idnits 2.17.1 draft-tschofenig-dime-diameter-qos-01.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 19. -- Found old boilerplate from RFC 3978, Section 5.5 on line 1893. -- Found old boilerplate from RFC 3979, Section 5, paragraph 1 on line 1904. -- Found old boilerplate from RFC 3979, Section 5, paragraph 2 on line 1911. -- Found old boilerplate from RFC 3979, Section 5, paragraph 3 on line 1917. ** 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 issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- ** The document seems to lack an IANA Considerations section. (See Section 2.2 of https://www.ietf.org/id-info/checklist for how to handle the case when there are no actions for IANA.) Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the RFC 3978 Section 5.4 Copyright Line does not match the current year == Line 1769 has weird spacing: '...-domain prici...' -- 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 20, 2006) is 6388 days in the past. Is this intentional? Checking references for intended status: Informational ---------------------------------------------------------------------------- == Missing Reference: 'TBD' is mentioned on line 1134, but not defined == Missing Reference: 'Flow-Id' is mentioned on line 1502, but not defined == Missing Reference: 'QoS-Filter-Rule' is mentioned on line 1503, but not defined == Missing Reference: 'SPI' is mentioned on line 1504, but not defined == Unused Reference: 'RFC2486' is defined on line 1808, but no explicit reference was found in the text == Unused Reference: 'RFC3313' is defined on line 1823, but no explicit reference was found in the text == Unused Reference: 'RFC3521' is defined on line 1831, but no explicit reference was found in the text == Unused Reference: 'RFC4027' is defined on line 1835, but no explicit reference was found in the text == Outdated reference: A later version (-24) exists of draft-ietf-nsis-qspec-12 ** Obsolete normative reference: RFC 2234 (Obsoleted by RFC 4234) ** Obsolete normative reference: RFC 3588 (Obsoleted by RFC 6733) ** Obsolete normative reference: RFC 4005 (Obsoleted by RFC 7155) ** Obsolete normative reference: RFC 4006 (Obsoleted by RFC 8506) == Outdated reference: A later version (-20) exists of draft-ietf-nsis-ntlp-11 == Outdated reference: A later version (-18) exists of draft-ietf-nsis-qos-nslp-11 -- Obsolete informational reference (is this intentional?): RFC 2327 (Obsoleted by RFC 4566) -- Obsolete informational reference (is this intentional?): RFC 2486 (Obsoleted by RFC 4282) Summary: 8 errors (**), 0 flaws (~~), 13 warnings (==), 9 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Diameter Maintanence and F. Alfano 3 Extensions (DIME) P. McCann 4 Internet-Draft Lucent Technologies 5 Intended status: Informational H. Tschofenig 6 Expires: April 23, 2007 Siemens 7 T. Tsenov 8 T. Tsou 9 October 20, 2006 11 Diameter Quality of Service Application 12 draft-tschofenig-dime-diameter-qos-01.txt 14 Status of this Memo 16 By submitting this Internet-Draft, each author represents that any 17 applicable patent or other IPR claims of which he or she is aware 18 have been or will be disclosed, and any of which he or she becomes 19 aware will be disclosed, in accordance with Section 6 of BCP 79. 21 Internet-Drafts are working documents of the Internet Engineering 22 Task Force (IETF), its areas, and its working groups. Note that 23 other groups may also distribute working documents as Internet- 24 Drafts. 26 Internet-Drafts are draft documents valid for a maximum of six months 27 and may be updated, replaced, or obsoleted by other documents at any 28 time. It is inappropriate to use Internet-Drafts as reference 29 material or to cite them other than as "work in progress." 31 The list of current Internet-Drafts can be accessed at 32 http://www.ietf.org/ietf/1id-abstracts.txt. 34 The list of Internet-Draft Shadow Directories can be accessed at 35 http://www.ietf.org/shadow.html. 37 This Internet-Draft will expire on April 23, 2007. 39 Copyright Notice 41 Copyright (C) The Internet Society (2006). 43 Abstract 45 This document describes a Diameter application that performs 46 Authentication, Authorization, and Accounting for Quality of Service 47 (QoS) reservations. This protocol is used by elements along the path 48 of a given application flow to authenticate a reservation request, 49 ensure that the reservation is authorized, and to account for 50 resources consumed during the lifetime of the application flow. 51 Clients that implement the Diameter QoS application contact an 52 authorizing entity/application server that is located somewhere in 53 the network, allowing for a wide variety of flexible deployment 54 models. 56 Table of Contents 58 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 59 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 60 3. Framework . . . . . . . . . . . . . . . . . . . . . . . . . . 6 61 3.1. Network element functional model . . . . . . . . . . . . . 7 62 3.2. Authorization models . . . . . . . . . . . . . . . . . . . 9 63 3.3. QoS authorization considerations . . . . . . . . . . . . . 13 64 4. Diameter QoS Authorization session establishment and 65 management . . . . . . . . . . . . . . . . . . . . . . . . . . 18 66 4.1. Parties involved . . . . . . . . . . . . . . . . . . . . . 18 67 4.2. Initial QoS authorization (Diameter QoS authorization 68 session establishment) . . . . . . . . . . . . . . . . . . 18 69 4.3. QoS authorization session re-authorization . . . . . . . . 22 70 4.3.1. Client-side initiated Re-Authorization . . . . . . . . 22 71 4.3.2. Server-side initiated Re-Authorization . . . . . . . . 24 72 4.4. Server-side initiated QoS parameter provisioning . . . . . 24 73 4.5. Session Termination . . . . . . . . . . . . . . . . . . . 25 74 4.5.1. Client-side initiated session termination . . . . . . 25 75 4.5.2. Server-side initiated session termination . . . . . . 26 76 5. Accounting . . . . . . . . . . . . . . . . . . . . . . . . . . 28 77 6. Diameter QoS authorization application Messages . . . . . . . 30 78 6.1. QoS-Authorization Request (QAR) . . . . . . . . . . . . . 31 79 6.2. QoS-Authorization Answer (QAA) . . . . . . . . . . . . . . 31 80 6.3. QoS-Install Request (QIR) . . . . . . . . . . . . . . . . 32 81 6.4. QoS-Install Answer (QIA) . . . . . . . . . . . . . . . . . 33 82 6.5. Accounting Request (ACR) . . . . . . . . . . . . . . . . . 33 83 6.6. Accounting Answer (ACA) . . . . . . . . . . . . . . . . . 34 84 7. Diameter QoS Authorization Application AVPs . . . . . . . . . 35 85 7.1. Diameter Base Protocol AVPs . . . . . . . . . . . . . . . 35 86 7.2. Credit Control application AVPs . . . . . . . . . . . . . 35 87 7.3. Accounting AVPs . . . . . . . . . . . . . . . . . . . . . 36 88 7.4. Diameter QoS Application Defined AVPs . . . . . . . . . . 37 89 8. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 90 9. Security Considerations . . . . . . . . . . . . . . . . . . . 44 91 10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 45 92 11. Open Issues . . . . . . . . . . . . . . . . . . . . . . . . . 46 93 12. References . . . . . . . . . . . . . . . . . . . . . . . . . . 47 94 12.1. Normative References . . . . . . . . . . . . . . . . . . . 47 95 12.2. Informative References . . . . . . . . . . . . . . . . . . 47 96 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 50 97 Intellectual Property and Copyright Statements . . . . . . . . . . 51 99 1. Introduction 101 To meet the Quality of Service needs of applications such as Voice- 102 over-IP in a heavily loaded network, packets belonging to real-time 103 application flows must be identified and segregated from other 104 traffic to ensure that bandwidth, delay, and loss rate requirements 105 are met. In addition, new flows should not be added to the network 106 when it is at or near capacity, which would result in degradation of 107 quality for all flows carried by the network. 109 In some cases, these goals can be achieved with mechanisms such as 110 differentiated services and/or end-to-end congestion and admission 111 control. However, when bandwidth is scarce and must be carefully 112 managed, such as in cellular networks, or when applications and 113 transport protocols lack the capability to perform end-to-end 114 congestion control, explicit reservation techniques are required. In 115 these cases, the endpoints will send reservation requests to edge 116 and/or interior nodes along the communication path. In addition to 117 verifying whether resources are available, the recipient of a 118 reservation request must also authenticate and authorize the request, 119 especially in an environment where the endpoints are not trusted. In 120 addition, these nodes will generate accounting information about the 121 resources used and attribute usage to the requesting endpoints. This 122 will enable the owner of the network element to generate usage- 123 sensitive billing records and to understand how to allocate new 124 network capacity. 126 A variety of protocols could be used to make a QoS request, including 127 RSVP [RFC2210], NSIS [I-D.ietf-nsis-qos-nslp], link-specific 128 signaling or even SIP/SDP [RFC2327]. This document aims to be 129 agnostic to the QoS signaling protocol used and to the QoS model to 130 which the signaling is directed. 132 2. Terminology 134 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 135 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 136 document are to be interpreted as described in RFC 2119 [RFC2119]. 138 The following terms are used in this document: 140 Application Server 142 An application server is a network entity that exchanges signaling 143 messages with an application endpoint. It may be a source of 144 authorization for QoS-enhanced application flows. For example, a 145 SIP server is one kind of application server. 147 Application Endpoint 149 An application endpoint is an entity in an end user device that 150 exchanges signaling messages with application servers or directly 151 with other application endpoints. Based on the result of this 152 signaling, the endpoint will make a request for QoS from the 153 network. For example, a SIP User Agent is one kind of application 154 endpoint. 156 Authorizing Entity 158 The authorizing entity is that entity responsible for authorizing 159 QoS requests for a particular application flow or aggregate. This 160 may be a Diameter server (with a subscriber database) or an 161 application server acting as a Diameter server. 163 AAA Cloud 165 An infrastructure of AAA entities (clients, proxies, servers) 166 based on a AAA protocol, which provides trusted secure connections 167 between them. It offers authentication, authorization and 168 accounting services to applications in flexible local and roaming 169 scenarios. Diameter [RFC3588] and RADIUS [RFC2865] and both 170 widely deployed AAA protocols. 172 Network Element (NE) 174 QoS aware router that acts as Diameter client that implements the 175 Diameter QoS application in the context of this document. For 176 almost all scenarios this entity triggers the protocol interaction 177 described in this document. This entity corresponds to the Policy 178 Enforcement Point (PEP) (see [RFC2753]) from a functionality point 179 of view. 181 3. Framework 183 The Diameter QoS application runs between a network element receiving 184 QoS reservation requests (acting as a AAA client) and the resource 185 authorizing entity (acting as a AAA server). A high-level picture of 186 the resulting architecture is shown in Figure 1. 188 +-----------------+ 189 | Authorizing | 190 | Entity | 191 |(Diameter Server)| 192 +-------+---------+ 193 | 194 | 195 /\-----+-----/\ 196 //// \\\\ 197 || AAA Cloud || 198 | (Diameter application) | 199 || || 200 \\\\ //// 201 \-------+-----/ 202 | 203 +---+--+ +-----+----+ +---+--+ 204 | | | NE | | | Application 205 + NE +===+(Diameter +===+ NE +=============>> 206 | | | Client) | | | Flow 207 +------+ +----------+ +------+ 209 Figure 1: An Architecture supporting QoS-AAA 211 Figure 1 depicts network elements through which application flows 212 need to pass, a cloud of AAA servers, and an authorizing entity. 213 Note that there may be more than one router that needs to interact 214 with the AAA cloud along the path of a given application flow, 215 although the figure only depicts one for clarity. QoS aware network 216 elements will request authorization from the AAA cloud based on an 217 incoming QoS reservation request. The AAA entities will route the 218 request to a designated AAA authorizing entity, for example in the 219 home domain. The home authorizing entity will return the result of 220 the authorization decision. 222 In more complex deployment models, the authorization will be based on 223 dynamic application state, so that the request must be authenticated 224 and authorized based on information from one or more application 225 servers. If defined properly, the interface between the routers and 226 AAA cloud would be identical in both cases. Routers are therefore 227 insulated from the details of particular applications and need not 228 know that application servers are involved at all. Also, the AAA 229 cloud would naturally encompass business relationships such as those 230 between network operators and third-party application providers, 231 enabling flexible intra- or inter-domain authorization, accounting, 232 and settlement. 234 3.1. Network element functional model 236 Figure 2 depicts a logical operational model of resource management 237 in a router. 239 +-----------------------------------------------------+ 240 | DIAMETER Client | 241 | Functionality | 242 | +---------------++---------------++---------------+ | 243 | | User || Authorization || Accounting | | 244 | | Authentication|| of QoS || for QoS | | 245 | +---------------+| Requests || Traffic | | 246 | +---------------++---------------+ | 247 +-----------------------------------------------------+ 248 ^ 249 v 250 +--------------+ +----------+ 251 |QoS Signaling | | Resource | 252 |Msg Processing|<<<<<>>>>>>>|Management| 253 +--------------+ +----------+ 254 . ^ | * ^ 255 | v . * ^ 256 +-------------+ * ^ 257 |Signaling msg| * ^ 258 | Processing | * V 259 +-------------+ * V 260 | | * V 261 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 262 . . * V 263 | | * ............................. 264 . . * . Traffic Control . 265 | | * . +---------+. 266 . . * . |Admission|. 267 | | * . | Control |. 268 +----------+ +------------+ . +---------+. 269 <-.-| Input | | Outgoing |-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-> 270 | Packet | | Interface | .+----------+ +---------+. 271 ===>|Processing|====| Selection |===.| Packet |====| Packet |.=> 272 | | |(Forwarding)| .|Classifier| Scheduler|. 273 +----------+ +------------+ .+----------+ +---------+. 274 ............................. 275 <.-.-> = signaling flow 276 =====> = data flow (sender --> receiver) 277 <<<>>> = control and configuration operations 278 ****** = routing table manipulation 280 Figure 2: Network element functional model 282 Processing of incoming QoS reservation requests includes three 283 actions: admission control, authorization and resource reservation. 285 The admission control function provides information for available 286 resources and determines whether there are enough resources to 287 fulfill the request. Authorization is performed by the Diameter 288 client function which involves contacting an authorization entity 289 through the AAA cloud shown in Section 3. If both checks are 290 successful, the authorized QoS parameters are set in the packet 291 classifier and the packet scheduler. Note that the parameters passed 292 to the Traffic Control function may be different from requested QoS 293 (depending on the authorization decision). Once the requested 294 resource is granted, the Resource Management function provides 295 accounting information to the Authorizing entity using the Diameter 296 client function. 298 3.2. Authorization models 300 Three fundamental models for authorizing QoS reservations exist: one 301 two-party and two three party models. See 302 [I-D.tschofenig-nsis-aaa-issues] and in 303 [I-D.tschofenig-nsis-qos-authz-issues] for a more detailed discussion 304 of authorization models and the impact for QoS reservations. The 305 notation adopted here is in respect to the entity that performs the 306 QoS authorization. The authentication of the QoS requesting entity 307 might be done at the network element as part of the QoS signaling 308 protocol, or by an off-path protocol run (on the application layer or 309 for network access authentication) or the authorizing entity might be 310 contacted with request for authentication and authorization of the 311 QoS requesting entity. From the Diameter QoS application's point of 312 view these models differ in type of information that need to be 313 carried. Here we focus on the 'Three party model' (Figure 3) and the 314 Token-based three party model' (Figure 4). With the 'Two party 315 model' the QoS resource requesting entity is authenticated by the 316 Network Element and the authorization decision is made either locally 317 at the Network Element itself or offloaded to a trusted entity (most 318 likely within the same administrative domain). In the former case no 319 Diameter QoS protocol interaction is required. 321 +--------------+ 322 | Entity | 323 | authorizing | <......+ 324 | resource | . 325 | request | . 326 +------------+-+ . 327 --^----------|-- . . 328 ///// | | \\\\\ . 329 // | | \\ . 330 | QoS | QoS AAA | QoS |. 331 | authz| protocol |authz |. 332 | req.| | res. |. 333 \\ | | // . 334 \\\\\ | | ///// . 335 QoS --|----------v-- . . 336 +-------------+ request +-+------------+ . 337 | Entity |----------------->| NE | . 338 | requesting | | performing | . 339 | resource |granted / rejected| QoS | <.....+ 340 | |<-----------------| reservation | financial 341 +-------------+ +--------------+ settlement 343 Figure 3: Three Party Model 345 With the 'Three party model' a QoS reservation request that arrives 346 at the Network Element is forwarded to the Authorizing Entity (e.g., 347 in the user's home network), where the authorization decision is 348 made. A business relationship, such as a roaming agreement, between 349 the visited network and the home network ensures that the visited 350 network is compensated for the resources consumed by the user via the 351 home network. 353 financial settlement 354 ...........................+ 355 Authorization V ------- . 356 Token Request +--------------+ / QoS AAA \ . 357 +-------------->| | / protocol \ . 358 | | Authorizing +--------------+ \ . 359 | | Entity | | | | . 360 | +------+ |<--+----+ | | . 361 | | +--------------+ |QoS | |QoS |. 362 | | |authz| |authz|. 363 | |Authorization |req.+| |res. |. 364 | |Token |Token| | |. 365 | | | | | . | . 366 | | \ | | . / . 367 | | \ | | / . 368 | | QoS request |-----V . . 369 +-------------+ + Authz. Token +--------+-----+ . 370 | Entity |----------------->| NE | . 371 | requesting | | performing | . 372 | resource |granted / rejected| QoS | <....+ 373 | |<-----------------| reservation | 374 +-------------+ +--------------+ 376 Figure 4: Token-based Three Party Model 378 The 'Token-based Three Party model' is applicable to environments 379 where a previous protocol interaction is used to request 380 authorization tokens to assist the authorization process at the 381 Network Element or the Authorizing Entity. 383 The QoS resource requesting entity may be involved in an application 384 layer protocol interaction, for example using SIP, with the 385 Authorizing Entity. As part of this interaction, authentication and 386 authorization at the application layer might take place. As a result 387 of a successful authorization decision, which might involve the 388 user's home AAA server, an authorization token is generated by the 389 Authorizing Entity (e.g., the SIP proxy and an entity trusted by the 390 SIP proxy) and returned to the end host for inclusion into the QoS 391 signaling protocol. The authorization token will be used by a 392 Network Element that receives the QoS signaling message to authorize 393 the QoS request. Alternatively, the Diameter QoS application will be 394 used to forward the authorization token to the user's home network. 395 The authorization token allows the authorization decision performed 396 at the application layer protocol run to be associated with a 397 corresponding QoS signaling session. Note that the authorization 398 token might either refer to established state concerning the 399 authorization decision or the token might itself carry the authorized 400 parameters (protected by a digital signature or a keyed message 401 digest to prevent tampering). In the latter case the authorization 402 token may contain several pieces of information pertaining to the 403 authorized application session, but at minimum it should contain: 404 o An identifier of the Authorizing Entity (for example, of an 405 application server) that issued the authorization token, 406 o An identifier referring to a specific application protocol session 407 for which the token was issued and 408 o A keyed message digest or digital signature protecting the content 409 of the authorization token. 411 A possible structure for the authorization token and the policy 412 element carrying it are proposed in context of RSVP [RFC3520], with 413 the OSP [ETSI-OSP] or as outlined in [I-D.ietf-sipping-trait-authz] 414 and [I-D.tschofenig-sip-saml]. 416 In the scenario mentioned above, where the QoS resource requesting 417 entity is involved in an application layer protocol interaction with 418 the Authorizing entity, it may be worthwhile to consider a token less 419 binding mechanism also. The application layer protocol interaction 420 may have indicated the transport port numbers at the QoS resource 421 requesting entity where it might receive media streams, for example 422 in SIP/SDP signalling these port numbers are advertised. The QoS 423 resource requesting entity may also use these port numbers in some IP 424 filter indications to the NE performing QoS reservation so that it 425 may properly tunnel the inbound packets. The NE performing QoS 426 reservation will forward the QoS resource requesting entity's IP 427 address and the IP filter indications to the Authorizing entity in 428 the QoS authz. request. The Authorizing entity will use the QoS 429 resource requesting entity's IP address and the port numbers in the 430 IP filter indication, which will match the port numbers advertised in 431 the earlier application layer protocol interaction, to identify the 432 right piece of policy information to be sent to the NE performing the 433 QoS reservation in the QoS authz. response. 435 A Three party model based on "push" - where the Authorizing entity, 436 subsequent to a successful application layer authorization, will send 437 the policy information unsolicited to the NE performing QoS 438 reservation is shown below. 440 financial settlement 441 ...........................+ 442 Application Layer V ------- . 443 Protocol +--------------+ / QoS AAA \ . 444 +-------------->| | / protocol \ . 445 | | Authorizing +--------------+ \ . 446 | | Entity | | | | . 447 | + |<--+----+ | | . 448 | +--------------+ |QoS | |QoS |. 449 | install| |install 450 | |rsp. | |req. |. 451 | | | | |. 452 | | | | . | . 453 | \ | | . / . 454 | \ | | / . 455 V |-----V . . 456 +-------------+ +--------+-----+ . 457 | Entity | | NE | . 458 | requesting | | performing | . 459 | resource |QoS rsrc granted | QoS | <....+ 460 | |<-----------------| reservation | 461 +-------------+ +--------------+ 463 Figure 5: Three Party Push Model 465 In the three party QoS model where the QoS resource requesting entity 466 is involved in an application layer protocol interaction with the 467 Authorizing entity, the Authorizing entity may be considered as two 468 separate functional entities - an Application function (AF)and a 469 Policy Decision function (PDF). The AF and PDF interact using the 470 QoS AAA protocol. The AF will pass dynamic QoS-related application 471 information with the PDF. The PDF will choose the right piece of 472 policy information to be applied at the Policy Enforcement Point 473 (PEP) in the NE performing QoS reservation. 475 The policy information may be pushed to the PEP or may be requested/ 476 pulled by the NE performing QoS reservation. The first message of 477 the QoS AAA session between the AF and the PDF may include an 478 indication on whether to use the push or the pull mode. 480 3.3. QoS authorization considerations 482 A QoS authorization application must meet a number of requirements 483 applicable to a diverse set of networking environments and services. 484 It should be compliant with different deployment scenarios with 485 specific QoS signaling models and security issues. Satisfying the 486 requirements listed below while interworking with QoS signaling 487 protocols, a Diameter QoS application should accommodate the 488 capabilities of the QoS signaling protocols rather than introducing 489 functional requirements on them. A list of requirements for a QoS 490 authorization application is provided here: 491 Inter-domain support 493 In particular, users may roam outside their home network, leading 494 to a situation where the network element and authorizing entity 495 are in different administrative domains. 497 Identity-based Routing 499 The QoS AAA protocol MUST route AAA requests to the Authorizing 500 Entity, based on the provided identity of the QoS requesting 501 entity or the identity of the Authorizing entity encoded in the 502 provided authorization token. 504 Flexible Authentication Support 506 The QoS AAA protocol MUST support a variety of different 507 authentication protocols for verification of authentication 508 information present in QoS signaling messages. The support for 509 these protocols MAY be provided indirectly by tying the signaling 510 communication for QoS to a previous authentication protocol 511 exchange (e.g., using network access authentication). 513 Making an Authorization Decision 515 The QoS AAA protocol MUST exchange sufficient information between 516 the authorizing entity and the enforcing entity (and vice versa) 517 to compute an authorization decision and to execute this decision. 519 Triggering an Authorization Process 521 The QoS AAA protocol MUST allow periodic and event triggered 522 execution of the authorization process, originated at the 523 enforcing entity or even at the authorizing entity. 525 Associating QoS Reservations and Application State 527 The QoS AAA protocol MUST carry information sufficient for an 528 application server to identify the appropriate application session 529 and associate it with a particular QoS reservation. 531 Dynamic Authorization 533 It MUST be possible for the QoS AAA protocol to push updates 534 towards the network element(s) from authorizing entities. 536 Bearer Gating 538 The QoS AAA protocol MUST allow the authorizing entity to gate 539 (i.e., enable/disable) authorized application flows based on e.g., 540 application state transitions. 542 Accounting Records 544 The QoS AAA protocol MUST define QoS accounting records containing 545 duration, volume (byte count) usage information and description of 546 the QoS attributes (e.g., bandwidth, delay, loss rate) that were 547 supported for the flow. 549 Sending Accounting Records 551 The network element SHOULD send accounting records for a 552 particular QoS reservation state to the authorizing entity, which 553 plays the role of an accounting entity. 555 Failure Notification 557 The QoS AAA protocol MUST allow the network element to report 558 failures(such as loss of connectivity due to movement of a mobile 559 node or other reasons for packet loss) to the authorizing entity. 561 Accounting Correlation 563 The QoS AAA protocol MUST support the exchange of sufficient 564 information to allow for correlation between accounting records 565 generated by the network elements and accounting records generated 566 by an application server. 568 Interaction with other AAA Applications 569 Interaction with other AAA applications such as Diameter Network 570 Access (NASREQ) application [RFC4005] is required for exchange of 571 authorization, authentication and accounting information. 573 In deployment scenarios, where authentication of the QoS reservation 574 requesting entity (e.g., the user) is done by means outside the 575 Diameter QoS application protocol interaction the Authorizing Entity 576 is contacted only with a request for QoS authorization. 577 Authentication might have taken place already via the interaction 578 with the Diameter NASREQ application or as part of the QoS signaling 579 protocol (e.g., Transport Layer Security (TLS) handshake in General 580 Internet Signaling Transport (GIST) [I-D.ietf-nsis-ntlp]). 582 Authentication of the QoS reservation requesting entity to the 583 Authorizing Entity is necessary if a particular Diameter QoS 584 application protocol run cannot be related (of if there is no 585 intention to relate it) to a prior authentication. In this case the 586 Authorizing Entity MUST authenticate the QoS reservation requesting 587 entity in order to authorize the QoS request as part of the Diameter 588 QoS protocol interaction. 590 The document refers to three types of sessions that need to be 591 properly correlated. 592 QoS signaling session 594 The time period during which a QoS signaling protocol establishes, 595 maintains and deletes a QoS reservation state at the QoS network 596 element is referred as QoS signaling session. Different QoS 597 signaling protocols use different ways to identify QoS signaling 598 sessions. The same applies to different usage environments. 599 Currently, this document supports three types of QoS session 600 identifiers, namely a signaling session id (e.g., the Session 601 Identifier used by the NSIS protocol suite), a flow id (e.g., 602 identifier assigned by an application to a certain flow as used in 603 the 3GPP) and a flow description based on the IP parameters of the 604 flow's end points). The details can be found in Section 7.4. 606 Diameter authorization session 608 The time period, for which a Diameter server authorizes a 609 requested service (i.e., QoS resource reservation). It is 610 identified by a Session-Id included in all Diameter messages used 611 for management of the authorized service (initial authorization, 612 re-authorization, termination)[RFC3588]. 614 Application layer session 616 The application layer session identifies the duration of an 617 application layer service which requires provision of certain QoS. 618 An application layer session identifier is provided by the QoS 619 requesting entity in the QoS signaling messages, for example as 620 part of the authorization token. In general, the application 621 session identifier is opaque to the QoS aware network elements. 622 It is included in the authorization request message sent to the 623 Authorizing entity and helps it to correlate the QoS authorization 624 request to the application session state information. (see 625 Figure 4). 627 Correlation of these sessions is done at each of the three involved 628 entities: The QoS requesting entity correlates the application with 629 the QoS signaling sessions. The QoS network element correlates the 630 QoS signaling session with the Diameter authorization sessions. The 631 Authorizing entity SHOULD bind the information about the three 632 sessions together. Note that in certain scenarios not all of the 633 sessions are present. For example, the application session might not 634 be visible to QoS signaling protocol directly if there is no binding 635 between the application session and the QoS requesting entity using 636 the QoS signaling protocol. 638 4. Diameter QoS Authorization session establishment and management 640 4.1. Parties involved 642 Authorization models supported by this application include three 643 parties: 644 o Resource requesting entity 645 o Network Elements (Diameter QoS clients) 646 o Authorizing Entity (Diameter QoS server) 647 Note that the QoS resource requesting entity is only indirectly 648 involved in the message exchange. This entity provides the trigger 649 to initiate the Diameter QoS protocol interaction by transmitting QoS 650 signaling messages. The Diameter QoS application is only executed 651 between the Network Element (i.e., Diameter QoS client) and the 652 Authorizing Entity (i.e., Diameter QoS server). 654 The QoS resource requesting entity may communicate with the 655 Authorizing Entity using application layer signaling for negotiation 656 of service parameters. As part of this application layer protocol 657 interaction, for example using SIP, authentication and authorization 658 might take place (see Figure 4). This message exchange is, however, 659 outside the scope of this document. The protocol communication 660 between the the QoS resource requesting entity and the QoS Network 661 Element might be accomplished using the NSIS protocol suite, RSVP or 662 a link layer signaling protocol. A description of these protocols is 663 also outside the scope of this document and a tight coupling with 664 these protocols is not desirable since this applications aims to be 665 generic. 667 4.2. Initial QoS authorization (Diameter QoS authorization session 668 establishment) 670 Figure 7 shows the protocol interaction between a resource requesting 671 entity, a Network Element and the Authorizing Entity. 673 A request for a QoS reservation received by a Network Element 674 initiates a Diameter QoS authorization session. The Network Element 675 generates a QoS-Authorization-Request (QAR) message in which it maps 676 required objects from the QoS signaling message to Diameter payload 677 objects - Attribute Value Pairs (AVPs, [RFC3588]). 679 +----------------------------------+-------------------------------+ 680 | QoS authorization data | Diameter QoS AVPs (Section 7) | 681 +----------------------------------+-------------------------------+ 682 | Authorizing entity ID (e.g., | Destination-Host | 683 |taken from authorization token or | Destination-Realm | 684 |from Network Access ID(NAI), | | 685 |[RFC2486] of the QoS requesting | | 686 |entity) | | 687 +----------------------------------+-------------------------------+ 688 | Application session Id (authori- | QoS-Authorization-Data | 689 | zation token) / credentials of | User-Name | 690 | the QoS requesting entity | | 691 +----------------------------------+-------------------------------+ 692 | QoS parameters | QSPEC | 693 +----------------------------------+-------------------------------+ 694 | Signaling session Id / Flow(s) Id| Signaling-session | 695 | | Flows | 696 +----------------------------------+-------------------------------+ 698 The Authorizing Entity's identity, information about the application 699 session and/or identity and credentials of the QoS resource 700 requesting entity, requested QoS parameters, signaling session 701 identifier and/or QoS enabled data flows identifiers MAY be 702 encapsulated into respective Diameter AVPs and included into the 703 Diameter message sent to the Authorizing Entity. The QAR is sent to 704 a Diameter server that can either be the home server of the QoS 705 requesting entity or an application server. 707 Authorization processing starts at the Diameter QoS server when it 708 receives the QAR authorization processing starts. Based on the 709 information in the QoS-Authentication-Data, User-Name-ID and QoS- 710 Authorized-Resources AVPs the server determines the authorized QoS 711 resources and flow state (enabled/disabled) from locally available 712 information (e.g., policy information that may be previously 713 established as part of an application layer signaling exchange, or 714 the user's subscription profile). The authorization decision is then 715 reflected in the response returned to the Diameter client with the 716 QoS-Authorization-Answer message (QAA). 718 Authorizing 719 End-Host Network Element Entity 720 requesting QoS ( Diameter ( Diameter 721 QoS Client) QoS Server) 722 | | | 723 +---QoS-Reserve---->| | 724 | +- - - - - QAR - - - - - >| 725 | |(QoS-Resources,Cost, | 726 | | QoS-Auth-Data,User-ID)| 727 | | +--------+--------------+ 728 | | | Authorize request | 729 | | | Keep session data | 730 | | |/Authz-time,Session-Id/| 731 | | +--------+--------------+ 732 | |< - - - - QAA - - - - - -+ 733 | |(Result-Code,CC-Time,Cost| 734 | |QoS-Resources,Authz-time)| 735 | +-------+---------+ 736 | |Install QoS state| 737 | | + | 738 | | Authz. session | 739 | | /Authz-time, | QoS Responder 740 | | CC-Time,Cost/ | Node 741 | +-------+---------+ | 742 | +----------QoS-Reserve---....--->| 743 | | | 744 | |<---------QoS-Response--....----| 745 |<--QoS-Response----+ | 746 | | | 747 |=====================Data Flow==============....===>| 748 | | 749 | +- - - - - ACR - - - - - >| 750 | |(START,QoS-Resources,Cost| 751 | |CC-Time,Acc-Multisess-id)| 752 | | +--------+--------------+ 753 | | | Report for successful | 754 | | | QoS reservation | 755 | | |Update of reserved QoS | 756 | | | resources | 757 | | +--------+--------------+ 758 | |< - - - - ACA - - - - - -+ 759 | | | 761 Figure 7: Initial QoS request authorization 763 The Authorizing Entity keeps authorization session state and SHOULD 764 save additional information for management of the session (e.g., Acc- 765 Multi-Session-Id, Signaling-Session-Id, authentication data) as part 766 of the session state information. A Signaling-session-Id (if 767 present) SHOULD be used together with the generated Acc-Multi- 768 Session-Id AVP (see Section 7.3) for binding the authorization and 769 the accounting session information in case of end host mobility 770 (i.e., to correlate the Diameter sessions that are initiated for the 771 same signaling session from different QoS NE). 773 The final result of the authorization request is provided in the 774 Result-Code AVP of the QAA message sent by the Authorizing Entity. 775 In case of successful authorization (i.e., Result-Code = 776 DIAMETER_LIMITED_SUCCESS, (see Section 7.1)), information about the 777 authorized QoS resources and the status of the authorized flow 778 (enabled/disabled) is provided in the QoS-Authorization-Resources AVP 779 of the QAA message. The QoS information provided via the QAA is 780 installed by the QoS Traffic Control function of the Network Element 781 (see Figure 2). The value DIAMETER_LIMITED_SUCCESS indicates that 782 the Authorizing entity expects confirmation via an accounting message 783 for successful QoS resource reservation and for final reserved QoS 784 resources (see bellow). 786 One important piece of information returned from the Authorizing 787 Entity is the authorization lifetime (carried inside the QAA). The 788 authorization lifetime allows the Network Element to determine how 789 long the authorization decision is valid for this particular QoS 790 reservation. A number of factors may influence the authorized 791 session duration, such as the user's subscription plan or currently 792 available credits at the user's account (see Section 5). The 793 authorization duration is time-based as specified in [RFC3588]. For 794 an extension of the authorization period, a new QoS-Authorization- 795 Request/Answer message exchange SHOULD be initiated. Further aspects 796 of QoS authorization session maintenance is discussed in Section 4.3, 797 Section 4.5 and Section 5. 799 The indication of a successful QoS reservation and activation of the 800 data flow, is provided by the transmission of an Accounting Request 801 (ACR) message, which reports the parameters of the established QoS 802 state: reserved resources, duration of the reservation, 803 identification of the QoS enabled flow/QoS signaling session and 804 accounting parameters. The Diameter QoS server acknowledges the 805 reserved QoS resources with the Accounting Answer (ACA) message where 806 the Result-Code is set to 'DIAMETER_SUCCESS'. Note that the reserved 807 QoS resources reported in the ACR message MAY be different than those 808 initially authorized with QAA message, due to the QoS signaling 809 specific behavior (e.g., receiver-initiated reservations with One- 810 Path-With-Advertisements) specific process of QoS negotiation along 811 the data path. 813 4.3. QoS authorization session re-authorization 815 Client and server-side initiated re-authorizations are considered in 816 the design of the Diameter QoS application. Whether the re- 817 authorization events are transparent for the resource requesting 818 entity or result in specific actions in the QoS signaling protocol is 819 outside the scope of the Diameter QoS application. It is directly 820 dependent on the capabilities of the QoS signaling protocol. 822 In addition, there are number of options for policy rules according 823 to which the NE (AAA client) contacts the Authorizing Entity for re- 824 authorization. These rules depend on the semantics and contents of 825 the QAA message sent by the Authorizing Entity: 826 a. The QAA message contains the authorized parameters of the flow 827 and its QoS and sets their limits (presumably upper). With these 828 parameters the Authorizing Entity specifies the services that the 829 NE can provide and will be financially compensated for. 830 Therefore, any change or request for change of the parameters of 831 the flow and its QoS that do not conform to the authorized limits 832 requires contacting the Authorizing Entity for authorization. 833 b. The QAA message contains authorized parameters of the flow and 834 its QoS. The rules that determine whether parameters' changes 835 require re-authorization are agreed out of band, based on a 836 Service Level Agreement (SLA) between the domains of the NE and 837 the Authorizing Entity. 838 c. The QAA message contains the authorized parameters of the flow 839 and its QoS. Any change or request for change of these 840 parameters requires contacting the Authorizing entity for re- 841 authorization. 842 d. In addition to the authorized parameters of the flow and its QoS, 843 the QAA message contains policy rules that determine the NEs 844 actions in case of change or request for change in authorized 845 parameters. 847 Provided options are not exhaustive. Elaborating on any of the 848 listed approaches is deployment /solution specific and is not 849 considered in the current document. 851 4.3.1. Client-side initiated Re-Authorization 853 The Authorizing Entity provides the duration of the authorization 854 session as part of the QoS-Authorization-Answer message (QAA). At 855 any time before expiration of this period, a new QoS-Authorization- 856 Request message (QAR) MAY be sent to the Authorizing Entity. The 857 transmission of the QAR MAY be triggered when the Network Element 858 receives a QoS signaling message that requires modification of the 859 authorized parameters of an ongoing QoS session, when authorization 860 lifetime expires or by an accounting event. (see Section 5)(Figure 8) 861 Authorizing 862 End-Host Network Element Entity 863 requesting QoS ( Diameter ( Diameter 864 QoS Client) QoS Server) 865 | | | 866 |=====================Data Flow==========================> 867 | | | 868 | +-------+----------+ | 869 | |Authz-time/CC-Time| | 870 | | expires | | 871 | +-------+----------+ | 872 | +- - - - - QAR - - - - - >| 873 | |(QoS-Resources,Cost, | 874 | | QoS-Auth-Data,User-ID)| 875 | +--------+--------------+ 876 NOTE: | | Authorize request | 877 Re-authorization | | Update session data | 878 is transparent to | |/Authz-time,Session-Id/| 879 the End-Host | +--------+--------------+ 880 |< - - - - QAA - - - - - -+ 881 | |(Result-Code,CC-Time,Cost| 882 | |QoS-Resources,Authz-time)| 883 | +-------+---------+ | 884 | |Update QoS state | | 885 | | + | | 886 | | Authz. session | | 887 | | /Authz-time, | | 888 | | CC-Time,Cost/ | | 889 | +-------+---------+ | 890 | | | 891 | +- - - - - ACR - - - - - >| 892 | |(INTRM,QoS-Resources,Cost| 893 | |CC-Time,Acc-Multisess-id)| 894 | | +--------+--------------+ 895 | | |Update of QoS resources| 896 | | |/CC-Time,Cost/ used | 897 | | +--------+--------------+ 898 | |< - - - - ACA - - - - - -+ 899 | | | 900 |=====================Data Flow==========================> 901 | | 903 Figure 8: QoS request re-authorization 905 4.3.2. Server-side initiated Re-Authorization 907 The Authorizing Entity MAY optionally initiate a QoS re-authorization 908 by issuing a Re-Auth-Request message (RAR) as defined in the Diameter 909 base protocol [RFC3588]. A Network Element client that receives such 910 a RAR message with Session-Id matching a currently active QoS session 911 acknowledges the request by sending the Re-Auth-Answer (RAA) message 912 and MUST initiate a QoS reservation re-authorization by sending a 913 QoS-Authorization-Request (QAR) message towards the Authorizing 914 entity. 916 4.4. Server-side initiated QoS parameter provisioning 918 In certain deployment scenarios (mostly applicable for local QoS 919 provision) an active control over the QoS resource and QoS enabled 920 data flows from the network side is required. Therefore, the 921 Authorizing Entity is enabled to update installed QoS parameters and 922 flow state at the Network Element by sending a QoS-Install Request 923 message (QIR). Network Elements MUST apply the updates and respond 924 with an QoS-Install Answer message (QIA). This functionality, for 925 example, allows the update of already authorized flow status of an 926 established QoS reservation due to a change at the application layer 927 session (Figure 9). 929 Authorizing 930 End-Host Network Element Entity 931 requesting QoS ( Diameter ( Diameter 932 QoS Client) QoS Server) 933 | | | 934 +===================+=Data Flow==========================> 935 | | +--------+--------------+ 936 | | |Data flow preemption | 937 | | +--------+--------------+ 938 | |< - - - - QIR - - - - - -+ 939 | |(QoS-Resources[QoS-Flow- | 940 | | -State=CLOSE]) | 941 | +-------+---------+ | 942 | |Update QoS state | | 943 | | + | | 944 | | Authz. session | | 945 | |/QoS-Flow-State= | | 946 | | CLOSE/ | | 947 | +-------+---------+ | 948 +====Data Flow=====>X | 949 | +- - - - - QIA - - - - - >| 950 | | (Result-Code) | 951 Figure 9: Server-side initiated QoS parameter provisioning 953 The Authorizing Entity MAY initiate a QoS authorization session 954 establishment and QoS reservation state installation (prior to a 955 request from a Network Element). This function requires that the 956 Authorizing Entity has knowledge of specific information identifying 957 the Network Element that should be contacted and the data flow for 958 which the QoS reservation should be established.(mostly applicable 959 for local scenarios) 961 4.5. Session Termination 963 4.5.1. Client-side initiated session termination 965 The authorization session for an installed QoS reservation state MAY 966 be terminated by the Diameter client by sending a Session- 967 Termination-Request message (STR) to the Diameter server. This is a 968 Diameter base protocol function and it is defined in [RFC3588]. 969 Session termination can be caused by a QoS signaling messaging 970 requesting deletion of the existing QoS reservation state or it can 971 be caused as a result of a soft-state expiration of the QoS 972 reservation state. After a successful termination of the 973 authorization session, final accounting messages MUST be exchanged 974 (Figure 10). It should be noted that the two sessions (authorization 975 and accounting) have independent management by the Diameter base 976 protocol, which allows for finalizing the accounting session after 977 the end of the authorization session. 979 Authorizing 980 End-Host Network Element Entity 981 requesting QoS ( Diameter ( Diameter 982 QoS Client) QoS Server) 983 | | | 984 |==Data Flow==>X /Stop of the data flow/ | 985 | | | 986 +---QoS-Reserve---->| | 987 | (Delete QoS +- - - - - STR - - - - - >| 988 | reservation) | +--------+--------------+ 989 | | | Remove authorization | 990 |<--QoS-Response----+ | session state | 991 | | +--------+--------------+ 992 |< - - - - STA - - - - - -+ 993 +-------+--------+ | 994 |Delete QoS state| 995 | Report final | 996 | accounting data| QoS Responder 997 +-------+--------+ Node 998 +----------QoS-Reserve-----....--->| 999 | (Delete QoS | 1000 | reservation) 1001 | 1002 +- - - - - ACR - - - - - >| 1003 |(FINAL,QoS-Resources,Cost| 1004 |CC-Time,Acc-Multisess-id)| 1005 | +--------+--------------+ 1006 | | Report for successful | 1007 | | end of QoS session | 1008 | +--------+--------------+ 1009 |< - - - - ACA - - - - - -+ 1010 | 1011 | QoS Responder 1012 | Node 1013 |<---------QoS-Response----....----+ 1014 | | 1016 Figure 10: Client-side initiated session termination 1018 4.5.2. Server-side initiated session termination 1020 At anytime during a session the Authorizing Entity MAY send an Abort- 1021 Session-Request message (ASR) to the Network Element. This is a 1022 Diameter base protocol function and it is defined in [RFC3588]. 1023 Possible reasons for initiating the ASR message to the Network 1024 Element are insufficient credits or session termination at the 1025 application layer. The ASR message results in termination of the 1026 authorized session, release of the reserved resources at the Network 1027 Element and transmission of an appropriate QoS signaling message 1028 indicating a notification to other Network Elements aware of the 1029 signaling session. A final accounting message exchange MUST be 1030 triggered as a result of this ASR message exchange (Figure 11). 1032 Authorizing 1033 End-Host Network Element Entity 1034 requesting QoS ( Diameter ( Diameter 1035 QoS Client) QoS Server) 1036 | | | 1037 |=====================Data Flow==========================> 1038 | | 1039 | |< - - - - ASR - - - - - -+ 1040 | | | 1041 |====Data Flow=====>X | QoS Responder 1042 | | | Node 1043 |<--QoS-Notify------+----------QoS-Reserve-----....--->| 1044 | | (Delete QoS | | 1045 | reservation) | 1046 +-------+--------+ | 1047 |Delete QoS state| | 1048 | Report final | | 1049 | accounting data| | 1050 +-------+--------+ | 1051 +- - - - - ASA - - - - - >| 1052 | +--------+--------------+ 1053 | | Remove authorization | 1054 | | session state | 1055 | +--------+--------------+ 1056 +- - - - - ACR - - - - - >| 1057 |(FINAL,QoS-Resources,Cost| 1058 |CC-Time,Acc-Multisess-id)| 1059 | +--------+--------------+ 1060 | | Report for successful | 1061 | | end of QoS session | 1062 | +--------+--------------+ 1063 |< - - - - ACA - - - - - -+ 1064 | QoS Responder 1065 | Node 1066 |<---------QoS-Response----....----+ 1067 | | 1069 Figure 11: Server-side initiated session termination 1071 5. Accounting 1073 The Diameter QoS application provides accounting for usage of 1074 reserved QoS resources. Diameter QoS accounting has built-in support 1075 for online, duration based accounting. This accounting is based on 1076 the notion that the routers making the QoS Authorization Request 1077 (Diameter QoS clients) are in the best position to determine the cost 1078 of those resources. This cost represents the financial settlement 1079 that will be ultimately demanded by the owner of the router if the 1080 Resource Authorizing Entity authorizes the reservation. 1082 In the Diameter QoS application, the router MAY send a Cost- 1083 Information AVP ([RFC4006]) in the QAR. If the Cost-Information AVP 1084 includes a Cost-Unit AVP ([RFC4006]) then the Cost-Unit SHOULD be 1085 "minute". The Cost-Information AVPs represent the cost to allocate 1086 the resources requested in the QoS-Authorization-Resources AVP 1087 included in the same QAR message. The QAR MAY optionally contain a 1088 Tariff-Time-Change AVP ([RFC4006]) which is the time at which the 1089 cost will change, a second Cost-Information AVP, which is the cost of 1090 the reserved resources after the tariff time change, and a second 1091 Tariff-Time-Change, which is the time at which the tariff would 1092 change again. Either all three or none of these AVPs MUST be present 1093 in the QAR. 1095 The Resource Authorizing Entity returns a CC-Time AVP ([RFC4006]) in 1096 the QAA message which is the total authorized gate-on time for the 1097 service. If the QAR included two Tariff-Time-Change AVPs, the 1098 current time plus the CC-Time AVP returned in the QAA MUST NOT exceed 1099 the second Tariff-Time-Change AVP from the QAR. Based on information 1100 in the Cost-Information AVPs, the Resource Authorizing Entity can use 1101 the CC-Time AVP to guarantee that the total cost of the session will 1102 not exceed a certain threshold, which allows, for example, support of 1103 prepaid users. 1105 Each ACR message contains a triplet of QoS-Authorization-Resources 1106 AVP, Cost-Information AVP, and CC-Time AVP. This represents the 1107 total time consumed at the given cost for the given resources. Note 1108 that an ACR message MUST be sent separately for each interval defined 1109 by the Tariff-Time-Change AVPs and the expiration of the CC-Time 1110 returned in the QAA (Figure 8). 1112 The Network Element starts an accounting session by sending an 1113 Accounting-Request message (ACR) after successful QoS reservation and 1114 activation of the data flow (Figure 7). After every successful re- 1115 authorization procedure the Network element MUST initiate an interim 1116 accounting message exchange (Figure 8). After successful session 1117 termination the Network element MUST initiate a final exchange of 1118 accounting messages for terminating of the accounting session and 1119 reporting final records for the usage of the QoS resources reserved. 1120 (Figure 10). 1122 6. Diameter QoS authorization application Messages 1124 The Diameter QoS Application requires the definition of new mandatory 1125 AVPs and Command-codes (Section 3 of [RFC3588]). Four new Diameter 1126 messages are defined along with Command-Codes whose values MUST be 1127 supported by all Diameter implementations that conform to this 1128 specification. 1130 Command-Name Abbrev. Code Reference 1131 QoS-Authz-Request QAR [TBD] Section 6.1 1132 QoS-Authz-Answer QAA [TBD] Section 6.2 1133 QoS-Install-Request QIR [TBD] Section 6.3 1134 QoS-Install-Answer QIA [TBD] Section 6.4 1136 In addition, the following Diameter Base protocol messages are used 1137 in the Diameter QoS application: 1139 Command-Name Abbrev. Code Reference 1140 Accounting-Request ACR 271 RFC 3588 1141 Accounting-Request ACR 271 RFC 3588 1142 Accounting-Answer ACA 271 RFC 3588 1143 Re-Auth-Request RAR 258 RFC 3588 1144 Re-Auth-Answer RAA 258 RFC 3588 1145 Abort-Session-Request ASR 274 RFC 3588 1146 Abort-Session-Answer ASA 274 RFC 3588 1147 Session-Term-Request STR 275 RFC 3588 1148 Session-Term-Answer STA 275 RFC 3588 1150 Diameter nodes conforming to this specification MAY advertise support 1151 by including the value of TBD in the Auth-Application-Id or the Acct- 1152 Application-Id AVP of the Capabilities-Exchange-Request and 1153 Capabilities-Exchange-Answer commands [RFC3588]. 1155 The value of TBD MUST be used as the Application-Id in all QAR/QAA 1156 and QIR/QIA commands. 1158 The value of TBD MUST be used as the Application-Id in all ACR/ACA 1159 commands, because this application defines new, mandatory AVPs for 1160 accounting. 1162 The value of zero (0) SHOULD be used as the Application-Id in all 1163 STR/STA, ASR/ASA, and RAR/RAA commands, because these commands are 1164 defined in the Diameter base protocol and no additional mandatory 1165 AVPs for those commands are defined in this document. 1167 6.1. QoS-Authorization Request (QAR) 1169 The QoS-Authorization-Request message (QAR) indicated by the Command- 1170 Code field (Section 3 of [RFC3588]) set to TBD and 'R' bit set in the 1171 Command Flags field is used by Network elements to request quality of 1172 service related resource authorization for a given flow. 1174 The QAR message MUST carry information for signaling session 1175 identification, Authorizing Entity identification, information about 1176 the requested QoS, and the identity of the QoS requesting entity. In 1177 addition, depending on the deployment scenario, an authorization 1178 token and credentials of the QoS requesting entity SHOULD be 1179 included. 1181 The message format, presented in ABNF form [RFC2234], is defined as 1182 follows: 1184 ::= < Diameter Header: XXX, REQ, PXY > 1185 < Session-Id > 1186 { Auth-Application-Id } 1187 { Origin-Host } 1188 { Origin-Realm } 1189 { Destination-Realm } 1190 { Auth-Request-Type } 1191 [ Destination-Host ] 1192 [ User-Name ] 1193 * [ QoS-Authorization-Resources ] 1194 [ QoS-Authentication-Data ] 1195 [ Cost-Information ] 1196 [ Acc-Multisession-Id ] 1197 [ Bound-Auth-Session-Id ] 1198 * [ AVP ] 1200 6.2. QoS-Authorization Answer (QAA) 1202 The QoS-Authorization-Answer message (QAA), indicated by the Command- 1203 Code field set to TBD and 'R' bit cleared in the Command Flags field 1204 is sent in response to the QoS-Authorization-Request message (QAR). 1205 If the QoS authorization request is successfully authorized, the 1206 response will include the AVPs to allow authorization of the QoS 1207 resources as well as accounting and transport plane gating 1208 information. 1210 The message format is defined as follows: 1212 ::= < Diameter Header: XXX, PXY > 1213 < Session-Id > 1214 { Auth-Application-Id } 1215 { Auth-Request-Type } 1216 { Result-Code } 1217 { Origin-Host } 1218 { Origin-Realm } 1219 * [ QoS-Authorization-Resources ] 1220 [ CC-Time ] 1221 [ Acc-Multisession-Id ] 1222 [ Session-Timeout ] 1223 [ Authz-Session-Lifetime ] 1224 [ Authz-Grace-Period ] 1225 * [ AVP ] 1227 6.3. QoS-Install Request (QIR) 1229 The QoS-Install Request message (QIR), indicated by the Command-Code 1230 field set to TDB and 'R' bit set in the Command Flags field is used 1231 by Authorizing entity to install or update the QoS parameters and the 1232 flow state of an authorized flow at the transport plane element. 1234 The message MUST carry information for signaling session 1235 identification or identification of the flow to which the provided 1236 QoS rules apply, identity of the transport plane element, description 1237 of provided QoS parameters, flow state and duration of the provided 1238 authorization. 1240 The message format is defined as follows: 1242 ::= < Diameter Header: XXX, REQ, PXY > 1243 < Session-Id > 1244 { Auth-Application-Id } 1245 { Origin-Host } 1246 { Origin-Realm } 1247 { Destination-Realm } 1248 { Auth-Request-Type } 1249 [ Destination-Host ] 1250 * [ QoS-Authorization-Resources ] 1251 [ Session-Timeout ] 1252 [ Authz-Session-Lifetime ] 1253 [ Authz-Grace-Period ] 1254 [ Authz-Session-Volume ] 1255 * [ AVP ] 1257 6.4. QoS-Install Answer (QIA) 1259 The QoS-Install Answer message (QIA), indicated by the Command-Code 1260 field set to TBD and 'R' bit cleared in the Command Flags field is 1261 sent in response to the QoS-Install Request message (QIR) for 1262 confirmation of the result of the installation of the provided QoS 1263 reservation instructions. 1265 The message format is defined as follows: 1267 ::= < Diameter Header: XXX, PXY > 1268 < Session-Id > 1269 { Auth-Application-Id } 1270 { Origin-Host } 1271 { Origin-Realm } 1272 { Result-Code } 1273 * [ QoS-Authorization-Resources ] 1274 * [ AVP ] 1276 6.5. Accounting Request (ACR) 1278 The Accounting Request message (ACR), indicated by the Command-Code 1279 field set to 271 and 'R' bit set in the Command Flags field is used 1280 by Network Element to report parameters of the authorized and 1281 established QoS reservation. 1283 The message MUST carry accounting information authorized QoS 1284 resources and its usage, e.g., QoS-Authorized-Resources, CC-Time, CC- 1285 Cost, Acc-Multi-Session-Id. 1287 The message format is defined as follows: 1289 ::= < Diameter Header: XXX, REQ, PXY > 1290 < Session-Id > 1291 { Acct-Application-Id } 1292 { Destination-Realm } 1293 [ Destination-Host ] 1294 [ Accounting-Record-Type ] 1295 [ Accounting-Record-Number ] 1296 * [ QoS-Authorization-Resources ] 1297 [ Cost-Information ] 1298 [ CC-Time ] 1299 [ Acc-Multi-Session-Id ] 1300 * [ AVP ] 1302 6.6. Accounting Answer (ACA) 1304 The Accounting Answer message (ACA), indicated by the Command-Code 1305 field set to 271 and 'R' bit cleared in the Command Flags field is 1306 sent in response to the Accounting Request message (ACR) as an 1307 acknowledgment of the ACR message and MAY carry additional management 1308 information for the accounting session, e.g. Acc-Interim-Interval 1309 AVP. 1311 The message format is defined as follows: 1313 ::= < Diameter Header: XXX, PXY > 1314 < Session-Id > 1315 { Acct-Application-Id } 1316 [ Result-Code ] 1317 [ Accounting-Record-Type ] 1318 [ Accounting-Record-Number ] 1319 [ Acc-Multi-Session-Id ] 1320 * [ AVP ] 1322 7. Diameter QoS Authorization Application AVPs 1324 Each of the AVPs identified in the QoS-Authorization-Request/Answer 1325 and QoS-Install-Request/Answer messages and the assignment of their 1326 value(s) is given in this section. 1328 7.1. Diameter Base Protocol AVPs 1330 The Diameter QoS application uses a number of session management 1331 AVPs, defined in the Base Protocol ([RFC3588]). 1333 Attribute Name AVP Code Reference [RFC3588] 1334 Origin-Host 264 Section 6.3 1335 Origin-Realm 296 Section 6.4 1336 Destination-Host 293 Section 6.5 1337 Destination-Realm 283 Section 6.6 1338 Auth-Application-Id 258 Section 6.8 1339 Result-Code 268 Section 7.1 1340 Auth-Request-Type 274 Section 8.7 1341 Session-Id 263 Section 8.8 1342 Authz-Lifetime 291 Section 8.9 1343 Authz-Grace-Period 276 Section 8.10 1344 Session-Timeout 27 Section 8.13 1345 User-Name 1 Section 8.14 1346 QoS-Filter-Rule 407 Section 6.9 [RFC4005] 1348 The Auth-Application-Id AVP (AVP Code 258) is assigned by IANA to 1349 Diameter applications. The value of the Auth-Application-Id for the 1350 Diameter QoS application is TBD. 1352 7.2. Credit Control application AVPs 1354 The Diameter QoS application provides accounting for usage of 1355 reserved QoS resources. Diameter QoS accounting has built-in support 1356 for online, duration based accounting. For this purpose it re-uses a 1357 number of AVPs defined in Diameter Credit Control application. 1358 [RFC4006]. 1360 Attribute Name AVP Code Reference [RFC4006] 1361 Cost-Information AVP 423 Section 8.7 1362 Unit-Value AVP 445 Section 8.8 1363 Currency-Code AVP 425 Section 8.11 1364 Cost-Unit AVP 424 Section 8.12 1365 CC-Time AVP 420 Section 8.21 1366 Tariff-Time-Change AVP 451 Section 6.20 1367 Usage of the listed AVPs is described in Section 5 1369 Diameter QoS application is designed to independently provide credit 1370 control over the controlled QoS resources. However, deployment 1371 scenarios, where Diameter QoS application is collocated with Diameter 1372 Credit Control application, are not excluded. In such scenarios the 1373 credit control over the QoS resources might be managed by the Credit 1374 control application. Possible interworking approach might be a usage 1375 of Credit-Control AVP (AVP Code 426) with a newly defined value. It 1376 will indicate to the Diameter QoS entities that the credit control 1377 over the QoS resources would be handled in separate session by Credit 1378 Control application. An active cooperation of both applications 1379 would be required but it is not elaborated further in this document. 1381 7.3. Accounting AVPs 1383 The Diameter QoS application uses Diameter Accounting and accounting 1384 AVPs as defined in Section 9 of [RFC3588]. Additional description of 1385 the usage of some of them in the QoS authorization context is 1386 provided: 1388 Attribute Name AVP Code Reference [RFC3588] 1389 Acct-Application-Id 259 Section 6.9 1390 Accounting-Record-Type 480 Section 9.8.1 1391 Accounting-Interim-Interval 85 Section 9.8.2 1392 Accounting-Record-Number 485 Section 9.8.3 1393 Accounting-Realtime-Required 483 Section 9.8.7 1394 Acc-Multi-Session-ID 50 Section 9.8.5 1396 The following AVP needs further explanation: 1398 Acct-Application-Id AVP 1400 The Acct-Application-Id AVP (AVP Code 259)is assigned by IANA to 1401 Diameter applications. The value of the Acct-Application-Id for 1402 the Diameter QoS application is TBD (TBD). 1404 Acc-Multisession-ID 1406 Acc-Multi-Session-ID AVP (AVP Code 50) SHOULD be used to link 1407 multiple accounting sessions together, allowing the correlation of 1408 accounting information. This AVP MAY be returned by the Diameter 1409 server in a QoS-Authorization-Answer message (QAA), and MUST be 1410 used in all accounting messages for the given session. 1412 7.4. Diameter QoS Application Defined AVPs 1414 This section defines the Quality of Service AVPs that are specific to 1415 the Diameter QoS application and MAY be included in the Diameter QoS 1416 application messages. Unlike the approach followed with RSVP (see 1417 [RFC2749]), where the entire RSVP message is encapsulated into a COPS 1418 message, only the relevant fields SHOULD be included. This approach 1419 avoids a certain overhead of transmitting fields which are irrelevant 1420 for the AAA infrastructure. It keeps implementations simpler and it 1421 allows the reuse of other Diameter AVPs. 1423 The following table describes the Diameter AVPs in the QoS 1424 Application, their AVP code values, types, possible flag values, and 1425 whether the AVP MAY be encrypted. 1427 | AVP Flag rules | 1428 +----------------------------------------------|----+---+----+-----+ 1429 | AVP Section | | |SHLD| MUST| 1430 | Attribute Name Code Defined Data Type |MUST|MAY| NOT| NOT| 1431 +----------------------------------------------+----+---+----+-----+ 1432 |Signaling-Session-Id TBD 7.4 Unsigned32 | M | P | | V | 1433 |Flow-ID TBD 7.4 Unsigned32 | M | P | | V | 1434 |SPI TBD 7.4 Unsigned32 | M | P | | V | 1435 |QoS-Flow-State TBD 7.4 Enumerated | M | P | | V | 1436 |IND-Flow TBD 7.4 Grouped | M | P | | V | 1437 |Flows TBD 7.4 Grouped | M | P | | V | 1438 |QSPEC TBD 7.4 OctetString| M | P | | V | 1439 |QoS-Auth-Resources TBD 7.4 Grouped | M | P | | V | 1440 |QoS-Auth-Data TBD 7.4 Grouped | M | P | | V | 1441 |Bound-Auth-Session-Id TBD 7.4 UTF8String | M | P | | V | 1442 +----------------------------------------------+----+---+----+-----+ 1443 |M - Mandatory bit. An AVP with "M" bit set and its value MUST be | 1444 | supported and recognized by a Diameter entity in order the | 1445 | message, which carries this AVP, to be accepted. | 1446 |P - Indicates the need for encryption for end-to-end security. | 1447 |V - Vendor specific bit that indicates whether the AVP belongs to | 1448 | a address space. | 1449 +------------------------------------------------------------------+ 1451 Signaling-Session-ID 1453 Signaling-Session-ID AVP (AVP Code TBD) is of type Unsigned32 and 1454 is derived from the QoS signaling session identifier, which is a 1455 unique identifier of the QoS signaling session that in the NSIS 1456 case remains unchanged for the duration of the session. 1458 Flow-ID 1460 The Flow-ID AVP (AVP Code TBD) is of type Unsigned32 and contains 1461 identifier of an IP flow. 1463 SPI 1465 The SPI AVP (AVP Code TBD) is of type Unsigned32 and extends the 1466 QoS-Filter-Rule AVP to support IPsec protected traffic. 1468 QoS-Flow-State 1470 The QoS-Flow-State AVP (AVP Code TBD) is of type Enumerated. It 1471 gives an indication by the Authorizing entity as to how the flow 1472 MUST be treated. When included in a QAA message, it contains an 1473 action to be performed on the state of the flow to which the 1474 message applies. The values supported are: 1476 0 Open - Enable the transport plane service, for which 1477 the signaling has been performed. 1478 1 Close - Disable the transport plane service 1479 2 Maintain - Do not alter the current state (enabled/disabled) 1480 of the transport plane service. 1482 The QoS-Flow-State is an optional AVP. When not included in a QAA 1483 response, the default behavior is to immediately allow the flow of 1484 packets (Open). 1486 The behavior of Close (0) for the QoS-Flow-State refers to the 1487 case where a QoS reservation exists but it is not activated and 1488 therefore not charged. For time-based charging the time interval 1489 where the gate is closed will not be included of the chargeable 1490 time interval. The QoS model might give some indication whether 1491 an established QoS reservation needs to be freed or needs to be 1492 removed only if not enough resources are available. 1494 IND-Flows 1496 The IND-Flows AVP (AVP Code TBD) is of type Grouped and specifies 1497 an IP flow via its flow identifier and/or filter-rule. Note that 1498 more than one IP flow may be described if only QoS-Filter-Rule is 1499 used. 1501 IND-Flows ::= 1502 [Flow-Id] 1503 [QoS-Filter-Rule] 1504 [SPI] 1506 Flows 1508 The Flows AVP (AVP Code TBD) is of type Grouped and contains all 1509 the individual flows that receive the same QoS specified in the 1510 QPSEC AVP included in the QoS-Authorization-Resources AVP. 1512 Flows ::= < AVP Header: XXX > 1513 1* [ IND-Flows ] 1515 QSPEC 1517 The QSPEC AVP (AVP Code TBD) is of type OctetString and contains 1518 QoS parameter information. The description format is taken from 1519 QoS NSLP Qspec template, which is expected to cover all present 1520 QoS description methods [I-D.ietf-nsis-qspec]. 1522 QoS-Authorization-Resources 1524 The QoS-Auth-Resources AVP (AVP Code TBD) is of type Grouped and 1525 includes description of the resources that have been requested by 1526 the user or authorized by the application server for a particular 1527 QoS request. More than one MAY be included into a message. 1529 QoS-Auth-Resources ::= < AVP Header: XXX > 1530 [ Signaling-Session-ID ] 1531 [ Flows ] 1532 [ QSPEC ] 1533 [ QoS-Flow-State ] 1535 The three types of identifiers for the QoS signaling session (i.e, 1536 Signaling-Session-ID, Flow-ID and OoSFilter-Rule with SPI) SHOULD 1537 be used separately when included in the QoS-Authorization-Request 1538 (QAR) messages. 1540 QoS-Authentication-Data 1542 The QoS-Authentication-Data AVP (AVP Code TBD) is of type 1543 OctetString. It is a container that carries application session 1544 or user specific data that has to be supplied to the Authorizing 1545 entity as input to the computation of the authorization decision. 1547 Bound-Authentication-Session-Id 1549 The Bound-Authentication-Session AVP (AVP Code TBD) is of type 1550 UTF8String. It carries the id of the Diameter authentication 1551 session that is used for the network access authentication (NASREQ 1552 authentication session). It is used to tie the QoS authorization 1553 request to a prior authentication of the end host done by a co- 1554 located application for network access authentication (Diameter 1555 NASREQ) at the QoS NE. 1557 8. Examples 1559 This section presents an example of the interaction between the 1560 application layer signaling and the QoS signaling along the data 1561 path. The application layer signaling is, in this example, provided 1562 using SIP. Signaling for a QoS resource reservation is done using 1563 the QoS NSLP. The authorization of the QoS reservation request is 1564 done by the Diameter QoS application (DQA). 1566 End-Host SIP Server Correspondent 1567 requesting QoS (DQA Server) Node 1569 | | | 1570 ..|....Application layer SIP signaling.......|..............|.. 1571 . | Invite (SDP) | | . 1572 . +.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-> | . 1573 . | 100 Trying | | . 1574 . <.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-+ Invite (SDP)| . 1575 . | +-.-.-.....-.-.> . 1576 . | | 180 SDP' | . 1577 . | <-.-.-.....-.-.+ . 1578 . | +--------+--------+ | . 1579 . | |Authorize session| | . 1580 . | | parameters | | . 1581 . | 180 (Session parameters) +--------+--------+ | . 1582 . <.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-+ | . 1583 ..|..........................................|... ..........|.. 1584 | | | 1585 | +------------+ | | 1586 | | NE | | | 1587 | |(DQA Client)| | | 1588 | +------+-----+ | | 1589 | | | | 1590 |QoS NSLP Reserve | | | 1591 +------------------> QAR | | 1592 | (POLICY_DATA>v +- - - - -<>- - - -> | 1593 | QSPEC) v >===>(Destination-Host, | | 1594 | v >=======>QoS-Auth-Data, ++------------+ | 1595 | >===========>QoS-Authz-Resources, |Authorize | | 1596 | |Cost-Info) |QoS resources| | 1597 | | ++------------+ | 1598 | | QAA | | 1599 | <- - - - -<>- - - -+ | 1600 | |(Result-Code, | | 1601 | |QoS-Authz-Resources, | | 1602 | |CC-Time, | | 1603 | |Authz-Lifetime) | | 1604 | +---------+--------+ | | 1605 | |Install QoS state1| | | 1606 | |+ Authz. session | | | 1607 | +---------+--------+ | | 1608 | |QoS NSLP Reserve | 1609 | +---------------..............---------> 1610 | | | 1611 | | QoS NSLP Response| 1612 |QoS NSLP Response <---------------..............---------+ 1613 <------------------+ | 1614 | | QoS NSLP Query| 1615 |QoS NSLP Query <---------------..............---------+ 1616 <------------------+ | 1617 |QoS NSLP Reserve | | 1618 +------------------> QAR | | 1619 | +- - - - -<>- - - -> | 1620 | | +---+---------+ | 1621 | | |Authorize | | 1622 | | |QoS resources| | 1623 | | QAA +---+---------+ | 1624 | <- - - - -<>- - - -+ | 1625 | +---------+--------+ | | 1626 | |Install QoS state2| | 1627 | |+ Authz. session | | 1628 | +---------+--------+ | 1629 | | QoS NSLP Reserve | 1630 | +---------------..............---------> 1631 | | QoS NSLP Response| 1632 |QoS NSLP Response <---------------..............---------+ 1633 <------------------+ | 1634 | | | 1635 /------------------+--Data Flow---------------------------\ 1636 \------------------+--------------------------------------/ 1637 | | | 1639 .-.-.-.-. SIP signaling 1640 --------- QoS NSLP signaling 1641 - - - - - Diameter QoS Application messages 1642 ========= Mapping of objects between QoS and AAA protocol 1644 Figure 28: Example for a token-based QoS authorization 1646 The communication starts with SIP signaling between the two end 1647 points and the SIP server for negotiation and authorization of the 1648 requested service and its parameters (Figure 28). As a part of the 1649 process, the SIP server verifies whether the user at Host A is 1650 authorized to use the requested service (and potentially the ability 1651 to be charged for the service usage). Negotiated session parameters 1652 are provided to the end host. 1654 Subsequently, Host A initiates a QoS signaling message towards Host 1655 B. It sends a QoS NSLP Reserve message, in which it includes 1656 description of the required QoS (QSPEC object) and authorization data 1657 for negotiated service session (part of the POLICY_DATA object). 1658 Authorization data includes, as a minimum, the identity of the 1659 authorizing entity (e.g., the SIP server) and an identifier of the 1660 application service session for which QoS resources are requested. 1662 A QoS NSLP Reserve message is intercepted and processed by the first 1663 QoS aware Network Element. The NE uses the Diameter QoS application 1664 to request authorization for the received QoS reservation request. 1665 The identity of the Authorizing Entity (in this case the SIP server 1666 that is co-located with a Diameter server) is put into the 1667 Destination-Host AVP, any additional session authorization data is 1668 encapsulated into the QoS-Authentication AVP and the description of 1669 the QoS resources is included into QoS-Authorized-Resources AVP. In 1670 addition, the NE rates the requested QoS resources and announces the 1671 charging rate into the Cost-Information AVP. These AVPs are included 1672 into a QoS Authorization Request message, which is sent to the 1673 Authorizing entity. 1675 A Diameter QAR message will be routed through the AAA network to the 1676 Authorizing Entity. The Authorizing Entity verifies the requested 1677 QoS against the QoS resources negotiated for the service session and 1678 replies with QoS-Authorization answer (QAA) message. It carries the 1679 authorization result (Result-Code AVP) and the description of the 1680 authorized QoS parameters (QoS-Authorized-Resources AVP), as well as 1681 duration of the authorization session (Authorization-Lifetime AVP) 1682 and duration of the time (CC-Time) for which the end-user should be 1683 charged with the rate announced in the QAR message. The NE interacts 1684 with the traffic control function and installs the authorized QoS 1685 resources and forwards the QoS NSLP Reserve message further along the 1686 data path. 1688 Note that the example above shows a sender-initiated reservation from 1689 the End-Host towards the corresponding node and a receiver-initiated 1690 reservation from the correspondent node towards the End-Host. 1692 9. Security Considerations 1694 This document describes a mechanism for performing authorization of a 1695 QoS reservation at a third party entity. Therefore, it is necessary 1696 the QoS signaling application to carry sufficient information that 1697 should be forwarded to the backend AAA server. This functionality is 1698 particularly useful in roaming environments where the authorization 1699 decision is most likely provided at an entity where the user can be 1700 authorized, such as in the home realm. 1702 QoS signaling application MAY re-use the authenticated identities 1703 used for the establishment of the secured transport channel for the 1704 signaling messages, e.g., TLS or IPsec between the end host and the 1705 policy aware QoS NE. In addition, a collocation of the QoS NE with, 1706 for example, the Diameter NASREQ application ([RFC4005]) may allow 1707 the QoS authorization to be based on the authenticated identity used 1708 during the network access authentication protocol run. If a co- 1709 located deployment is not desired then special security protection is 1710 required to ensure that arbitrary nodes cannot reuse a previous 1711 authentication exchange to perform an authorization decision. 1713 Additionally, QoS authorization might be based on the usage of 1714 authorization tokens that are generated by the Authorizing Entity and 1715 provided to the end host via application layer signaling. 1717 The impact of the existence of different authorization models is 1718 (with respect to this Diameter QoS application) the ability to carry 1719 different authentication and authorization information. Further 1720 discussions on the authorization handling for QoS signaling protocols 1721 is available with [I-D.tschofenig-nsis-aaa-issues] and 1722 [I-D.tschofenig-nsis-qos-authz-issues]. 1724 10. Acknowledgements 1726 The authors would like to thank John Loughney and Allison Mankin for 1727 their input to this document. In September 2005 Robert Hancock, 1728 Jukka Manner, Cornelia Kappler, Xiaoming Fu, Georgios Karagiannis and 1729 Elwyn Davies provided a detailed review. Robert also provided us 1730 with good feedback earlier in 2005. Jerry Ash provided us review 1731 comments late 2005/early 2006. 1733 11. Open Issues 1735 Open issues related to this draft are listed at the issue tracker 1736 available at: http://www.tschofenig.com:8080/diameter-qos/ 1738 12. References 1740 12.1. Normative References 1742 [I-D.ietf-nsis-qspec] 1743 Ash, J., "QoS NSLP QSPEC Template", 1744 draft-ietf-nsis-qspec-12 (work in progress), October 2006. 1746 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1747 Requirement Levels", BCP 14, RFC 2119, March 1997. 1749 [RFC2234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax 1750 Specifications: ABNF", RFC 2234, November 1997. 1752 [RFC3588] Calhoun, P., Loughney, J., Guttman, E., Zorn, G., and J. 1753 Arkko, "Diameter Base Protocol", RFC 3588, September 2003. 1755 [RFC4005] Calhoun, P., Zorn, G., Spence, D., and D. Mitton, 1756 "Diameter Network Access Server Application", RFC 4005, 1757 August 2005. 1759 [RFC4006] Hakala, H., Mattila, L., Koskinen, J-P., Stura, M., and J. 1760 Loughney, "Diameter Credit-Control Application", RFC 4006, 1761 August 2005. 1763 12.2. Informative References 1765 [ETSI-OSP] 1766 European Telecommunications Standards Institute, 1767 "Telecommunications and Internet Protocol Harmonization 1768 Over Networks (TIPHON); Open Settlement Protocol (OSP) 1769 for Inter-domain pricing, authorization, and usage 1770 exchange", TS 101 321. 1772 [I-D.ietf-nsis-ntlp] 1773 Schulzrinne, H. and R. Hancock, "GIST: General Internet 1774 Signaling Transport", draft-ietf-nsis-ntlp-11 (work in 1775 progress), August 2006. 1777 [I-D.ietf-nsis-qos-nslp] 1778 Manner, J., "NSLP for Quality-of-Service Signaling", 1779 draft-ietf-nsis-qos-nslp-11 (work in progress), June 2006. 1781 [I-D.ietf-sipping-trait-authz] 1782 Peterson, J., "Trait-based Authorization Requirements for 1783 the Session Initiation Protocol (SIP)", 1784 draft-ietf-sipping-trait-authz-02 (work in progress), 1785 January 2006. 1787 [I-D.tschofenig-nsis-aaa-issues] 1788 Tschofenig, H., "NSIS Authentication, Authorization and 1789 Accounting Issues", draft-tschofenig-nsis-aaa-issues-01 1790 (work in progress), March 2003. 1792 [I-D.tschofenig-nsis-qos-authz-issues] 1793 Tschofenig, H., "QoS NSLP Authorization Issues", 1794 draft-tschofenig-nsis-qos-authz-issues-00 (work in 1795 progress), June 2003. 1797 [I-D.tschofenig-sip-saml] 1798 Tschofenig, H., "SIP SAML Profile and Binding", 1799 draft-tschofenig-sip-saml-05 (work in progress), 1800 March 2006. 1802 [RFC2210] Wroclawski, J., "The Use of RSVP with IETF Integrated 1803 Services", RFC 2210, September 1997. 1805 [RFC2327] Handley, M. and V. Jacobson, "SDP: Session Description 1806 Protocol", RFC 2327, April 1998. 1808 [RFC2486] Aboba, B. and M. Beadles, "The Network Access Identifier", 1809 RFC 2486, January 1999. 1811 [RFC2749] Herzog, S., Boyle, J., Cohen, R., Durham, D., Rajan, R., 1812 and A. Sastry, "COPS usage for RSVP", RFC 2749, 1813 January 2000. 1815 [RFC2753] Yavatkar, R., Pendarakis, D., and R. Guerin, "A Framework 1816 for Policy-based Admission Control", RFC 2753, 1817 January 2000. 1819 [RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson, 1820 "Remote Authentication Dial In User Service (RADIUS)", 1821 RFC 2865, June 2000. 1823 [RFC3313] Marshall, W., "Private Session Initiation Protocol (SIP) 1824 Extensions for Media Authorization", RFC 3313, 1825 January 2003. 1827 [RFC3520] Hamer, L-N., Gage, B., Kosinski, B., and H. Shieh, 1828 "Session Authorization Policy Element", RFC 3520, 1829 April 2003. 1831 [RFC3521] Hamer, L-N., Gage, B., and H. Shieh, "Framework for 1832 Session Set-up with Media Authorization", RFC 3521, 1833 April 2003. 1835 [RFC4027] Josefsson, S., "Domain Name System Media Types", RFC 4027, 1836 April 2005. 1838 Authors' Addresses 1840 Frank M. Alfano 1841 Lucent Technologies 1842 1960 Lucent Lane 1843 Naperville, IL 60563 1844 USA 1846 Phone: +1 630 979 7209 1847 Email: falfano@lucent.com 1849 Peter J. McCann 1850 Lucent Technologies 1851 1960 Lucent Lane 1852 Naperville, IL 60563 1853 USA 1855 Phone: +1 630 713 9359 1856 Email: mccap@lucent.com 1858 Hannes Tschofenig 1859 Siemens 1860 Otto-Hahn-Ring 6 1861 Munich, Bavaria 81739 1862 Germany 1864 Email: Hannes.Tschofenig@siemens.com 1865 URI: http://www.tschofenig.com 1867 Tseno Tsenov 1868 Sofia, 1869 Bulgaria 1871 Email: tseno.tsenov@mytum.de 1873 Tina Tsou 1874 Shenzhen, 1875 P.R.C 1877 Email: tena@huawei.com 1879 Full Copyright Statement 1881 Copyright (C) The Internet Society (2006). 1883 This document is subject to the rights, licenses and restrictions 1884 contained in BCP 78, and except as set forth therein, the authors 1885 retain all their rights. 1887 This document and the information contained herein are provided on an 1888 "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS 1889 OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET 1890 ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, 1891 INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE 1892 INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED 1893 WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 1895 Intellectual Property 1897 The IETF takes no position regarding the validity or scope of any 1898 Intellectual Property Rights or other rights that might be claimed to 1899 pertain to the implementation or use of the technology described in 1900 this document or the extent to which any license under such rights 1901 might or might not be available; nor does it represent that it has 1902 made any independent effort to identify any such rights. Information 1903 on the procedures with respect to rights in RFC documents can be 1904 found in BCP 78 and BCP 79. 1906 Copies of IPR disclosures made to the IETF Secretariat and any 1907 assurances of licenses to be made available, or the result of an 1908 attempt made to obtain a general license or permission for the use of 1909 such proprietary rights by implementers or users of this 1910 specification can be obtained from the IETF on-line IPR repository at 1911 http://www.ietf.org/ipr. 1913 The IETF invites any interested party to bring to its attention any 1914 copyrights, patents or patent applications, or other proprietary 1915 rights that may cover technology that may be required to implement 1916 this standard. Please address the information to the IETF at 1917 ietf-ipr@ietf.org. 1919 Acknowledgment 1921 Funding for the RFC Editor function is provided by the IETF 1922 Administrative Support Activity (IASA).