi-site enterprise) firewall, NAT (Network 271 Address Translation) and IP addressing issues make it difficult to 272 get messages between the profile delivery server and the user agent 273 requiring the profiles. 275 With SIP the users and devices already are assigned globally routable 276 addresses. In addition the firewall and NAT problems are already 277 presumably solved in the environments in which SIP user agents are to 278 be used. The local network profile (see Section 6, Section 7.13.3 279 and Section 8.1.1) provides the means to get firewall and NAT 280 traversal mechanism information to the device. Therefore SIP is the 281 best solution for allowing the user agent to enroll with the profile 282 delivery server, which may require traversal of multiple firewalls 283 and NATs. For the same reason the notification of profile changes is 284 best solved by SIP. It should be noted that this document is scoped 285 to providing profiles for devices which contain one or more SIP user 286 agents. This framework may be applied to non-SIP devices, however 287 more general requirements for non-SIP devices are beyond the scope of 288 this document. 290 The content delivery server may be either in the public network or 291 accessible through a private network. The user agents requiring 292 profiles may be behind firewalls and NATs and many protocols, such as 293 HTTP, may be used for profile content retrieval without special 294 consideration in the firewalls and NATs (e.g. an HTTP client on the 295 UA can typically pull content from a server outside the NAT/ 296 firewall.). 298 5. Use Cases 300 The following use cases are intended to help give an understanding of 301 how the profile delivery framework can be used. These use cases are 302 not intended to be exhaustive in demonstrating all of the 303 capabilities or ways the framework can be applied. 305 5.1. Service Provider Use Case Scenario Bootstrapping with Digest 306 Authentication 308 The following describes a use case scenario for bootstrapping a new 309 user agent, which has had no prior provisioned information, to the 310 point of being functional with a SIP Service Provider's system. In 311 this example scenario, the user has purchased a new SIP user agent. 312 The user signs up for the service to obtain three pieces of 313 information: a hostname, a user ID and a password. These three 314 pieces of information may be one-time use, that become invalid after 315 the one use. This scenario assumes that no association or mapping 316 between the device and the user's account is created before the 317 following steps: 319 |Service Provider | 320 |Profile Delivery Server| 321 | ___ _____ | 322 | |SIP| |HTTPS| | 323 |_|___|_________|_____|_| 324 A A 325 | | 326 \___ |-5A) HTTP GET of device profile 327 \ |-6) HTTPS response w/device profile 328 \ | ______________ 329 \ | | Residential | 330 4) NOTIFY on-\ \ | Router ____ | 331 existing TLS \ \ | |DHCP| | 332 connetion \ \ |_______|____|_| 333 \ \ A A 334 \ \ 1B) SUBSCRIBE-| | 335 \ \ local network| | 336 \ \ profile| | 337 \ \ | | 338 \ \ | |-1A) DHCP 339 \ \ | |request 340 \ \ | | 341 \ \ C=======D 342 3) SIP/TLS SUBSCRIBE to device profile-\ \ /^\ 343 7) reSUBSCRIBE to device profile as-\ / \ 344 configured in device profile / Device \ 345 ----------- 346 2) User enters service provider hostname 347 5B) User enters HTTP profile userID and password 349 1. The user plugs the device in to provide power and network 350 connectivity the first time (or installs the software in the case 351 of a software user agent). The device subscribes to the local 352 network to get the local network profile. However as the device 353 is plugged into a residential LAN or router, there is no profile 354 delivery server for the local network profile (see Section 8.1.1 355 and Section 7.13.3). 356 2. The device prompts the user for the hostname to subscribe to for 357 the device profile. The hostname was provided by the service 358 provider and is used as the host part of the SUBSCRIBE profile 359 URI described in Section 7.13.1. Note: in a scenario where the 360 system operator (e.g. enterprise) has control of the network, the 361 hostname for the SUBSCRIBE can be discovered (see Section 8.1.2) 362 to avoid the need for the user to enter the hostname. 364 3. The device creates a TLS [RFC2246] connection for the SIP 365 SUBSCRIBE request to the provided hostname. The device verifies 366 the server's certificate. If the SubjectAltName does not match 367 the hostname or the certificate is not valid (as described in 368 Section 23 of [RFC3261]), the device warns the user and prompts 369 whether to continue. 370 4. The profile delivery server receives the SUBSCRIBE request for 371 the device profile and sends a NOTIFY with content indirection 372 containing the HTTPS URI for the device profile (see 373 Section 7.5). 374 5. The device receives the NOTIFY request with the device profile 375 URI. The device prompts the user for the user ID and password 376 provided by the service provider. The device does an HTTPS GET 377 to retrieve the device profile (see Section 8.4 and Section 7.8). 378 The profile delivery server challenges for Digest authentication. 379 The device re-sends the HTTPS GET with Digest credentials using 380 the user ID and password entered by the user. 381 6. The profile delivery server receives the HTTP GET request for the 382 device profile along with the user ID and password for the 383 specific user. At this point, the profile delivery server has 384 authenticated the user and can create an association between a 385 specific device identified in the HTTPS URI and the user or user 386 account (see Section 10.2). The profile delivery server provides 387 the device profile which may contain the on-going SUBSCRIBE 388 request URIs for the device, user and other profiles along with 389 credentials for retrieving the profiles. 390 7. The device receives the device profile from the HTTPS response, 391 re-SUBSCRIBEs using the device profile URI provided in the 392 profile. The device profile also may contain URIs for the 393 default user's user and other profile SUBSCRIBE request URIs for 394 the SIP event package defined in Section 7. The device uses 395 these URIs to retrieve user and other profiles in a similar way 396 to the device profile. After retrieving these profiles the 397 device is fully functional in the service provider's SIP service. 399 5.2. Service Provider Use Case Scenario Bootstrapping with Device 400 Certificate 402 The following describes another use case scenario where the device 403 implementor provides a certificate for the device which authenticates 404 the device ID. In this scenario, the user signs up for the SIP 405 service with the service provider and provides the device ID (see 406 Section 7.13.1 for more information on device ID) to the service 407 provider prior to the following steps, so that the service provider 408 has an association or mapping between the device ID and the user 409 account ahead of time. The service provider gives the user a 410 hostname to be entered on the device. 412 1. Steps 1-3 occur the same as in the prior use case described in 413 Section 5.1. 414 2. The device receives the NOTIFY request with the device profile 415 URI. The device does an HTTPS GET to retrieve the device profile 416 (see Section 8.4 and Section 7.8). 417 3. The profile delivery server requests the device certificate in 418 the TLS connection used for the HTTPS GET. The device has a 419 certificate that contains the MAC address used in the device ID. 420 The device certificate is signed and provided by the implementor 421 for the purpose of authenticating the device ID in the initial 422 bootstrapping process only. The profile delivery server 423 validates the device ID and returns the device profile using 424 HTTPS. 425 4. The device receives the device profile in the HTTPS response. 426 The process continues in a similar way to step 7 in the above use 427 case. The device profile contains a more permanent device 428 certificate and private key or Digest authentication credentials 429 which are used for on-going device ID authentication. 431 6. Data Model 433 A conscious separation of device, user and local network profiles is 434 made in this document. This is useful to provide features such as 435 hotelling (described above) as well as securing or restricting user 436 agent functionality. For example, by maintaining this separation, 437 Alice may walk up to Bob's user agent and direct Bob's user agent to 438 get the Alice's profile data. In doing so the user agent can replace 439 the previous user's profile data while still keeping the device's and 440 the local network's profile data which may be necessary for core 441 functionality and communication described in this document. The 442 local network profiles are relevant to a visiting device which gets 443 plugged in to a foreign network. The concept of the local network 444 providing profile data is useful to provide nomadic capabilities 445 (described above) as well as local policy data that may constrain the 446 user or device behavior relative to the local network. For example, 447 media types and codecs may be constrained to reflect the network's 448 capabilities. 450 The separation of these profiles also enables the separation of the 451 management of the profiles. The user profile may be managed by a 452 profile delivery server operated by the user's ISP. The device 453 profile may be delivered from a profile delivery server operated by 454 the user's employer. Other profile(s) may be delivered from the 455 user's ASP (Application Service Provider). The local network profile 456 may delivered by a WLAN (Wireless LAN) hotspot service provider. 457 Some interesting services and mobility applications are enabled with 458 this separation of profiles. 460 A very high level data model is implied here with the separation of 461 these three profile types. Each profile type instance requires a 462 separate subscription to retrieve the profile. A loose hierarchy 463 exists mostly for the purpose of bootstrapping and discovery or 464 formation of the profile URIs. No other meaning is implied by this 465 hierarchy. However, the profile format and data sets to be defined 466 outside this document may define additional meaning to this 467 hierarchy. In the bootstrapping scenario, a device straight out of 468 the box (software or hardware) does not know anything about its user 469 or local network. The one thing that it does know is its instance 470 id. So the hierarchy of the profiles exists as follows. 472 The local network profile is subscribed to and retrieved based upon a 473 URI formed from the local network domain. The local network profile 474 is subscribed to first as it may contain information on how to 475 communicate to the Internet or primary network from the local network 476 (e.g. HTTP proxy, SIP firewall or NAT traversal information). The 477 device instance id is used to form the user id part of the URI for 478 subscribing to the device and local network profiles. The device 479 profile may contain a default user AOR (Address of Record) for that 480 device. The default user AOR may then be used to retrieve the user 481 profile. Applications to be used on the device may be defined in the 482 device and user profiles. 484 7. Profile Change Event Notification Package 486 This section defines a new SIP event package [RFC3265]. The purpose 487 of this event package is to send to subscribers notification of 488 content changes to the profile(s) of interest and to provide the 489 location of the profile(s) via content indirection [I-D.ietf-sip- 490 content-indirect-mech] or directly in the body of the NOTIFY. 491 Frequently the profiles delivered to the user agent are much larger 492 (e.g. several KB or even several MB) than the MTU of the network. 493 These larger profiles will cause larger than normal SIP messages and 494 consequently higher impact on the SIP servers and infrastructure. To 495 avoid the higher impact and load on the SIP infrastructure, content 496 indirection SHOULD be used if the profile is large enough to cause 497 packet fragmentation over the transport protocol. The presence of 498 the MIME type for content indirection [I-D.ietf-sip-content-indirect- 499 mech] in the Accept header indicates that the user agent supports 500 content indirection and that the profile delivery server SHOULD use 501 content indirection. Similarly the content type for the differential 502 notification of profile changes [I-D.ietf-simple-xcap-diff] may be 503 used in the Accept header to express support for receiving profile 504 change deltas. 506 The MIME types or formats of profiles to be delivered via this 507 framework are to be defined in the documents that define the profile 508 contents. These profile MIME types specified in the Accept header 509 along with the profile types specified in the Event header parameter 510 "profile-type" SHOULD be used to specify which profiles get delivered 511 either directly or indirectly in the NOTIFY requests. As this event 512 package does not specify the mandatory content type, this package is 513 abstract. The profile definition documents will specify the 514 mandatory content type to make a concrete event package. 516 7.1. Event Package Name 518 The name of this package is "ua-profile". This value appears in the 519 Event header field present in SUBSCRIBE and NOTIFY requests for this 520 package as defined in [RFC3265]. 522 7.2. Event Package Parameters 524 This package defines the following new parameters for the event 525 header: "profile-type", "vendor", "model", "version", "effective-by", 526 and "network-user". The "effective-by" parameter is for use in 527 NOTIFY requests only. The "effective-by" parameter is ignored if it 528 appears in a SUBSCRIBE request. The other parameters are for use in 529 the SUBSCRIBE request and are ignored if they appear in NOTIFY 530 requests. 532 The "profile-type" parameter is used to indicate the token name of 533 the profile type the user agent wishes to obtain data or URIs for and 534 to be notified of subsequent changes. Using a token in this 535 parameter allows the URI semantics for retrieving the profiles to be 536 opaque to the subscribing user agent. All it needs to know is the 537 token value for this parameter. This document defines three logical 538 types of profiles and their token names. The contents or format of 539 the profiles is outside the scope of this document. 541 The three types of profiles defined here are "device", "user" and 542 "local-network". Specifying "device" type profile(s) indicates the 543 desire for the profile data (URI when content indirection is used) 544 and change notification of the contents of the profile that is 545 specific to the device or user agent. Specifying "user" type profile 546 indicates the desire for the profile data (URI when content 547 indirection is used) and change notification of the profile content 548 for the user. Specifying "local-network" type profile indicates the 549 desire for profile data (URI when content indirection is used) 550 specific to the local network. The device, user or local network is 551 identified in the URI of the SUBSCRIBE request. A separate SUBSCRIBE 552 dialog is used for each profile type. The profile type associated 553 with the dialog can then be used to infer which profile type changed 554 and is contained in the NOTIFY or content indirection URI. The 555 Accept header of the SUBSCRIBE request MUST include the MIME types 556 for all profile content types for which the subscribing user agent 557 wishes to retrieve profiles or receive change notifications. In the 558 following ABNF, EQUAL and token are defined in [RFC3261]. Additional 559 profile types may be defined in subsequent documents. 561 Profile-type = "profile-type" EQUAL profile-value 562 profile-value = profile-types / token 563 profile-types = "device" / "user" / "local-network" 565 The "device", "user" or "local-network" token in the profile-type 566 parameter may represent a class or set of profile properties. As 567 standards are defined for specific profile contents related to the 568 user, device or local network, it may be desirable to define 569 additional tokens for the profile-type parameter. Also additional 570 content types may be defined along with the profile formats that 571 can be used in the Accept header of the SUBSCRIBE to filter or 572 indicate what data sets of the profile are desired. 574 The rationale for the separation of user, device and local network 575 type profiles is provided in Section 4. It should be noted that any 576 of the types may result in zero or more profiles or URIs being 577 provided in the NOTIFY request. As discussed, a default user may be 578 assigned to a device. The default user's AOR, if defined in the 579 device profile, may in turn be used as the URI to SUBSCRIBE to the 580 "user" profile type. 582 The data provided in the three types of profiles may overlap. As an 583 example, the codecs that a user prefers to use, the codecs that the 584 device supports (and the enterprise or device owner wishes to use), 585 the codecs that the local network can support (and the network 586 operator wishes to allow) all may overlap in how they are specified 587 in the three corresponding profiles. This policy for merging the 588 constraints across the multiple profile types can only unambiguously 589 be defined in the context of the profile syntax and semantics. This 590 is out of scope for this document and will be defined in a subsequent 591 document(s) that define the data profile format. 593 The "vendor", "model" and "version" parameter values are tokens 594 specified by the implementer of the user agent. These parameters 595 MUST be provided in the SUBSCRIBE request for all profile types. The 596 implementer SHOULD use their DNS domain name (e.g. example.com) as 597 the value of the "vendor" parameter so that it is known to be unique. 598 These parameters are useful to the profile delivery server to affect 599 the profiles provided. In some scenarios it is desirable to provide 600 different profiles based upon these parameters. For example, feature 601 property X in a profile may work differently on two versions of the 602 same user agent. This gives the profile delivery server the ability 603 to compensate for or take advantage of the differences. In the 604 following ABNF, EQUAL and quoted-string are defined in [RFC3261]. 606 Vendor = "vendor" EQUAL quoted-string 607 Model = "model" EQUAL quoted-string 608 Version = "version" EQUAL quoted-string 610 The "network-user" parameter MUST be set when subscribing for device 611 profiles if the user's AOR is known. The "network-user" parameter 612 MUST be set when subscribing for "local-network" profiles if it is 613 known, unless the device is provisioned to preserve privacy within 614 the local network. 615 When the profile-type is "device", the SUBSCRIBE URI addresses the 616 device which must contain the device identity (see Section 7.13). 617 When the profile-type is "local-network", the SUBSCRIBE URI 618 addresses the local network profile resource id which must contain 619 the localdomain with no user part (see Section 7.13). The URIs 620 will not contain the user profile identifier. For this reason the 621 "network-user" parameter is needed to indicate the user profile 622 resource identifier associated with the "device" or URI. 623 The SUBSCRIBE server SHOULD authenticate the subscriber to verify the 624 resource identifier in the "network-user" parameter if the profile 625 provided is specific to the user (e.g. granting policies or 626 privileges beyond those of a default user). If the value of the 627 "profile-type" parameter is not "device" or "local-network", the 628 "network-user" parameter has no defined meaning and is ignored. If 629 the "network-user" parameter is provided in the SUBSCRIBE request, it 630 MUST be present in the NOTIFY request as well. In the following 631 ABNF, EQUAL, LDQUOT, RDQUOT and addr-spec are defined in [RFC3261]. 633 Network-User = "network-user" EQUAL LDQUOT addr-spec RDQUOT 635 The entity that is subscribing and getting the "device" and 636 "local-network" profiles is the device. For this reason the From 637 field should indicate the device's identity. These profiles types 638 contain device specific information and it is the device's 639 identity that gets authenticated for the "device" profile. 640 Depending upon the local administration policy and segmentation of 641 services, the device identity and user profile identity 642 association may not be known to the configuration delivery server 643 ahead of time. Since the From field and SUBSCRIBE request URI 644 indicate the "device" profile resource identifier, the "network- 645 user" parameter is needed to indicate the additional resource 646 identifier for the user associated with this device. 647 When the profile-type is "device", the user agent SHOULD set the 648 "network-user" parameter to the "user" profile resource identifier if 649 it is known. This is an indication to the profile delivery server to 650 set or change the association of the default user with the device 651 indicated in the SUBSCRIBE URI. If the profile delivery server 652 implements and allows this policy of setting the default user with a 653 device, the user agent can utilize this mechanism to allow a user to 654 login and make the user agent and user association permanent. 656 If the profile-type is "local-network" and users's AOR is known, the 657 user agent SHOULD assign the "network-user" parameter to be the 658 user's AOR. If the user has special privileges beyond that of a 659 default user in the local network, the "network-user" parameter 660 identifies the user to the local network. 662 The "effective-by" parameter in the Event header of the NOTIFY 663 request specifies the maximum number of seconds before the user agent 664 must attempt to make the new profile effective. The "effective-by" 665 parameter MAY be provided in the NOTIFY request for any of the 666 profile types. A value of 0 (zero) indicates that the subscribing 667 user agent must attempt to make the profiles effective immediately 668 (despite possible service interruptions). This gives the profile 669 delivery server the power to control when the profile is effective. 670 This may be important to resolve an emergency problem or disable a 671 user agent immediately. The "effective-by" parameter is ignored in 672 all messages other than the NOTIFY request. In the following ABNF, 673 EQUAL and DIGIT are defined in [RFC3261]. 675 Effective-By = "effective-by" EQUAL 1*DIGIT 677 The following are example Event headers which may occur in 678 SUBSCRIBE requests. These examples are not intended to be 679 complete SUBSCRIBE requests. 681 Event: ua-profile;profile-type=device; 682 vendor="vendor.example.com";model="Z100";version="1.2.3" 684 Event: ua-profile;profile-type="user"; 685 vendor="premier.example.com";model="trs8000";version="5.5" 687 The following are example Event headers which may occur in 688 NOTIFY requests. These example headers are not intended to 689 be complete SUBSCRIBE requests. 691 Event: ua-profile;effective-by=0 693 Event: ua-profile;effective-by=3600 695 The following table shows the use of Event header parameters in 696 SUBSCRIBE requests for the three profile types: 698 profile-type || device | user | local-network 699 ============================================= 700 vendor || m | m | m 701 model || m | m | m 702 version || m | m | m 703 network-user || s | | s 704 effective-by || | | 706 m - mandatory 707 s - SHOULD be provided 708 o - optional 709 Non-specified means that the parameter has no meaning and 710 should be ignored. 712 The following table shows the use of Event header parameters in 713 NOTIFY requests for the three profile types: 715 profile-type || device | user | local-network 716 ============================================= 717 vendor || | | 718 model || | | 719 version || | | 720 network-user || s | | s 721 effective-by || o | o | o 723 7.3. SUBSCRIBE Bodies 725 This package defines no use of the SUBSCRIBE request body. A body 726 contained in a SUBSCRIBE request for this event package is ignored. 727 Future documents may specify a filter-like mechanism using etags to 728 minimize the delivery or notification of profiles where the user 729 agent already has a current version. 731 7.4. Subscription Duration 733 As the presence (or lack of) a device or user agent is not very time 734 critical to the functionality of the profile delivery server, it is 735 recommended that the default subscription duration be 86400 seconds 736 (one day). A one-time fetch of a profile can be accomplished by 737 setting the Expires parameter to 0 as defined in [RFC3265] resulting 738 in a single NOTIFY with no change notification. 740 7.5. NOTIFY Bodies 742 The size of profile content is likely to be hundreds to several 743 thousands of bytes in size. For this reason, if the Accept header of 744 the SUBSCRIBE included the MIME type message/external-body, 745 indicating support for content indirection, the profile delivery 746 server SHOULD use content indirection [I-D.ietf-sip-content-indirect- 747 mech] in the NOTIFY body for providing the profiles. 749 When delivering profiles via content indirection, the profile 750 delivery server MUST include the Content-ID MIME header described in 751 [I-D.ietf-sip-content-indirect-mech] for each profile URI. This is 752 to avoid unnecessary download of the profiles. Some user agents are 753 not able to make a profile effective without rebooting or restarting. 754 Rebooting is something to be avoided on a user agent performing 755 services such as telephony. By examining the Content-ID, the user 756 agent can recognize if it already has the indirected content, thus 757 avoiding unnecessary interruption of service. The Content-Type MUST 758 be specified for each URI. For minimal interoperability, the profile 759 delivery server MUST support the "http:" and "https:" URI schemes for 760 content indirection. Other URI schemes MAY also be provided in the 761 content indirection. However the security considerations are define 762 for content indirection using HTTP and HTTPS. Other protocols MAY be 763 supported for content indirection, but are out of scope of this 764 document. 766 Initially user agent implementers may use a proprietary content 767 type for the profiles retrieved from the URI(s). This is a good 768 first step towards easing the management of user agents. Standard 769 profile contents, content type and formats will need to be defined 770 for true interoperability of profile delivery. The specification 771 of the content is out of the scope of this document. 773 The URI scheme [RFC2396] used in content indirection may be dictated 774 by the profile content that is required. It is expected that FTP 775 [RFC0959], HTTP [RFC2616], HTTPS [RFC2818], LDAP [RFC3377], XCAP 776 [I-D.ietf-simple-xcap] and other URI schemes could be used by this 777 package and framework if the subscribing user agent and profile 778 delivery server both support the same scheme. The negotiation of the 779 URI scheme is described in the following sections. 781 7.6. Notifier processing of SUBSCRIBE requests 783 The general rules for processing SUBSCRIBE requests [RFC3265] apply 784 to this package. If content indirection is used for delivering the 785 profiles, the notifier does not need to authenticate the subscription 786 as the profile content is not transported in the SUBSCRIBE or NOTIFY 787 transaction messages. With content indirection, only URIs are 788 transported in the NOTIFY request which may be secured using the 789 techniques in Section 10. If content indirection is not used, the 790 subscribe server SHOULD reject SUBSCRIBE requests from connections 791 that are not over TLS and SHOULD challenge the SUBSCRIBE request with 792 SIP Digest authentication. The subscriber MUST support the "http:" 793 or "https:" URI scheme for content indirection. If the subscriber 794 wishes to use a URI scheme other than "http:", the subscriber must 795 use the "schemes" Contact header field parameter to indicate the URI 796 scheme as defined in [I-D.ietf-sip-content-indirect-mech]. For 797 example the subscriber may request that content indirection use the 798 "ldaps:" URI scheme by including "ldaps" in the "scheme" Contact 799 header parameter of the SUBSCRIBE request. If the subscriber does 800 not specify the URI scheme, the notifier may use either "http:" or 801 "https:". 803 The profile generation behavior of the profile delivery server is 804 left to the implementer. The profile delivery server may be as 805 simple as a SIP SUBSCRIBE UAS and NOTIFY UAC front end to a simple 806 HTTP server delivering static files that are hand edited. At the 807 other extreme the profile delivery server can be part of a 808 configuration management system that integrates with a corporate 809 directory and IT system or carrier operations support systems, 810 where the profiles are automatically generated. The design of 811 this framework intentionally provides the flexibility of 812 implementation from simple/cheap to complex/expensive. 814 The "profile-type" parameter can be thought of as a filter to 815 indicate which profile(s) are to be provided. If the profile type 816 indicated in the "profile-type" Event header parameter is not 817 provisioned or provided to any users in the domain, the profile 818 delivery server the Notifier SHOULD return a 404 responce to the 819 SUBSCRIBE request. 821 If the specific user or device is not known to the profile delivery 822 server, the implementer MAY accept the subscription or reject it. It 823 is a policy decision whether to maintain the subscription dialog for 824 an unprovisioned user or device. It is recommended that the 825 implementer accept the subscription. It is useful for the profile 826 delivery server to maintain the subscription for unprovisioned users 827 or devices as an administrator may add the user or device to the 828 system after the initial subscription, defining the profile contents. 829 This allows the profile delivery server to immediately send a NOTIFY 830 request with the profile URIs. If the profile delivery server does 831 not accept the subscription from an unknown user or device, the 832 administer or user must manually provoke the user agent to re- 833 subscribe. This may be difficult if the user agent and administrator 834 are at different locations. 836 A user agent can provide hotelling by collecting a user's AOR and the 837 credentials needed to SUBSCRIBE and retrieve the user's profiles. 838 Hotelling functionality is achieved by subscribing to the user's AOR 839 and specifying the "user" profile type. This same mechanism can also 840 be used to secure a user agent, requiring a non-mobile user to login 841 to enable functionality beyond the default user's restricted 842 functionality. 844 When the Event header "profile-type" is "device" and the user agent 845 has provided the user's AOR in the "network-user" parameter, the 846 profile delivery server MAY set or change the default user associated 847 with the device indicated in the SUBSCRIBE URI. This is an 848 implementation or policy decision. The profile delivery server 849 SHOULD authenticate the user for the SUBSCRIBE request before 850 changing the default user associated with the device. 852 7.7. Notifier generation of NOTIFY requests 854 As in [RFC3265], the profile delivery server MUST always send a 855 NOTIFY request upon accepting a subscription. If the device or user 856 is unknown to the profile delivery server and it chooses to accept 857 the subscription, the implementer has two choices. A NOTIFY MAY be 858 sent with no body or content indirection containing the profile 859 URI(s). Alternatively, a NOTIFY MAY be sent with a body or content 860 indirection containing URI(s) pointing to a default data set. The 861 data sets provided may allow for only limited functionality of the 862 user agent (e.g. a telephony user agent that only permits calls to 863 the help desk and emergency services). This is an implementation and 864 business policy decision for the profile delivery server. 866 If the URI in the SUBSCRIBE request is a known identity and is 867 provisioned with the requested profile type (i.e. as specified in the 868 profile-type parameter of the Event header), the profile delivery 869 server SHOULD send a NOTIFY with profile data or content indirection 870 (if the content indirection mime type was included in the Accept 871 header) containing the URI for the profile. To protect the integrity 872 of the profile data or indirect content profile data URIs, the 873 notifier SHOULD send the NOTIFY request on the same TLS connection as 874 the SUBSCRIBE request came in on if TLS was used. 876 The profile delivery server may specify when the new profiles must be 877 made effective by the user agent. The profile delivery server MAY 878 specify a maximum time in seconds (zero or more) in the 879 "effective-by" event header parameter. The user agent uses the 880 "effective-by" parameter to determine when to make the new profiles 881 effective for all dialogs. 883 7.8. Subscriber processing of NOTIFY requests 885 The user agent subscribing to this event package MUST adhere to the 886 NOTIFY request processing behavior specified in [RFC3265]. The user 887 agent MUST attempt to make the profiles effective within the time in 888 seconds given in the "effective-by" Event header parameter if present 889 in the NOTIFY request (see Section 7.7). By default, the user agent 890 makes the profiles effective as soon as it thinks that it is non- 891 obtrusive to do so. For example, when there are no active calls. 892 Profile changes SHOULD affect behavior on all new dialogs which are 893 created after the notification, but may not be able to affect 894 existing dialogs. The user agent SHOULD use one of the techniques 895 specified in Section 10 to securely retrieve the profiles. If the 896 subscriber included the MIME type message/external-body for content 897 indirection in the SUBSCRIBE request Accept header, the subscriber 898 MUST support the http: or https: URI schemes for content indirection. 899 If the subscriber indicated alternative URI schemes for content 900 indirection it MUST also indicate support for http: or https:. The 901 subscriber should still be prepared to use http: or https: as the 902 profile delivery server may not support the alternative URI schemes. 904 The subscriber MUST be prepared to receive a NOTIFY request with no 905 body. The subscriber MUST NOT reject the NOTIFY request with no 906 body. The subscription dialog MUST NOT be termnated by the NOTIFY 907 with no body. 908 The subscriber should maintain the dialog as it was the profile 909 delivery server's policy decision to create the dialog. Most 910 likely the NOTIFY body is empty because the user or device is not 911 provisioned in the profile delivery server. The notifier decided 912 to maintain the dialog so that it can NOTIFY the subscribe of the 913 availablity of the profile immediately after the user or device 914 gets provisioned. If the subscriber ended the dialog after 915 receiving the NOTIFY with no body, the subscriber would need to be 916 manually provoked to resubscribe. 918 7.9. Handling of forked requests 920 This event package allows the creation of only one dialog as a result 921 of an initial SUBSCRIBE request. The techniques to achieve this are 922 described in section 4.4.9 of [RFC3265]. 924 7.10. Rate of notifications 926 It is anticipated that the rate of change for user and device 927 profiles will be very infrequent (i.e. days or weeks apart). For 928 this reason no throttling or minimum period between NOTIFY requests 929 is specified for this package. 931 7.11. State Agents 933 State agents are not applicable to this event package. 935 7.12. Examples 937 Example SUBSCRIBE and NOTIFY request using content indirection: Note: 939 The Event and Via header fields are continued on a second line due to 940 format constraints of this document. 942 SUBSCRIBE sip:MAC%3aFF00000036C5@acme.example.com SIP/2.0 943 Event: ua-profile;profile-type=device;vendor="vendor.example.com"; 944 model="Z100";version="1.2.3";network-user="sip:betty@example.com" 945 From: sip:MAC%3aFF00000036C5@acme.example.com;tag=1234 946 To: sip:MAC%3aFF00000036C5@acme.example.com 947 Call-ID: 3573853342923422@10.1.1.44 948 CSeq: 2131 SUBSCRIBE 949 Contact: sip:MAC%3aFF00000036C5@10.1.1.44 950 Via: SIP/2.0/TCP 10.1.1.41; 951 branch=z9hG4bK6d6d35b6e2a203104d97211a3d18f57a 952 Accept: message/external-body, application/x-z100-device-profile 953 Content-Length: 0 955 NOTIFY sip:MAC%3aFF00000036C5@10.1.1.44 SIP/2.0 956 Event: ua-profile;effective-by=3600; 957 network-user="sip:betty@example.com" 958 From: sip:MAC%3aFF00000036C5@acme.example.com;tag=abcd 959 To: sip:MAC%3aFF00000036C5@acme.example.com;tag=1234 960 Call-ID: 3573853342923422@10.1.1.44 961 CSeq: 321 NOTIFY 962 Via: SIP/2.0/UDP 192.168.0.3; 963 branch=z9hG4bK1e3effada91dc37fd5a0c95cbf6767d1 964 MIME-Version: 1.0 965 Content-Type: multipart/mixed; boundary=boundary42 966 Content-Length: ... 968 --boundary42 969 Content-Type: message/external-body; 970 access-type="URL"; 971 expiration="Mon, 24 June 2002 09:00:00 GMT"; 972 URL="http://www.example.com/devices/ff00000036c5"; 973 size=1234 975 Content-Type: application/x-z100-device-profile 976 Content-ID: <39EHF78SA@example.com> 978 --boundary42-- 980 7.13. Use of URIs to Retrieve State 982 The URI for the SUBSCRIBE request is formed differently depending 983 upon which profile type the subscription is for. This allows the 984 different profile types to be potentially managed by different 985 profile delivery servers (perhaps even operated by different 986 entities). The To and From field will typically contain the same URI 987 as is used in the original SUBSCRIBE request URI. 989 7.13.1. Device URIs 991 The URI for the "device" type profile (device URI) is based upon the 992 identity of the device. The device URI MUST be unique across all 993 devices and implementations. If an instance id is used as the user 994 part of the device URI, it SHOULD remain the same for the lifetime of 995 the user agent. The device URI is used to identify which profile is 996 associated with a specific instance of a user agent. 998 If the user agent changed its device URI, the profile delivery 999 server would not know the association between the profile and the 1000 device. This would also make it difficult for the profile 1001 delivery server to track user agents under profile management. 1002 The profile delivery server may decide to provide the same device 1003 profile to all devices of the same vendor, model and version. 1004 However this is a implementation choice of the profile delivery 1005 server. The subscribing device has no way of knowing whether the 1006 profiles for each device are different. For this reason the 1007 device must always use a unique id in the device SUBSCRIBE request 1008 URI. As an example the device profile for similar devices may 1009 differ with properties such as the default user. This is how the 1010 bootstrapping mechanism works as described in Section 8.1.3. 1012 The URI for the device type profile MUST use a unique identifier as 1013 the user portion of the URI. The host and port portion of the URI is 1014 set to that of the domain or address of the profile delivery server 1015 which manages that user agent. A means of discovering the host and 1016 port portion is discussed in Section 8.1. There is an administration 1017 aspect of the unique identifier, that makes it desirable for the id 1018 to be obtainable or predictable prior to installation of the device 1019 (hard or soft). Also from a human factors perspective, ids that are 1020 easily distinguished and communicated will make the administrators 1021 job a little easier. The MAC address or a UUID [RFC4122] SHOULD be 1022 used for constructing a unique identifier to be used in the user 1023 portion of the device URI. 1025 If the identifier is a MAC address, it MUST be formatted as the 1026 characters "MAC:" followed by a 12 digit hexadecimal representation 1027 of the MAC address. The address can not include ":", whitespace, or 1028 other formatting. 1030 The MAC address of the device may be used if there will always be 1031 no more than one user agent using that MAC address over time (e.g. 1032 a dedicated telephone appliance). The MAC address may not be used 1033 if more than one user agent instance exists using the same MAC 1034 address (e.g. multiple instances of a softphone may run on a 1035 general purpose computing device). The advantage of the MAC 1036 address is that many vendors put bar codes on the device with the 1037 actual MAC address on it. A bar code scanner is a convenient 1038 means of collecting the instance id for input and provisioning on 1039 the profile delivery server. If the MAC address is used, it is 1040 recommended that the MAC address is rendered in all upper case 1041 with no punctuation for consistency across implementations. A 1042 prefix of "MAC:" should be added to the MAC address to form a 1043 proper URN [RFC2141]. For example a device managed by 1044 sipuaconfig.example.com using its MAC address to form the device 1045 URI might look like: 1046 sip:MAC%3a00DF1E004CD0@sipuaconfig.example.com. 1048 UHEX = DIGIT / %x41-46 ;uppercase A-F 1049 MAC = %x4d.41.43 ; MAC in caps 1050 mac-ident = MAC ":" 12UHEX 1052 When the MAC address is not used in the device URI, a UUID [RFC4122] 1053 for the device SHOULD be used. 1055 For devices where there is no MAC address or the MAC address is 1056 not unique to an instance of a user agent (e.g. multiple 1057 softphones on a computer or a gateway with multiple logical user 1058 agents) it is RECOMMENDED that a UUID [RFC4122] is used as the 1059 user portion of the device URI. The same approach to defining a 1060 user agent instance ID as [I-D.ietf-sip-outbound] should be used. 1061 When constructing the instance id, the implementer should also 1062 consider that a human may need to manually enter the instance id 1063 to provision the device in the profile delivery server (e.g. 1064 longer strings are more error prone in data entry). When the URN 1065 is used as the user part of the URI, it MUST be URL escaped. The 1066 ":" is not a legal character (without being escaped) in the user 1067 part of a addr-spec [RFC4122]. For example the instance ID: 1068 urn:uuid:f81d4fae-7ced-11d0-a765-00a0c91e6bf6 would be escaped to 1069 look as follows in a URI: 1070 sip:urn%3auuid%3af81d4fae-7ced-11d0-a765-00a0c91e6bf6@example.com. 1071 Soft user agents are likely to need to use this approach due to 1072 the multi-user nature of general purpose computers. The software 1073 installer program might generate the uuid as part of the install 1074 process so that it remains persistent for the installation. It 1075 may also be desirable that any upgrades of the software maintain 1076 the unique id. However these are all implementation choices. 1078 7.13.2. User URIs 1080 The URI for the "user" type profile is based upon the identity of the 1081 user. It is an administration policy on how user profile identities 1082 are assigned. Typically the user's address of record (AOR) is used 1083 as the URI in the SUBSCRIBE request. A new user agent or device may 1084 not know the user's AOR. The user's AOR may be obtained as part of a 1085 default user property in the device profile. Alternatively the user 1086 agent may prompt the user for an AOR and credentials to be used to 1087 authenticate the request. This can provide a login and/or hotelling 1088 feature on the user agent. The user agent may be pre-provisioned 1089 with the user's AOR or provided as information on a SIM or flash key. 1090 These are only examples and not an exhaustive list of sources for the 1091 user AOR. 1093 7.13.3. Local Network URIs 1095 The URI for the "local-network" type profile is based upon the 1096 identity of the local network. When subscribing to the local network 1097 profile, the user part of the SUBSCRIBE request URI SHOULD NOT be 1098 provided. The From field user part of the SUBSCRIBE request SHOULD 1099 be the same device ID used as the user part of the device profile 1100 SUBSCRIBE request URI defined in Section 7.13.1. The host and port 1101 part of the request URI and From field is the local network name/ 1102 domain. The discovery of the local network name or domain is 1103 discussed in Section 8.1. The user agent may provide the user's AOR 1104 as the value to the "network-user" event header parameter. This is 1105 useful if the user has privileges in the local network beyond those 1106 of the default user. When "network-user" is provided the profile 1107 delivery server SHOULD authenticate the user before providing the 1108 profile if additional privileges are granted. Example URI: sip: 1109 example.com 1111 The local network profile SUBSCRIBE request URI does not have a 1112 user part so that the URI is distinct between the "local" and 1113 "device" URIs when the domain is the same for the two. This 1114 provides a means of routing to the appropriate profile delivery 1115 server in domains where they are distinct servers. The From field 1116 uses the device ID in the user part of the local network request 1117 URI so that every device in the network has a unique and constant 1118 From field. Even though every device may get the same or similar 1119 local network profiles, the uniqueness of the From field provides 1120 an important capability. Having unique From fields allows the 1121 management of the local network to track user agents present in 1122 the network and consequently also manage resources such as 1123 bandwidth and port allocation. 1125 8. Profile Delivery Framework Details 1127 The following describes how different functional steps of the profile 1128 delivery framework work. Also described here is how the event 1129 package defined in this document provides the enrollment and 1130 notification functions within the framework. 1132 8.1. Discovery of Subscription URI 1134 The discovery approach varies depending upon which profile type URI 1135 is to be discovered. The order of discovery is important in the 1136 bootstrapping situation as the user agent may not have any 1137 information provisioned. The local network profile should be 1138 discovered first as it may contain key information such as how to 1139 traverse a NAT/firewall to get to outside services (e.g. the user's 1140 profile delivery server). The device profile URI should be 1141 discovered next. The device profile may contain the default user's 1142 AOR or firmware/software information that should be updated first 1143 before proceeding with the discovery process. The user profile 1144 subscription URI should be discovered last. The URIs are formed 1145 differently for each of the profile types. This is to support the 1146 delegation of the profile management to potentially three different 1147 entities. However all three profile types may be provided by the 1148 same entity. As the user agent has no way of knowing whether the 1149 profiles are provide by one or more different profile delivery 1150 servers ahead of time, it must subscribe to all three profile types 1151 in separate SUBSCRIBE requests to get the profiles. 1153 8.1.1. Discovery of Local Network URI 1155 The "discovered" host for the "local-network" profile subscription 1156 URI is the local IP network domain for the user agent, either 1157 provisioned as part of the device's static network configuration or 1158 discovered via DHCP [RFC2131](option 15 [RFC2132]). The local 1159 network profile subscription URI SHOULD not be remembered if the user 1160 agent moves from one local network to another other. The user agent 1161 should perform the local network discovery to construct the network 1162 profile subscription request URI every time it starts up or network 1163 connectivity is regained. 1165 For example: The user agent requested and received the local 1166 domain name via DHCP: airport.example.net. If the device ID is: 1167 MAC:00DF1E004CD0, the local network profile SUBSCRIBE request URI 1168 would look like: sip:MAC%3a00DF1E004CD0@airport.example.net. The 1169 user agent should send this request using the normal SIP locating 1170 mechanisms defined in [RFC3263]. The Event header would look like 1171 the following if the user agent decided to provide 1172 sip:alice@example.com as the user's AOR. (Alice may have a prior 1173 arrangement with the local network operator giving her special 1174 privileges.): 1176 Event: ua-profile;profile-type=local-network; 1177 network-user="sip:alice@example.com" 1179 8.1.2. Discovery of Device URI 1181 The discovery function is needed to bootstrap user agents to the 1182 point of knowing where to enroll with the profile delivery server. 1183 Section 7.13.1 describes how to form the user part of the device 1184 profile SUBSCRIBE request URI used for enrollment. However the 1185 bootstrapping problem for the user agent (out of the box) is what to 1186 use for the host and port in the device URI. Due to the wide 1187 variation of environments in which the enrolling user agent may 1188 reside (e.g. behind residential router, enterprise LAN, WLAN hotspot, 1189 ISP, dialup modem) and the limited control that the administrator of 1190 the profile delivery server (e.g. enterprise, service provider) may 1191 have over that environment, no single discovery mechanism works 1192 everywhere. 1194 Therefore a number of mechanisms should be tried in the specified 1195 order: SIP DHCP option [RFC3361], SIP DNS SRV [RFC3263], DNS A record 1196 and manual. The user agent may be pre-provisioned with the host and 1197 port (e.g. service providers may pre-provision a device before 1198 sending it to a subscriber, provide a SIM or flash key, etc.) in 1199 which case this discovery mechanism is not needed. Before performing 1200 the discovery steps, the user agent should provide a means to skip 1201 the discovery stage and manually enter the device URI host and port. 1202 In addition, the user agent should allow the user to accept or reject 1203 the discovered host and port in case an alternative to the discovered 1204 host and port is desired. 1206 1. The first discovery mechanism for the device SUBSCRIBE request 1207 URI Section 7.13.1 is to use the host and port of the outbound 1208 proxy discovered by the SIP DHCP option 120 [RFC3361]. If the 1209 SIP DHCP option is not provided in the DHCP response or if the 1210 SUBSCRIBE request to the ua-profile event receives no response or 1211 a failure response other than for authentication, the next 1212 discovery mechanism should be tried. 1214 For example: Consider a dedicated hardware device with a 1215 single user agent having the MAC address: abc123efd456. The 1216 user agent sends a DHCP request including the request for the 1217 DHCP option for SIP: 120 (see [RFC3361]). If the DHCP 1218 response includes an answer for option 120, then the DNS name 1219 or IP address included is used in the host part of the device 1220 URI. For this example let's assume: example.com. The device 1221 URI would look like: sip:MAC%3aABC123EFD456@example.com. The 1222 user agent should send this request using the normal SIP 1223 locating mechanisms defined in [RFC3263]. If the response 1224 fails then, the next discovery mechanism is tried. 1226 2. The local IP network domain for the user agent, either configured 1227 or discovered via DHCP option 15, should be used with the 1228 technique in [RFC3263] to obtain a host and port to use in the 1229 SUBSCRIBE URI. If no SIP response or a SIP failure response 1230 other than for authorization is received for the SUBSCRIBE 1231 request to the ua-profile event, the next discovery mechanism 1232 should be tried. 1234 For example: The user agent requested and received the local 1235 domain name (option 15 [RFC2132]) in the DHCP response: 1236 boston.example.com. The device URI would look like: 1237 sip:MAC%3aABC123EFD456@boston.example.com. The user agent 1238 should send this request using the normal SIP locating 1239 mechanisms defined in [RFC3263]. If the response fails then, 1240 the next discovery mechanism is tried. 1242 3. The fully qualified host name constructed by concatenating 1243 "sipuaconfig" and the local IP network domain (as provided via 1244 DHCP option 15 or provisioned) should be tried next using the 1245 technique in [RFC3263] to obtain a host and port to use in the 1246 SUBSCRIBE URI. If no SIP response or a SIP failure response 1247 other than for authorization is received for the SUBSCRIBE 1248 request to the ua-profile event, the next discovery mechanism 1249 should be tried. 1251 For example: The user agent requested and received the local 1252 domain name via DHCP as in the above example: 1253 boston.example.com. The device URI would look like: 1254 sip:MAC%3aABC123EFD456@sipuaconfig.boston.example.com. The 1255 user agent should send this request using the normal SIP 1256 locating mechanisms defined in [RFC3263]. If the response 1257 fails then, the next discovery mechanism is tried. 1259 4. If all other discovery techniques fail, a manual means for the 1260 user to enter the host and port used to construct the SUBSCRIBE 1261 request URI MUST be provided by the user agent. 1263 Two approaches to the manual discovery process are suggested. In the 1264 first approach using SIP, the user agent provides a means for 1265 entering the subscription host and port information for the request 1266 URI along with the user id and password to be used for authentication 1267 of the SUBSCRIBE request. With this approach the user agent begins 1268 with the enrollment process followed by the change notification and 1269 profile retrieval steps. 1271 An alternative to the manual discovery using SIP, is to start with 1272 the retrieve process. The user agent provides a means of entering a 1273 HTTPS URI along with the user id and password to be used for 1274 authentication of the retrieval of the profile. The retrieved device 1275 profile may contain the properties for the SUBSCRIBE request URI and 1276 credentials to enroll and get change notification of profile changes. 1277 This approach bootstraps the process in a different step in the 1278 cycle, but uses the same profile framework. When the device starts 1279 with retrieval of the profile via HTTPS (instead of a SIP SUBSCRIBE 1280 to the event package), the device MUST provide the Event header in 1281 the HTTPS request using the same format as described for the 1282 SUBSCRIBE request (see Section 7.2) . The Event header is necessary 1283 to determine which profile is requested as well as for providing 1284 specific information about the device. 1286 This document defines a new HTTP request header "Event". The syntax 1287 of the HTTP Event header is the same as the SIP Event header defined 1288 in this document. The purpose of the HTTP Event header, just like 1289 the SIP Event header is to define the content of the state 1290 information to be retrieved. In particular, the state information is 1291 the device, user or local network profile for the device. The SIP 1292 Event header parameters for this event package ("profile-type", 1293 "vendor", "model", "version") are also manditory for the HTTP Event 1294 header as they are used to provide information as to what profile 1295 type is requested along with information about the device which may 1296 impact the contents of the profile. 1298 Once a user agent has been successfully discovered, enrolled and 1299 received a NOTIFY response with profile data or URI(s), the user 1300 agent should cache (i.e. store persistently) the device profile 1301 SUBSCRIBE request URI (rather than reconstructing it as described in 1302 the discovery process every time the device is restarted) to avoid 1303 having to rediscover the profile delivery server again in the future. 1304 Caching of the device URI is necessary when the user agent is likely 1305 to move to different local network domains as the local network may 1306 not be the provider for the device's profile. The user agent should 1307 not cache the device URI until it receives a NOTIFY with profile data 1308 or URI(s). The reason for this is that a profile delivery server may 1309 send 202 responses to SUBSCRIBE requests and NOTIFY responses to 1310 unknown user agent (see Section 7.6) with no profile data or URIs. 1311 Until the profile delivery server has sent a NOTIFY request with 1312 profile data or URI(s), it has not agreed to provide profiles. 1314 To illustrate why the user agent should not cache the device 1315 profile SUBSCRIBE URI until profile data or URI(s) are provided in 1316 the NOTIFY, consider the following example: a user agent running 1317 on a laptop plugged into a visited LAN in which a foreign profile 1318 delivery server is discovered. The profile delivery server never 1319 provides profile URIs in the NOTIFY request as it is not 1320 provisioned to accept the user agent. The user then takes the 1321 laptop to their enterprise LAN. In this example, the user agent 1322 cached the SUBSCRIBE URI from the visited LAN which did not 1323 provide profiles. When the UA is subsequently placed in the 1324 enterprise LAN which is provisioned to provide profiles to the 1325 user agent, the user agent would not attempt to discover the 1326 profile delivery server. 1328 8.1.3. Discovery of User URI 1330 The user's AOR may be pre-provisioned or provided via SIM or flash 1331 key, etc. The device profile may define a default user and AOR. If 1332 provided in the device profile and a pre-provisioned user AOR is not 1333 provided, the default user's AOR is used to subscribe to the "user" 1334 profile. If not provided through the above two approaches, the AOR 1335 to be used for the "user" subscription URI, is "discovered" manually 1336 by prompting the user. The URI obtained in the discovery steps 1337 described above for the "user" profile subscription is stored 1338 persistently in the device until explicitly reset or updated by the 1339 user or profile. 1341 8.2. Enrollment with Profile Server 1343 Enrollment is accomplished by subscribing to the event package 1344 described in Section 7. The enrollment process is useful to the 1345 profile delivery server as it makes the server aware of user agents 1346 to which it may deliver profiles. These include user agents that the 1347 profile delivery server is provisioned to provide profiles to, those 1348 present to which the server may provide profiles in the future, and 1349 those that the server can automatically provide default profiles. It 1350 is an implementation choice and business policy as to whether the 1351 profile delivery server provides profiles to user agents that it is 1352 not explicitly provisioned to do so. However the profile delivery 1353 server SHOULD accept (with 2xx response) SUBSCRIBE requests from any 1354 user agent as explained in Section 7.5. 1356 8.3. Notification of Profile Changes 1358 The NOTIFY request in the ua-profile event package serves two 1359 purposes. First it provides the user agent with a means to obtain 1360 the profile data directly or via URI(s) for desired profiles without 1361 requiring the end user to manually enter them. It also provides the 1362 means for the profile delivery server to notify the user agent that 1363 the content of the profiles has changed and should be made effective. 1364 Optionally the differential changes may be obtained by notification 1365 by including the content-type: "application/xcap-diff+xml" defined in 1366 [I-D.ietf-simple-xcap-diff] in the Accept header of the SUBSCRIBE 1367 request. 1369 8.4. Retrieval of Profile Data 1371 The user agent retrieves its needed profile(s) directly or via the 1372 URI(s) provided in the NOTIFY request as specified in Section 7.5. 1373 The profile delivery server SHOULD secure the content of the profiles 1374 using one of the techniques described in Section 10. The user agent 1375 SHOULD make the new profiles effective in the timeframe described in 1376 Section 7.2. 1378 The contents of the profiles SHOULD be cached (i.e. stored 1379 persistently) by the user agent. The cache should be used if the 1380 user agent is unable to successfully SUBSCRIBE or receive the NOTIFY 1381 providing the most recent profile. The cached profile should be 1382 replaced each time a profile is received in a NOTIFY or retrieved via 1383 content indirection. This it to avoid the situation where the 1384 content delivery server being not available, leaves the user agent 1385 non-functional. The user agent should verify that it has the latest 1386 profile content using the "hash" parameter defined in [I-D.ietf-sip- 1387 content-indirect-mech]. 1389 8.5. Upload of Profile Changes 1391 The user agent or other service MAY push changes up to the profile 1392 delivery server using the technique appropriate to the profile's URI 1393 scheme (e.g. HTTP PUT method, FTP put command). The technique for 1394 pushing incremental or atomic changes MUST be described by the 1395 specific profile data framework. A means for pushing changes up into 1396 the profile delivery server for XCAP is defined in [I-D.ietf-simple- 1397 xcap]. 1399 9. IANA Considerations 1401 There are several IANA considerations associated with this 1402 specification. 1404 9.1. SIP Event Package 1406 This specification registers a new event package as defined in 1407 [RFC3265]. The following information required for this registration: 1409 Package Name: ua-profile 1410 Package or Template-Package: This is a package 1411 Published Document: RFC XXXX (Note to RFC Editor: Please fill in 1412 XXXX with the RFC number of this specification). 1413 Person to Contact: Daniel Petrie dan.ietf AT SIPez DOT com 1414 New event header parameters: profile-type, vendor, model, version, 1415 effective-by, network-user 1416 The profile-type parameter has predefined values. The other new 1417 event header parameters do not. 1418 The following table illustrates the additions to the IANA SIP Header 1419 Field Parameters and Parameter Values: (Note to RFC Editor: Please 1420 fill in XXXX with the RFC number of this specification) 1422 Predefined 1423 Header Field Parameter Name Values Reference 1424 ---------------------------- --------------- --------- --------- 1425 Event profile-type Yes [RFCXXXX] 1426 Event vendor No [RFCXXXX] 1427 Event model No [RFCXXXX] 1428 Event version No [RFCXXXX] 1429 Event effective-by No [RFCXXXX] 1430 Event network-user No [RFCXXXX] 1432 9.2. New HTTP Event Header 1434 This document defines a new permanent HTTP request header field: 1435 Event 1437 Header field name: Event 1438 Applicable protocol: http 1439 Status: standard 1440 Author/Change controller: IETF 1441 Specification document(s): [RFCXXXX] (Note to RFC Editor: Please 1442 fill in XXXX with the RFC number of this specification). 1444 10. Security Considerations 1446 Profiles may contain sensitive data such as user credentials and 1447 personal information. The protection of this data depends upon how 1448 the data is delivered. Some profiles may be safe to deliver without 1449 the need to protect the content. For example in some environments 1450 the local network profile may contain the list of codecs that are 1451 acceptable for use in the network and information on NAT traversal 1452 such as a STUN server to use. As the information in this example 1453 local network profile does not contain passwords or sensitive 1454 information it may be acceptable to provide it without authentication 1455 or confidentiality (encryption). We refer to these as non- 1456 confidential profiles. Non-confidential profiles require message 1457 integrity and profile server authentication, as described in 1458 Section 10.3. However any profiles that contain personal 1459 information, passwords or credentials (confidential profiles) require 1460 mutual authentication, confidentiality, and message integrity, and 1461 must follow the guidance provided in the next two subsections. 1462 Profile specifications that define schemas MUST identify if they 1463 contain confidential data to indicate which of the security 1464 approaches described here should be used. 1466 The profile data is delivered in either the NOTIFY request or via the 1467 URI scheme indicated in the content indirection in the NOTIFY 1468 request. The security approach is different for these two delivery 1469 mechanisms. 1471 Subscribers implementing this specification MUST implement either 1472 HTTP or HTTPS. Subscribers also MUST implement the hash verification 1473 scheme described in SIP content indirection [I-D.ietf-sip-content- 1474 indirect-mech]. SIP profile delivery servers MUST implement both 1475 HTTP and HTTPS, and SHOULD implement a SIP Authentication Service as 1476 described in the SIP Identity mechanism [I-D.ietf-sip-identity]. All 1477 SIP entities are already required to implement SIP Digest 1478 authentication [RFC3261]. 1480 10.1. Confidential Profile Content in NOTIFY Request 1482 When the profile data is delivered directly in the NOTIFY request, 1483 the SUBSCRIBE request MUST be authenticated using the SIP Digest 1484 authentication mechanism. As the profile content is delivered in the 1485 resulting NOTIFY request to the subscription, authenticating the 1486 SUBSCRIBE is the only way to prevent unauthorized access to the 1487 profile data. To provide message integrity and confidentiality over 1488 the profile data, a direct TLS connection MUST be established for the 1489 SUBSCRIBE request. The device SHOULD authenticate the server via the 1490 TLS connection, which also provides a means of verifying (as 1491 described in [RFC3261]) that a direct TLS connection was used (e.g. 1492 The device may prompt the user to verify the SubjectAltName in the 1493 server's certificate.). The server may challenge the device for its 1494 certificate, when establishing the TLS connection, to obtain the 1495 public key to use to S/MIME encode the NOTIFY request body containing 1496 the profile data. Because the device verified that it has a direct 1497 TLS connection by verifying the server's certificate and the server 1498 verified the identity of the device using Digest Authentication, the 1499 server can assume the certificate provided by the device is 1500 authenticated. The use of S/MIME in the NOTIFY request does not 1501 relieve the need to authenticate the SUBSCRIBE request using SIP 1502 Digest authentication. In this scenario S/MIME only provides message 1503 integrity and confidentiality of the content of the profile. If 1504 S/MIME is not used for the profile data in the NOTIFY request, the 1505 notifier MUST use the same direct TLS connection established by the 1506 device for the SUBSCRIBE request to send the notification. In this 1507 scenario the use of a user-specific ID and secret for Digest 1508 Authentication can be used to establish an association between the 1509 user ID and the device ID provided in the device profile SUBSCRIBE 1510 request. 1512 10.2. Confidential Profile Content via Content Indirection 1514 When the profile data is delivered via content indirection, 1515 authentication, integrity, confidentiality are all provided in the 1516 profile indirection retrieval scheme. When content indirection is 1517 used, the SUBSCRIBE request does not need to be authenticated. There 1518 is a TLS certificate approach and a Digest Authentication approach 1519 which may be used to provide the required security. The profile 1520 delivery server MUST support both of these methods. The device MUST 1521 support the Digest Authentication method to provide minimal 1522 interoperability. 1524 For the TLS certificate approach, the device requests the profile 1525 using HTTPS. To provide authentication, the server challenges the 1526 device for its certificate. The server obtains the user part of the 1527 SIP URI in the Subject Alternative Name field of the device's 1528 certificate. The user part of the SIP URI in the device's 1529 certificate is used as the device ID to authenticate if the device is 1530 authorized to retrieve the specified profile. The device 1531 certificates chain of authorities MUST also be verified. This 1532 approach for providing security requires that the device ID and 1533 associated user are provisioned for authentication as part of the 1534 content indirection retrieval. 1536 For the Digest Authentication approach, HTTPS SHOULD be used to 1537 provide confidentiality of the profile data. HTTP Digest 1538 Authentication [RFC2617] MUST be used to authenticate and authorize 1539 the device to retrieve the profile. The shared secret used in the 1540 Digest Authentication is provided through out of band means to the 1541 device or user of the device. The same credentials used for SIP 1542 Digest authentication (e.g. authentication of SIP SUBSCRIBE and 1543 REGISTER requests) are used in the HTTPS request. Other URI schemes 1544 may be used, but are not defined in this document. A non-replayable 1545 authentication mechanism such as Digest authentication MUST be used 1546 for the content indirection URI scheme which provides the profile 1547 data (e.g. LDAP, HTTP and HTTPS all support Digest authentication). 1548 URI schemes which provide no authentication or only clear-text 1549 authentication SHOULD NOT be used for profile delivery as they are 1550 vulnerable to replay attacks (e.g. TFTP does not provide 1551 authentication). 1553 Without a suitable authentication mechanism, the content 1554 indirection profile delivery URI scheme is susceptible to replay 1555 attacks. Even if the profile is symmetrically encrypted, if it 1556 can be retrieved through a replay attack, the encrypted profile 1557 can be used for offline attacks to crack the encryption key. 1559 The profile delivery scheme MUST use channel security such as TLS 1560 (e.g. HTTPS) to protect the content from being snooped in transport 1561 to the user agent. Mutual authentication using the client and server 1562 certificates MAY be used to verify the authenticity of the user or 1563 device identity and the profile delivery server identity. The user 1564 agent SHOULD provide a mechanism for the user to approve the 1565 SUBSCRIBE server identity or provision the acceptable server identity 1566 through out of band means. 1568 10.3. Integrity protection for non-confidential profiles 1570 Even for non-confidential profiles, the subscriber MUST verify the 1571 authenticity of the profile delivery server, and MUST verify that the 1572 integrity of the profile data and content indirection URI, if one is 1573 provided. To meet these requirements in the SIP messaging the NOTIFY 1574 request MUST use a SIP Identity header [I-D.ietf-sip-identity], or 1575 S/MIME. If content is provided via redirection, the content 1576 indirection "hash" parameter MUST be included unless the profile data 1577 is delivered via a protocol which natively provides authentication 1578 and message integrity, such as HTTP or LDAP protected by TLS. The 1579 content retrieved via the content indirection URI MUST be integrity 1580 checked using the "hash" parameter. 1582 For example, Alice subscribes to the local domain profile for 1583 paris.example.com. She receives a NOTIFY request which uses content 1584 indirection, including a "hash" parameter. Alice uses the Identity 1585 header from the NOTIFY to verify that the request came from 1586 paris.example.com and that the body was not modified. Then she 1587 fetches the content at the provided URI and verifies that the hash 1588 she calculates from the profile matches the hash provided in the SIP 1589 signaling. 1591 10.4. Initial Enrollment Using a Manufacturer's Certificate 1593 A UA with a manufacturer certificate can use this certificate for 1594 initial enrollment into the configuration framework. In order to 1595 safely deploy this scenario, the profile delivery server MUST 1596 maintain a list of enrolled devices and a separate list of devices 1597 which it expects to enroll. 1599 When the device sends a subscription request to the notifier, the 1600 notifier extracts the device-id from the user part of the Request URI 1601 and checks if the device is expected to enroll. If the device is 1602 expected, the notifier provides an https: URL to the subscriber and 1603 uses the SIP Identity mechanism to protect the integrity of this URL. 1604 This URL MUST contain enough information that the profile content 1605 server can correlate a request to this URL with the device-id that 1606 was in the subscription. 1608 The subscriber then establishes a TLS connection to the profile 1609 content server and performs ordinary authentication of the server 1610 certificate. During the TLS handshake, the profile content server 1611 requests the certificate of the subscriber. The subscriber provides 1612 its device certificate. Typically this certificate is created by the 1613 manufacturer of the device. If no client certificate is provided, 1614 the profile content server SHOULD return a 403 Forbidden response. 1616 Next the profile content server checks the client certificate 1617 according to the following steps: 1618 1. The client certificate MUST be valid, and MUST be rooted in a 1619 certificate authority that the administrator of the profile 1620 content server trusts to assert a valid "enrollment identity", 1621 for example a MAC address, serial number, or device-id. 1622 2. The profile content server MUST verify that the device-id 1623 provided in the https: URL corresponds to the subject or 1624 subjectAltName of the client certificate, in an implementation 1625 specific way. For example, the profile content server could 1626 extract the MAC address from the device-id and the certificate 1627 and compare them. How device certificates are arranged is not 1628 standardized at the time of this writing, and is outside the 1629 scope of this document. 1630 3. The profile content server SHOULD verify that the issuer of the 1631 certificate is expected and authorized to assert an enrollment 1632 identity for this type of device. In other words, the profile 1633 content server should not allow acme.example to assert an 1634 enrollment identity for a device manufactured by rival company 1635 widgets.example. 1636 4. The profile content server MUST verify that the device referred 1637 to by the device-id is not already enrolled. 1638 5. The profile content server MUST verify that the device referred 1639 to by the device-id is expected to enroll at the current time. 1640 Typically, an administrator would configure a time-window of 1641 hours or days during which a new device can enroll. 1643 If the profile content server successfully performs all these steps, 1644 it provides an initial device profile to the subscriber in the body 1645 of the HTTP response. This initial device profile MUST contain new 1646 credentials (for example, credentials for Digest authentication) that 1647 the subscriber can use for subsequent authentication. Integrity and 1648 confidentiality of the new profile is provided since the response is 1649 sent over a TLS channel. If one of the verification steps above 1650 fails, the profile content server sends a 403 Forbidden response. 1652 Entities other than the profile content server do not accept 1653 manufacturer device certificates to secure ordinary communications, 1654 such as SIP TLS or SIP S/MIME. 1656 11. Acknowledgements 1658 Many thanks to those who contributed and commented on the many 1659 iterations of this document. Detailed input was provided by Jonathan 1660 Rosenberg from Cisco, Henning Schulzrinne from Columbia University, 1661 Cullen Jennings from Cisco, Rohan Mahy from Plantronics, Rich Schaaf 1662 from Pingtel, Volker Hilt from Bell Labs, Adam Roach of Estacado 1663 Systems, Hisham Khartabil from Telio, Henry Sinnreich from MCI, 1664 Martin Dolly from AT&T Labs, John Elwell from Siemens, Elliot Eichen 1665 and Robert Liao from Verizon, Dale Worley from Pingtel, Francois 1666 Audet from Nortel, Roni Even from Polycom, Jason Fischl from 1667 Counterpath. 1669 12. Change History 1671 [[RFC Editor: Please remove this entire section upon publication as 1672 an RFC.]] 1674 12.1. Changes from draft-ietf-sipping-config-framework-08.txt 1676 The request URI for profile-type=localnet now SHOULD not have a 1677 user part to make routing easier. The From field SHOULD now 1678 contain the device id so that device tracking can still be done. 1679 Described the concept of profile-type as a filter and added 1680 normative text requiring 404 for profile types not provided. 1681 Moved "application" profile type to 1682 draft-ietf-sipping-xcap-config-01. The "application" value for 1683 the profile-type parameter will also be used as a requirement that 1684 XCAP be supported. 1685 Fixed text on certificate validation. 1686 Added new HTTP header: Event to IANA section and clean up the IANA 1687 section. 1688 Added diagram for service provider use case schenario. 1689 Added clarification for HTTP Event header. 1690 Added clarification of subscriber handling of NOTIFY with no body. 1692 12.2. Changes from draft-ietf-sipping-config-framework-07.txt 1693 Made XCAP informative reference. Removed "document" and "auid" 1694 event header parameters, and Usage of XCAP section to be put in 1695 separate supplementary draft. 1696 Fixed ABNF for network-user to be addr-spec only (not name-addr) 1697 and to be quoted as well. 1698 Synchronized with XCAP path terminology. Removed XCAP path 1699 definition as it is already defined in XCAP. 1700 User agent instance ID is now defined in output (not GRUU). 1701 Clarified the rational for the network-user parameter. 1702 Added text to suggest URIs for To and From fields. 1703 Clarified use of network-user parameter. 1704 Allow the use of the auid and document parameters per request by 1705 the OMA. 1707 12.3. Changes from draft-ietf-sipping-config-framework-06.txt 1709 Restructured the introduction and overview section to be more 1710 consistent with other Internet-Drafts. 1711 Added additional clarification for the Digest Authentication and 1712 Certificate based authentication cases in the security section. 1713 Added two use case scenarios with cross referencing to better 1714 illustrate how the framework works. Added better cross 1715 referencing in the overview section to help readers find where 1716 concepts and functionality is defined in the document. 1717 Clarified the section on the use of XCAP. Changed the Event 1718 parameter "App-Id" to "auid". Made "auid" mutually exclusive to 1719 "document". "auid" is now only used with XCAP. 1720 Local network subscription URI changed to @ 1721 (was anonymous@). Having a 1722 different request URI for each device allows the network 1723 management to track user agents and potentially manage bandwidth, 1724 port allocation, etc. 1725 Changed event package name from sip-profile to ua-profile per 1726 discussion on the list and last IETF meeting. 1727 Changed "local" profile type token to "local-network" per 1728 discussion on the list and last IETF meeting. 1729 Simplified "Vendor", "Model", "Version" event header parameters to 1730 allow only quoted string values (previously allowed token as 1731 well). 1732 Clarified use of the term cache. 1733 Added references for ABNF constructs. 1734 Numerous editorial changes. Thanks Dale! 1736 12.4. Changes from draft-ietf-sipping-config-framework-05.txt 1738 Made HTTP and HTTPS profile transport schemes mandatory in the 1739 profile delivery server. The subscribing device must implement 1740 HTTP or HTTPS as the profile transport scheme. 1742 Rewrote the security considerations section. 1743 Divided references into Normative and Informative. 1744 Minor edits throughout. 1746 12.5. Changes from draft-ietf-sipping-config-framework-04.txt 1748 Clarified usage of instance-id 1749 Specify which event header parameters are mandatory or optional 1750 and in which messages. 1751 Included complete list of event header parameters in parameter 1752 overview and IANA sections. 1753 Removed TFTP reference as protocol for profile transport. 1754 Added examples for discovery. 1755 Added ABNF for all event header parameters. 1756 Changed profile-name parameter back to profile-type. This was 1757 changed to profile-name in 02 when the parameter could contain 1758 either a token or a path. Now that the path is contained in the 1759 separate parameter: "document", profile-type make more sense as 1760 the parameter name. 1761 Fixed some statements that should have and should not have been 1762 normative. 1763 Added the ability for the user agent to request that the default 1764 user associated with the device be set/changed using the "network- 1765 user" parameter. 1766 A bunch of editorial nits and fixes. 1768 12.6. Changes from draft-ietf-sipping-config-framework-03.txt 1770 Incorporated changes to better support the requirements for the use 1771 of this event package with XCAP and SIMPLE so that we can have one 1772 package (i.e. simple-xcap-diff now defines a content type not a 1773 package). Added an additional profile type: "application". Added 1774 document and app-id Event header parameters in support of the 1775 application profile. Define a loose high level data model or 1776 relationship between the four profile types. Tried to edit and fix 1777 the confusing and ambiguous sections related to URI formation and 1778 discovery for the different profile types. Better describe the 1779 importance of uniqueness for the instance id which is used in the 1780 user part of the device URI. 1782 12.7. Changes from draft-ietf-sipping-config-framework-02.txt 1784 Added the concept of the local network as a source of profile data. 1785 There are now three separate logical sources for profile data: user, 1786 device and local network. Each of these requires a separate 1787 subscription to obtain. 1789 12.8. Changes from draft-ietf-sipping-config-framework-01.txt 1791 Changed the name of the profile-type event parameter to profile-name. 1792 Also allow the profile-name parameter to be either a token or an 1793 explicit URI. 1795 Allow content indirection to be optional. Clarified the use of the 1796 Accept header to indicate how the profile is to be delivered. 1798 Added some content to the Iana section. 1800 12.9. Changes from draft-ietf-sipping-config-framework-00.txt 1802 This version of the document was entirely restructured and re-written 1803 from the previous version as it had been micro edited too much. 1805 All of the aspects of defining the event package are now organized in 1806 one section and is believed to be complete and up to date with 1807 [RFC3265]. 1809 The URI used to subscribe to the event package is now either the user 1810 or device address or record. 1812 The user agent information (vendor, model, MAC and serial number) are 1813 now provided as event header parameters. 1815 Added a mechanism to force profile changes to be make effective by 1816 the user agent in a specified maximum period of time. 1818 Changed the name of the event package from sip-config to ua-profile 1820 Three high level security approaches are now specified. 1822 12.10. Changes from draft-petrie-sipping-config-framework-00.txt 1824 Changed name to reflect SIPPING work group item 1826 Synchronized with changes to SIP DHCP [RFC3361], SIP [RFC3261] and 1827 [RFC3263], SIP Events [RFC3265] and content indirection [I-D.ietf- 1828 sip-content-indirect-mech] 1830 Moved the device identity parameters from the From field parameters 1831 to User-Agent header parameters. 1833 Many thanks to Rich Schaaf of Pingtel, Cullen Jennings of Cisco and 1834 Adam Roach of Estacado Systems for the great comments and input. 1836 12.11. Changes from draft-petrie-sip-config-framework-01.txt 1838 Changed the name as this belongs in the SIPPING work group. 1840 Minor edits 1842 12.12. Changes from draft-petrie-sip-config-framework-00.txt 1844 Split the enrollment into a single SUBSCRIBE dialog for each profile. 1845 The 00 draft sent a single SUBSCRIBE listing all of the desired. 1846 These have been split so that each enrollment can be routed 1847 differently. As there is a concept of device specific and user 1848 specific profiles, these may also be managed on separate servers. 1849 For instance in a nomadic situation the device might get its profile 1850 data from a local server which knows the LAN specific profile data. 1851 At the same time the user specific profiles might come from the 1852 user's home environment profile delivery server. 1854 Removed the Config-Expires header as it is largely superfluous with 1855 the SUBSCRIBE Expires header. 1857 Eliminated some of the complexity in the discovery mechanism. 1859 Suggest caching information discovered about a profile delivery 1860 server to avoid an avalanche problem when a whole building full of 1861 devices powers up. 1863 Added the User-Profile From header field parameter so that the device 1864 can request a user specific profile for a user that is different from 1865 the device's default user. 1867 13. References 1869 13.1. Normative References 1871 [I-D.ietf-sip-content-indirect-mech] 1872 Burger, E., "A Mechanism for Content Indirection in 1873 Session Initiation Protocol (SIP) Messages", 1874 draft-ietf-sip-content-indirect-mech-05 (work in 1875 progress), October 2004. 1877 [I-D.ietf-sip-identity] 1878 Peterson, J. and C. Jennings, "Enhancements for 1879 Authenticated Identity Management in the Session 1880 Initiation Protocol (SIP)", draft-ietf-sip-identity-06 1881 (work in progress), October 2005. 1883 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1884 Requirement Levels", BCP 14, RFC 2119, March 1997. 1886 [RFC2132] Alexander, S. and R. Droms, "DHCP Options and BOOTP Vendor 1887 Extensions", RFC 2132, March 1997. 1889 [RFC2246] Dierks, T. and C. Allen, "The TLS Protocol Version 1.0", 1890 RFC 2246, January 1999. 1892 [RFC2616] Fielding, R., Gettys, J., Mogul, J., Frystyk, H., 1893 Masinter, L., Leach, P., and T. Berners-Lee, "Hypertext 1894 Transfer Protocol -- HTTP/1.1", RFC 2616, June 1999. 1896 [RFC2617] Franks, J., Hallam-Baker, P., Hostetler, J., Lawrence, S., 1897 Leach, P., Luotonen, A., and L. Stewart, "HTTP 1898 Authentication: Basic and Digest Access Authentication", 1899 RFC 2617, June 1999. 1901 [RFC2818] Rescorla, E., "HTTP Over TLS", RFC 2818, May 2000. 1903 [RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, 1904 A., Peterson, J., Sparks, R., Handley, M., and E. 1905 Schooler, "SIP: Session Initiation Protocol", RFC 3261, 1906 June 2002. 1908 [RFC3263] Rosenberg, J. and H. Schulzrinne, "Session Initiation 1909 Protocol (SIP): Locating SIP Servers", RFC 3263, 1910 June 2002. 1912 [RFC3265] Roach, A., "Session Initiation Protocol (SIP)-Specific 1913 Event Notification", RFC 3265, June 2002. 1915 [RFC3361] Schulzrinne, H., "Dynamic Host Configuration Protocol 1916 (DHCP-for-IPv4) Option for Session Initiation Protocol 1917 (SIP) Servers", RFC 3361, August 2002. 1919 [RFC4122] Leach, P., Mealling, M., and R. Salz, "A Universally 1920 Unique IDentifier (UUID) URN Namespace", RFC 4122, 1921 July 2005. 1923 13.2. Informative References 1925 [I-D.ietf-simple-xcap] 1926 Rosenberg, J., "The Extensible Markup Language (XML) 1927 Configuration Access Protocol (XCAP)", 1928 draft-ietf-simple-xcap-11 (work in progress), May 2006. 1930 [I-D.ietf-simple-xcap-diff] 1931 Rosenberg, J., "An Extensible Markup Language (XML) 1932 Document Format for Indicating A Change in XML 1933 Configuration Access Protocol (XCAP) Resources", 1934 draft-ietf-simple-xcap-diff-03 (work in progress), 1935 October 2006. 1937 [I-D.ietf-sip-outbound] 1938 Jennings, C. and R. Mahy, "Managing Client Initiated 1939 Connections in the Session Initiation Protocol (SIP)", 1940 draft-ietf-sip-outbound-04 (work in progress), June 2006. 1942 [I-D.ietf-sipping-ua-prof-framewk-reqs] 1943 Petrie, D. and C. Jennings, "Requirements for SIP User 1944 Agent Profile Delivery Framework", 1945 draft-ietf-sipping-ua-prof-framewk-reqs-00 (work in 1946 progress), March 2003. 1948 [I-D.petrie-sipping-profile-datasets] 1949 Petrie, D., "A Schema and Guidelines for Defining Session 1950 Initiation Protocol User Agent Profile Data Sets", 1951 draft-petrie-sipping-profile-datasets-03 (work in 1952 progress), October 2005. 1954 [I-D.sinnreich-sipdev-req] 1955 Sinnreich, H., "SIP Telephony Device Requirements and 1956 Configuration", draft-sinnreich-sipdev-req-08 (work in 1957 progress), October 2005. 1959 [RFC0822] Crocker, D., "Standard for the format of ARPA Internet 1960 text messages", STD 11, RFC 822, August 1982. 1962 [RFC0959] Postel, J. and J. Reynolds, "File Transfer Protocol", 1963 STD 9, RFC 959, October 1985. 1965 [RFC2131] Droms, R., "Dynamic Host Configuration Protocol", 1966 RFC 2131, March 1997. 1968 [RFC2141] Moats, R., "URN Syntax", RFC 2141, May 1997. 1970 [RFC2396] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform 1971 Resource Identifiers (URI): Generic Syntax", RFC 2396, 1972 August 1998. 1974 [RFC3377] Hodges, J. and R. Morgan, "Lightweight Directory Access 1975 Protocol (v3): Technical Specification", RFC 3377, 1976 September 2002. 1978 [W3C.REC-xml-names11-20040204] 1979 Hollander, D., Tobin, R., Bray, T., and A. Layman, 1980 "Namespaces in XML 1.1", World Wide Web Consortium 1981 FirstEdition REC-xml-names11-20040204, February 2004, 1982 . 1984 Author's Address 1986 Daniel Petrie 1987 SIPez LLC. 1988 34 Robbins Rd 1989 Arlington, MA 02476 1990 US 1992 Phone: "+1 617 273 4000 1993 Email: dan.ietf AT SIPez DOT com 1994 URI: http://www.SIPez.com/ 1996 Intellectual Property Statement 1998 The IETF takes no position regarding the validity or scope of any 1999 Intellectual Property Rights or other rights that might be claimed to 2000 pertain to the implementation or use of the technology described in 2001 this document or the extent to which any license under such rights 2002 might or might not be available; nor does it represent that it has 2003 made any independent effort to identify any such rights. Information 2004 on the procedures with respect to rights in RFC documents can be 2005 found in BCP 78 and BCP 79. 2007 Copies of IPR disclosures made to the IETF Secretariat and any 2008 assurances of licenses to be made available, or the result of an 2009 attempt made to obtain a general license or permission for the use of 2010 such proprietary rights by implementers or users of this 2011 specification can be obtained from the IETF on-line IPR repository at 2012 http://www.ietf.org/ipr. 2014 The IETF invites any interested party to bring to its attention any 2015 copyrights, patents or patent applications, or other proprietary 2016 rights that may cover technology that may be required to implement 2017 this standard. Please address the information to the IETF at 2018 ietf-ipr@ietf.org. 2020 Disclaimer of Validity 2022 This document and the information contained herein are provided on an 2023 "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS 2024 OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET 2025 ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, 2026 INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE 2027 INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED 2028 WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 2030 Copyright Statement 2032 Copyright (C) The Internet Society (2006). This document is subject 2033 to the rights, licenses and restrictions contained in BCP 78, and 2034 except as set forth therein, the authors retain all their rights. 2036 Acknowledgment 2038 Funding for the RFC Editor function is currently provided by the 2039 Internet Society.