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Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group G. Zorn, Ed. 3 Internet-Draft Cisco Systems 4 Intended status: Standards Track P. McCann 5 Expires: January 10, 2008 Motorola Labs 6 H. Tschofenig 7 Nokia Siemens Networks 8 T. Tsou 9 Huawei 10 A. Doria 11 Lulea University of Technology 12 D. Sun 13 Bell Labs/Alcatel-Lucent 14 July 9, 2007 16 Diameter Quality of Service Application 17 draft-ietf-dime-diameter-qos-01.txt 19 Status of this Memo 21 By submitting this Internet-Draft, each author represents that any 22 applicable patent or other IPR claims of which he or she is aware 23 have been or will be disclosed, and any of which he or she becomes 24 aware will be disclosed, in accordance with Section 6 of BCP 79. 26 Internet-Drafts are working documents of the Internet Engineering 27 Task Force (IETF), its areas, and its working groups. Note that 28 other groups may also distribute working documents as Internet- 29 Drafts. 31 Internet-Drafts are draft documents valid for a maximum of six months 32 and may be updated, replaced, or obsoleted by other documents at any 33 time. It is inappropriate to use Internet-Drafts as reference 34 material or to cite them other than as "work in progress." 36 The list of current Internet-Drafts can be accessed at 37 http://www.ietf.org/ietf/1id-abstracts.txt. 39 The list of Internet-Draft Shadow Directories can be accessed at 40 http://www.ietf.org/shadow.html. 42 This Internet-Draft will expire on January 10, 2008. 44 Copyright Notice 46 Copyright (C) The IETF Trust (2007). 48 Abstract 50 This document describes a Diameter application that performs 51 Authentication, Authorization, and Accounting for Quality of Service 52 (QoS) reservations. This protocol is used by elements along the path 53 of a given application flow to authenticate a reservation request, 54 ensure that the reservation is authorized, and to account for 55 resources consumed during the lifetime of the application flow. 56 Clients that implement the Diameter QoS application contact an 57 authorizing entity/application server that is located somewhere in 58 the network, allowing for a wide variety of flexible deployment 59 models. 61 Table of Contents 63 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5 64 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 6 65 3. Framework . . . . . . . . . . . . . . . . . . . . . . . . . . 8 66 3.1. Network element functional model . . . . . . . . . . . . . 9 67 3.2. Implications of endpoint QoS capabilities . . . . . . . . 11 68 3.2.1. Category of endpoint QoS capabilities . . . . . . . . 11 69 3.2.2. Interaction modes between authorizing entity and 70 network element . . . . . . . . . . . . . . . . . . . 11 71 3.3. Authorization schemes . . . . . . . . . . . . . . . . . . 13 72 3.3.1. Authorization schemes for pull mode . . . . . . . . . 13 73 3.3.2. Authorization schemes for push mode . . . . . . . . . 16 74 3.4. QoS Authorization Requirements . . . . . . . . . . . . . . 17 75 4. Diameter QoS Authorization Session Establishment and 76 Management . . . . . . . . . . . . . . . . . . . . . . . . . . 22 77 4.1. Parties involved . . . . . . . . . . . . . . . . . . . . . 22 78 4.2. Diameter QoS Authorization Session Establishment . . . . . 22 79 4.3. QoS authorization session re-authorization . . . . . . . . 26 80 4.3.1. Client-Side Initiated Re-Authorization . . . . . . . . 26 81 4.3.2. Server-Side Initiated Re-Authorization . . . . . . . . 28 82 4.4. Server-Side Initiated QoS Parameter Provisioning . . . . . 28 83 4.5. Session Termination . . . . . . . . . . . . . . . . . . . 29 84 4.5.1. Client-Side Initiated Session Termination . . . . . . 29 85 4.5.2. Server-Side Initiated Session Termination . . . . . . 30 86 5. Accounting . . . . . . . . . . . . . . . . . . . . . . . . . . 32 87 6. Diameter QoS Authorization Application Messages . . . . . . . 33 88 6.1. QoS-Authorization Request (QAR) . . . . . . . . . . . . . 34 89 6.2. QoS-Authorization Answer (QAA) . . . . . . . . . . . . . . 34 90 6.3. QoS-Install Request (QIR) . . . . . . . . . . . . . . . . 35 91 6.4. QoS-Install Answer (QIA) . . . . . . . . . . . . . . . . . 36 92 6.5. Accounting Request (ACR) . . . . . . . . . . . . . . . . . 36 93 6.6. Accounting Answer (ACA) . . . . . . . . . . . . . . . . . 37 94 7. Diameter QoS Authorization Application AVPs . . . . . . . . . 38 95 7.1. Diameter Base Protocol AVPs . . . . . . . . . . . . . . . 38 96 7.2. Credit Control Application AVPs . . . . . . . . . . . . . 38 97 7.3. Accounting AVPs . . . . . . . . . . . . . . . . . . . . . 39 98 7.4. Diameter QoS Application Defined AVPs . . . . . . . . . . 39 99 8. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 100 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 44 101 10. Security Considerations . . . . . . . . . . . . . . . . . . . 45 102 11. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 46 103 12. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 47 104 13. Open Issues . . . . . . . . . . . . . . . . . . . . . . . . . 48 105 14. References . . . . . . . . . . . . . . . . . . . . . . . . . . 49 106 14.1. Normative References . . . . . . . . . . . . . . . . . . . 49 107 14.2. Informative References . . . . . . . . . . . . . . . . . . 49 108 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 51 109 Intellectual Property and Copyright Statements . . . . . . . . . . 53 111 1. Introduction 113 To meet the Quality of Service needs of applications such as Voice- 114 over-IP in a heavily loaded network, packets belonging to real-time 115 application flows must be identified and segregated from other 116 traffic to ensure that bandwidth, delay, and loss rate requirements 117 are met. In addition, new flows should not be added to the network 118 when it is at or near capacity, which would result in degradation of 119 quality for all flows carried by the network. 121 In some cases, these goals can be achieved with mechanisms such as 122 differentiated services and/or end-to-end congestion and admission 123 control. However, when bandwidth is scarce and must be carefully 124 managed, such as in cellular networks, or when applications and 125 transport protocols lack the capability to perform end-to-end 126 congestion control, explicit reservation techniques are required. In 127 these cases, the endpoints will send reservation requests to edge 128 and/or interior nodes along the communication path. In addition to 129 verifying whether resources are available, the recipient of a 130 reservation request must also authenticate and authorize the request, 131 especially in an environment where the endpoints are not trusted. In 132 addition, these nodes will generate accounting information about the 133 resources used and attribute usage to the requesting endpoints. This 134 will enable the owner of the network element to generate usage- 135 sensitive billing records and to understand how to allocate new 136 network capacity. 138 A variety of protocols could be used to make a QoS request, including 139 RSVP [RFC2210], NSIS [I-D.ietf-nsis-qos-nslp], link-specific 140 signaling or even SIP/SDP [RFC4566]. This document aims to be 141 agnostic to the QoS signaling protocol used and to the QoS model to 142 which the signaling is directed. 144 2. Terminology 146 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 147 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 148 document are to be interpreted as described in RFC 2119 [RFC2119]. 150 The following terms are used in this document: 152 Application Server 154 An application server is a network entity that exchanges signaling 155 messages with an application endpoint. It may be a source of 156 authorization for QoS-enhanced application flows. For example, a 157 SIP server is one kind of application server. 159 Application Endpoint 161 An application endpoint is an entity in an end user device that 162 exchanges signaling messages with application servers or directly 163 with other application endpoints. Based on the result of this 164 signaling, the endpoint may make a request for QoS from the 165 network. For example, a SIP User Agent is one kind of application 166 endpoint. 168 Authorizing Entity 170 The authorizing entity acts as a Diameter server (and may 171 collocate with a subscriber database) responsible for authorizing 172 QoS requests for a particular application flow or aggregate. It 173 may be a standalone entity or integrated with an application 174 server. This entity corresponds to the Policy Decision Point 175 (PDP) (see [RFC2753]). 177 AAA Cloud 179 An infrastructure of AAA entities (clients, agents, servers) based 180 on a AAA protocol, which provides trusted secure connections 181 between them. It offers authentication, authorization and 182 accounting services to applications in flexible local and roaming 183 scenarios. Diameter [RFC3588] and RADIUS [RFC2865] are both 184 widely deployed AAA protocols. 186 Network Element (NE) 188 QoS aware router that acts as Diameter client that implements the 189 Diameter QoS application in the context of this document. For 190 almost all scenarios this entity triggers the protocol interaction 191 described in this document. This entity corresponds to the Policy 192 Enforcement Point (PEP) (see [RFC2753]). 194 Pull Mode 196 In this mode, the QoS authorization process is invoked by the QoS 197 reservation request received from the endpoint. The Network 198 Element then requests the QoS authorization decision from the 199 Authorizing entity. 201 Push Mode 203 In this mode, the QoS authorization process is invoked by the 204 request from Application Server or local policies in the 205 Authorizing Entity. The Authorizing Entity then installs the QoS 206 authorization decision to the Network Element initiatively. 208 3. Framework 210 The Diameter QoS application runs between a network element (acting 211 as a Diameter client) and the resource authorizing entity (acting as 212 a Diameter server). A high-level picture of the resulting 213 architecture is shown in Figure 1. 215 +-------+---------+ 216 | Authorizing | 217 | Entity | 218 |(Diameter Server)| 219 +-------+---------+ 220 | 221 | 222 /\-----+-----/\ 223 //// \\\\ 224 || AAA Cloud || 225 | (Diameter application) | 226 || || 227 \\\\ //// 228 \-------+-----/ 229 | 230 +---+--+ +-----+----+ +---+--+ 231 | | | NE | | | Media 232 + NE +===+(Diameter +===+ NE +=============>> 233 | | | Client) | | | Flow 234 +------+ +----------+ +------+ 236 Figure 1: An Architecture supporting QoS-AAA 238 Figure 1 depicts network elements through which media flows need to 239 pass, a cloud of AAA servers, and an authorizing entity. Note that 240 there may be more than one router that needs to interact with the AAA 241 cloud along the path of a given application flow, although the figure 242 only depicts one for clarity. 244 In some deployment scenarios, QoS aware network elements may request 245 authorization through the AAA cloud based on an incoming QoS 246 reservation request. The network element will route the request to a 247 designated authorizing entity. The authorizing entity will return 248 the result of the authorization decision. In other deployment 249 scenarios, the authorization will be initiated upon dynamic 250 application state, so that the request must be authenticated and 251 authorized based on information from one or more application servers. 253 If defined properly, the interface between the routers and AAA cloud 254 would be identical in both cases. Routers are therefore insulated 255 from the details of particular applications and need not know that 256 application servers are involved at all. Also, the AAA cloud would 257 naturally encompass business relationships such as those between 258 network operators and third-party application providers, enabling 259 flexible intra- or inter-domain authorization, accounting, and 260 settlement. 262 3.1. Network element functional model 264 Figure 2 depicts a logical operational model of resource management 265 in a router. 267 +-----------------------------------------------------+ 268 | DIAMETER Client | 269 | Functionality | 270 | +---------------++---------------++---------------+ | 271 | | User || Authorization || Accounting | | 272 | | Authentication|| of QoS || for QoS | | 273 | +---------------+| Requests || Traffic | | 274 | +---------------++---------------+ | 275 +-----------------------------------------------------+ 276 ^ 277 v 278 +--------------+ +----------+ 279 |QoS Signaling | | Resource | 280 |Msg Processing|<<<<<>>>>>>>|Management| 281 +--------------+ +----------+ 282 . ^ | * ^ 283 | v . * ^ 284 +-------------+ * ^ 285 |Signaling msg| * ^ 286 | Processing | * V 287 +-------------+ * V 288 | | * V 289 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 290 . . * V 291 | | * ............................. 292 . . * . Traffic Control . 293 | | * . +---------+. 294 . . * . |Admission|. 295 | | * . | Control |. 296 +----------+ +------------+ . +---------+. 297 <-.-| Input | | Outgoing |-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-> 298 | Packet | | Interface | .+----------+ +---------+. 299 ===>|Processing|====| Selection |===.| Packet |====| Packet |.=> 300 | | |(Forwarding)| .|Classifier| Scheduler|. 301 +----------+ +------------+ .+----------+ +---------+. 302 ............................. 303 <.-.-> = signaling flow 304 =====> = data flow (sender --> receiver) 305 <<<>>> = control and configuration operations 306 ****** = routing table manipulation 308 Figure 2: Network element functional model 310 Processing of incoming QoS reservation requests includes three 311 actions: admission control, authorization and resource reservation. 313 The admission control function provides information for available 314 resources and determines whether there are enough resources to 315 fulfill the request. Authorization is performed by the Diameter 316 client function which involves contacting an authorization entity 317 through the AAA cloud shown in Section 3. If both checks are 318 successful, the authorized QoS parameters are set in the packet 319 classifier and the packet scheduler. Note that the parameters passed 320 to the Traffic Control function may be different from requested QoS 321 (depending on the authorization decision). Once the requested 322 resource is granted, the Resource Management function provides 323 accounting information to the Authorizing entity using the Diameter 324 client function. 326 3.2. Implications of endpoint QoS capabilities 328 3.2.1. Category of endpoint QoS capabilities 330 The QoS capabilities of endpoints are varied, which can be 331 categorized as follows: 332 o Category 1 endpoint: Has no QoS capability at both application and 333 network levels. This type of endpoint may set up a connection 334 through application signaling, but it is unable to specify any 335 resource/QoS requirements either through application signaling 336 e.g. SIP or through network signaling e.g. RSVP or NSIS (or does 337 not support network signaling at all). 338 o Category 2 endpoint: Only has QoS capability at the application 339 level. This type of endpoint is able to set up a connection 340 through application signaling with certain resource/QoS 341 requirements (e.g. application attributes), but it is unable to 342 specify any network level resource/QoS requirements (e.g., network 343 QoS class) through network signaling e.g., RSVP or NSIS (or does 344 not support network layer signaling at all). 345 o Category 3: endpoint: Has QoS capability at the network level. 346 This type of endpoint may set up a connection through application 347 signaling and translate service characteristics into network 348 resource/QoS requirements (e.g. network QoS class) locally, and 349 request the resources through network signaling e.g. RSVP or 350 NSIS. 352 3.2.2. Interaction modes between authorizing entity and network element 354 Different QoS mechanisms are employed in packet networks. Those QoS 355 mechanisms can be categorized into two schemes: IntServ and DiffServ. 356 In the IntServ scheme, network signaling e.g RSVP, NSIS, or link 357 specific signaling is commonly used to initiate a request from 358 endpoint for desired QoS resource of media flow. In the DiffServ 359 scheme, the QoS resources are provisioned based on some predefined 360 QoS service classes instead of endpoint initiated per flow based QoS 361 request. 363 It is obvious that the eligible QoS scheme is correlated to the 364 endpoint's capability in the context of QoS authorization. Since 365 category 1 and 2 endpoints cannot initiate the QoS resource requests 366 through the network signaling, the IntServ model is not applicable to 367 them in general. Depending on network technology and operator's 368 demand, a category 3 endpoint may either make use of the network 369 signaling for requesting the resource or not perform the request. 371 The diversity of QoS capabilities of endpoints and QoS schemes of 372 network technology leads to the distinction on the interaction mode 373 between QoS authorization system and underlying network elements. 374 When the IntServ scheme is employed by category 3 endpoint, the 375 authorization process is typically initiated by network element when 376 a trigger such as the network signaling is received from the 377 endpoint. In the DiffServ scheme, since the network element is 378 unable to request the resource authorization on its own initiative, 379 the authorization process is typically triggered upon either the 380 request of application servers or policies defined by the operator. 382 As a consequence, two interaction modes are needed in support of 383 different combinations of QoS schemes and endpoint's QoS 384 capabilities. Push mode and Pull mode. 386 o Push mode: The QoS authorization process is triggered by 387 application servers or local network conditions (e.g. time of day 388 on resource usage and QoS classes), and the authorization 389 decisions are installed by the authorzing entity to the network 390 element on its own initiative without explicit request. In order 391 to support the push mode, the authorizing entity (i.e. Diameter 392 server) should be able to initiate a Diameter authorization 393 session to communicate with the network element (i.e. Diameter 394 client) without any pre-established connection from the network 395 element. 396 o Pull mode: The QoS authorization process is triggered by the 397 network signaling received from end user equipments or by the 398 local event in the network element according to pre-configured 399 policies, and authorization decisions are produced upon the 400 request of the network element. In order to support the pull 401 mode, the network element (i.e. Diameter client) will initiate a 402 Diameter authorization session to communicate with authorizing 403 entity (i.e. Diameter server). 404 For category 1 and 2 endpoints, the Push mode is required, in 405 particular, category 1 endpoint requires network initiated push mode 406 and category 2 endpoint may use both them. For category 3 endpoint, 407 either push mode or pull mode is doable. 409 The Push mode is applicable to certain networks, for example, Cable 410 network, DSL, Ethernet, Diffserv enabled IP/MPLS as defined by other 411 SDOs e.g. ETSI TISPAN and ITU-T. The Pull mode is more appropriate 412 to IntServ enabled IP networks or certain wireless networks such as 413 GPRS networks as defined by 3GPP/PP2. Some networks e.g. WiMAX may 414 require both Push and Pull modes. 416 3.3. Authorization schemes 418 3.3.1. Authorization schemes for pull mode 420 Three basic authorization schemes for pull mode exist: one two-party 421 and two three-party schemes. The notation adopted here is in respect 422 to the entity that performs the QoS authorization. The 423 authentication of the QoS requesting entity might be done at the 424 network element as part of the QoS signaling protocol, or by an off- 425 path protocol run (on the application layer or for network access 426 authentication) or the authorizing entity might be contacted with 427 request for authentication and authorization of the QoS requesting 428 entity. From the Diameter QoS application's point of view these 429 schemes differ in type of information that need to be carried. Here 430 we focus on the 'Three party scheme' (Figure 3) and the Token-based 431 three party scheme' (Figure 4). With the 'Two party scheme' the QoS 432 resource requesting entity is authenticated by the Network Element 433 and the authorization decision is made either locally at the Network 434 Element itself or offloaded to a trusted entity (most likely within 435 the same administrative domain). In the former case no Diameter QoS 436 protocol interaction is required. 438 +--------------+ 439 | Entity | 440 | authorizing | <......+ 441 | resource | . 442 | request | . 443 +------------+-+ . 444 --^----------|-- . . 445 ///// | | \\\\\ . 446 // | | \\ . 447 | QoS | QoS AAA | QoS |. 448 | authz| protocol |authz |. 449 | req.| | res. |. 450 \\ | | // . 451 \\\\\ | | ///// . 452 QoS --|----------v-- . . 453 +-------------+ request +-+------------+ . 454 | Entity |----------------->| NE | . 455 | requesting | | performing | . 456 | resource |granted / rejected| QoS | <.....+ 457 | |<-----------------| reservation | financial 458 +-------------+ +--------------+ settlement 460 Figure 3: Three Party Scheme 462 With the 'Three party scheme' a QoS reservation request that arrives 463 at the Network Element is forwarded to the Authorizing Entity (e.g., 464 in the user's home network), where the authorization decision is 465 made. A business relationship, such as a roaming agreement, between 466 the visited network and the home network ensures that the visited 467 network is compensated for the resources consumed by the user via the 468 home network. 470 financial settlement 471 ...........................+ 472 Authorization V ------- . 473 Token Request +--------------+ / QoS AAA \ . 474 +-------------->| | / protocol \ . 475 | | Authorizing +--------------+ \ . 476 | | Entity | | | | . 477 | +------+ |<--+----+ | | . 478 | | +--------------+ |QoS | |QoS |. 479 | | |authz| |authz|. 480 | |Authorization |req.+| |res. |. 481 | |Token |Token| | |. 482 | | | | | . | . 483 | | \ | | . / . 484 | | \ | | / . 485 | | QoS request |-----V . . 486 +-------------+ + Authz. Token +--------+-----+ . 487 | Entity |----------------->| NE | . 488 | requesting | | performing | . 489 | resource |granted / rejected| QoS | <....+ 490 | |<-----------------| reservation | 491 +-------------+ +--------------+ 493 Figure 4: Token-based Three Party Scheme 495 The 'Token-based Three Party scheme' is applicable to environments 496 where a previous protocol interaction is used to request 497 authorization tokens to assist the authorization process at the 498 Network Element or the Authorizing Entity. 500 The QoS resource requesting entity may be involved in an application 501 layer protocol interaction, for example using SIP, with the 502 Authorizing Entity. As part of this interaction, authentication and 503 authorization at the application layer might take place. As a result 504 of a successful authorization decision, which might involve the 505 user's home AAA server, an authorization token is generated by the 506 Authorizing Entity (e.g., the SIP proxy and an entity trusted by the 507 SIP proxy) and returned to the end host for inclusion into the QoS 508 signaling protocol. The authorization token will be used by a 509 Network Element that receives the QoS signaling message to authorize 510 the QoS request. Alternatively, the Diameter QoS application will be 511 used to forward the authorization token to the user's home network. 512 The authorization token allows the authorization decision performed 513 at the application layer protocol run to be associated with a 514 corresponding QoS signaling session. Note that the authorization 515 token might either refer to established state concerning the 516 authorization decision or the token might itself carry the authorized 517 parameters (protected by a digital signature or a keyed message 518 digest to prevent tampering). In the latter case the authorization 519 token may contain several pieces of information pertaining to the 520 authorized application session, but at minimum it should contain: 521 o An identifier of the Authorizing Entity (for example, of an 522 application server) that issued the authorization token, 523 o An identifier referring to a specific application protocol session 524 for which the token was issued and 525 o A keyed message digest or digital signature protecting the content 526 of the authorization token. 528 A possible structure for the authorization token and the policy 529 element carrying it are proposed in context of RSVP [RFC3520]. 531 In the scenario mentioned above, where the QoS resource requesting 532 entity is involved in an application layer protocol interaction with 533 the Authorizing entity, it may be worthwhile to consider a token less 534 binding mechanism also. The application layer protocol interaction 535 may have indicated the transport port numbers at the QoS resource 536 requesting entity where it might receive media streams, for example 537 in SIP/SDP signalling these port numbers are advertised. The QoS 538 resource requesting entity may also use these port numbers in some IP 539 filter indications to the NE performing QoS reservation so that it 540 may properly tunnel the inbound packets. The NE performing QoS 541 reservation will forward the QoS resource requesting entity's IP 542 address and the IP filter indications to the Authorizing entity in 543 the QoS authz. request. The Authorizing entity will use the QoS 544 resource requesting entity's IP address and the port numbers in the 545 IP filter indication, which will match the port numbers advertised in 546 the earlier application layer protocol interaction, to identify the 547 right piece of policy information to be sent to the NE performing the 548 QoS reservation in the QoS authz. response. 550 3.3.2. Authorization schemes for push mode 552 The push mode can be further divided into two types: endpoint 553 initiated and network initiated. In the former case, the 554 authorization process is triggered by application server upon 555 explicit QoS request from endpoints through application signaling, 556 e.g. SIP; in the latter case, the authorization process is triggered 557 by application server without explicit QoS request from endpoint. 559 In the endpoint initiated scheme, the QoS resource requesting entity 560 (i.e. endpoint) determines the required application level QoS and 561 sends the QoS request through application signaling message, the 562 Application Server will extract application level QoS information and 563 trigger the authorization process to Authorizing entity. In the 564 network initiated scheme, the Authorizing entity and/or Application 565 sever should derive and determine the QoS requirement according to 566 application attribute, subscription and endpoint's capability when 567 the endpoint does not explicitly indicate the QoS attributes. The 568 authorizing entity makes authorization decision based on application 569 level QoS information, network policies, end user subscription and 570 network resource availability etc., and installs the decision to 571 network element directly. 573 financial settlement 574 ...........................+ 575 Application V ------- . 576 signaling msg +--------------+ / QoS AAA \ . 577 +-------------->| | / protocol \ . 578 | | Authorizing +--------------+ \ . 579 | | Entity | | | | . 580 | + |<--+----+ | | . 581 | +--------------+ |QoS | |QoS |. 582 | install| |install 583 | |rsp. | |req. |. 584 | | | | |. 585 | | | | . | . 586 | \ | | . / . 587 | \ | | / . 588 V |-----V . . 589 +-------------+ +--------+-----+ . 590 | Entity | | NE | . 591 | requesting | | performing | . 592 | resource |QoS rsrc granted | QoS | <....+ 593 | |<-----------------| reservation | 594 +-------------+ +--------------+ 596 Figure 5: Authorization Scheme for Push Mode 598 3.4. QoS Authorization Requirements 600 A QoS authorization application must meet a number of requirements 601 applicable to a diverse set of networking environments and services. 602 It should be compliant with different deployment scenarios with 603 specific QoS signaling models and security issues. Satisfying the 604 requirements listed below while interworking with QoS signaling 605 protocols, a Diameter QoS application should accommodate the 606 capabilities of the QoS signaling protocols rather than introducing 607 functional requirements on them. A list of requirements for a QoS 608 authorization application is provided here: 610 Inter-domain support 612 In particular, users may roam outside their home network, leading 613 to a situation where the network element and authorizing entity 614 are in different administrative domains. 616 Identity-based Routing 618 The QoS AAA protocol MUST route AAA requests to the Authorizing 619 Entity, based on the provided identity of the QoS requesting 620 entity or the identity of the Authorizing entity encoded in the 621 provided authorization token. 623 Flexible Authentication Support 625 The QoS AAA protocol MUST support a variety of different 626 authentication protocols for verification of authentication 627 information present in QoS signaling messages. The support for 628 these protocols MAY be provided indirectly by tying the signaling 629 communication for QoS to a previous authentication protocol 630 exchange (e.g., using network access authentication). 632 Making an Authorization Decision 634 The QoS AAA protocol MUST exchange sufficient information between 635 the authorizing entity and the enforcing entity (and vice versa) 636 to compute an authorization decision and to execute this decision. 638 Triggering an Authorization Process 640 The QoS AAA protocol MUST allow periodic and event triggered 641 execution of the authorization process, originated at the 642 enforcing entity or even at the authorizing entity. 644 Associating QoS Reservations and Application State 646 The QoS AAA protocol MUST carry information sufficient for an 647 application server to identify the appropriate application session 648 and associate it with a particular QoS reservation. 650 Dynamic Authorization 652 It MUST be possible for the QoS AAA protocol to push updates 653 towards the network element(s) from authorizing entities. 655 Bearer Gating 657 The QoS AAA protocol MUST allow the authorizing entity to gate 658 (i.e., enable/disable) authorized application flows based on e.g., 659 application state transitions. 661 Accounting Records 663 The QoS AAA protocol MUST define QoS accounting records containing 664 duration, volume (byte count) usage information and description of 665 the QoS attributes (e.g., bandwidth, delay, loss rate) that were 666 supported for the flow. 668 Sending Accounting Records 670 The network element SHOULD send accounting records for a 671 particular QoS reservation state to the authorizing entity, which 672 plays the role of an accounting entity. 674 Failure Notification 676 The QoS AAA protocol MUST allow the network element to report 677 failures, such as loss of connectivity due to movement of a mobile 678 node or other reasons for packet loss, to the authorizing entity. 680 Accounting Correlation 682 The QoS AAA protocol MUST support the exchange of sufficient 683 information to allow for correlation between accounting records 684 generated by the network elements and accounting records generated 685 by an application server. 687 Interaction with other AAA Applications 689 Interaction with other AAA applications such as Diameter Network 690 Access (NASREQ) application [RFC4005] is required for exchange of 691 authorization, authentication and accounting information. 693 In deployment scenarios, where authentication of the QoS reservation 694 requesting entity (e.g., the user) is done by means outside the 695 Diameter QoS application protocol interaction the Authorizing Entity 696 is contacted only with a request for QoS authorization. 697 Authentication might have taken place already via the interaction 698 with the Diameter NASREQ application or as part of the QoS signaling 699 protocol (e.g., Transport Layer Security (TLS) handshake in the 700 General Internet Signaling Transport (GIST) protocol, see 701 [I-D.ietf-nsis-ntlp]). 703 Authentication of the QoS reservation requesting entity to the 704 Authorizing Entity is necessary if a particular Diameter QoS 705 application protocol run cannot be related (or if there is no 706 intention to relate it) to a prior authentication. In this case the 707 Authorizing Entity MUST authenticate the QoS reservation requesting 708 entity in order to authorize the QoS request as part of the Diameter 709 QoS protocol interaction. 711 The document refers to three types of sessions that need to be 712 properly correlated. 714 QoS signaling session 716 The time period during which a QoS signaling protocol establishes, 717 maintains and deletes a QoS reservation state at the QoS network 718 element is referred as QoS signaling session. Different QoS 719 signaling protocols use different ways to identify QoS signaling 720 sessions. The same applies to different usage environments. 721 Currently, this document supports three types of QoS session 722 identifiers, namely a signaling session id (e.g., the Session 723 Identifier used by the NSIS protocol suite), a flow id (e.g., 724 identifier assigned by an application to a certain flow as used in 725 the 3GPP) and a flow description based on the IP parameters of the 726 flow's end points. The details can be found in Section 7.4. 728 Diameter authorization session 730 The time period, for which a Diameter server authorizes a 731 requested service (i.e., QoS resource reservation) is referred to 732 as a Diameter authorization session. It is identified by a 733 Session-Id included in all Diameter messages used for management 734 of the authorized service (initial authorization, re- 735 authorization, termination), see [RFC3588]. 737 Application layer session 739 The application layer session identifies the duration of an 740 application layer service which requires provision of certain QoS. 741 An application layer session identifier is provided by the QoS 742 requesting entity in the QoS signaling messages, for example as 743 part of the authorization token. In general, the application 744 session identifier is opaque to the QoS aware network elements. 745 It is included in the authorization request message sent to the 746 Authorizing entity and helps it to correlate the QoS authorization 747 request to the application session state information. 749 Correlating these sessions is done at each of the three involved 750 entities: The QoS requesting entity correlates the application with 751 the QoS signaling sessions. The QoS network element correlates the 752 QoS signaling session with the Diameter authorization sessions. The 753 Authorizing entity SHOULD bind the information about the three 754 sessions together. Note that in certain scenarios not all of the 755 sessions are present. For example, the application session might not 756 be visible to QoS signaling protocol directly if there is no binding 757 between the application session and the QoS requesting entity using 758 the QoS signaling protocol. 760 4. Diameter QoS Authorization Session Establishment and Management 762 4.1. Parties involved 764 Authorization models supported by this application include three 765 parties: 766 o Resource requesting entity 767 o Network Elements (Diameter QoS clients) 768 o Authorizing Entity (Diameter QoS server) 769 Note that the QoS resource requesting entity is only indirectly 770 involved in the message exchange. This entity provides the trigger 771 to initiate the Diameter QoS protocol interaction by transmitting QoS 772 signaling messages. The Diameter QoS application is only executed 773 between the Network Element (i.e., Diameter QoS client) and the 774 Authorizing Entity (i.e., Diameter QoS server). 776 The QoS resource requesting entity may communicate with the 777 Authorizing Entity using application layer signaling for negotiation 778 of service parameters. As part of this application layer protocol 779 interaction, for example using SIP, authentication and authorization 780 might take place. This message exchange is, however, outside the 781 scope of this document. The protocol communication between the the 782 QoS resource requesting entity and the QoS Network Element might be 783 accomplished using the NSIS protocol suite, RSVP or a link layer 784 signaling protocol. A description of these protocols is also outside 785 the scope of this document and a tight coupling with these protocols 786 is not desirable since this applications aims to be generic. 788 4.2. Diameter QoS Authorization Session Establishment 790 Figure 7 shows the protocol interaction between a resource requesting 791 entity, a Network Element and the Authorizing Entity. 793 A request for a QoS reservation received by a Network Element 794 initiates a Diameter QoS authorization session. The Network Element 795 generates a QoS-Authorization-Request (QAR) message in which it maps 796 required objects from the QoS signaling message to Diameter payload 797 objects. 799 +----------------------------------+-------------------------------+ 800 | QoS specific Input Data | Diameter QoS AVPs | 801 +----------------------------------+-------------------------------+ 802 | Authorizing entity ID (e.g., | Destination-Host | 803 | taken from authorization token | Destination-Realm | 804 | or from Network Access ID (NAI) | | 805 | [RFC2486] of the QoS requesting | | 806 | entity) | | 807 +----------------------------------+-------------------------------+ 808 | Authorization Token | QoS-Authz-Data | 809 | Credentials of | User-Name | 810 | the QoS requesting entity | | 811 +----------------------------------+-------------------------------+ 812 | QoS parameters | QoS-Resources | 813 +----------------------------------+-------------------------------+ 815 The Authorizing Entity's identity, information about the application 816 session and/or identity and credentials of the QoS resource 817 requesting entity, requested QoS parameters, signaling session 818 identifier and/or QoS enabled data flows identifiers MAY be 819 encapsulated into respective Diameter AVPs and included into the 820 Diameter message sent to the Authorizing Entity. The QAR is sent to 821 a Diameter server that can either be the home server of the QoS 822 requesting entity or an application server. 824 Authorization processing starts at the Diameter QoS server when it 825 receives the QAR. Based on the information in the QoS- 826 Authentication-Data, User-Name and QoS-Resources AVPs the server 827 determines the authorized QoS resources and flow state (enabled/ 828 disabled) from locally available information (e.g., policy 829 information that may be previously established as part of an 830 application layer signaling exchange, or the user's subscription 831 profile). The authorization decision is then reflected in the 832 response returned to the Diameter client with the QoS-Authorization- 833 Answer message (QAA). 835 Authorizing 836 End-Host Network Element Entity 837 requesting QoS ( Diameter ( Diameter 838 QoS Client) QoS Server) 839 | | | 840 +---QoS-Reserve---->| | 841 | +- - - - - QAR - - - - - >| 842 | |(QoS-Resources,Cost, | 843 | | QoS-Auth-Data,User-ID)| 844 | | +--------+--------------+ 845 | | | Authorize request | 846 | | | Keep session data | 847 | | |/Authz-time,Session-Id/| 848 | | +--------+--------------+ 849 | |< - - - - QAA - - - - - -+ 850 | |(Result-Code,CC-Time,Cost| 851 | |QoS-Resources,Authz-time)| 852 | +-------+---------+ 853 | |Install QoS state| 854 | | + | 855 | | Authz. session | 856 | | /Authz-time, | QoS Responder 857 | | CC-Time,Cost/ | Node 858 | +-------+---------+ | 859 | +----------QoS-Reserve---....--->| 860 | | | 861 | |<---------QoS-Response--....----| 862 |<--QoS-Response----+ | 863 | | | 864 |=====================Data Flow==============....===>| 865 | | 866 | +- - - - - ACR - - - - - >| 867 | |(START,QoS-Resources,Cost| 868 | |CC-Time,Acc-Multisess-id)| 869 | | +--------+--------------+ 870 | | | Report for successful | 871 | | | QoS reservation | 872 | | |Update of reserved QoS | 873 | | | resources | 874 | | +--------+--------------+ 875 | |< - - - - ACA - - - - - -+ 876 | | | 878 Figure 7: Initial QoS Request Authorization 880 The Authorizing Entity keeps authorization session state and SHOULD 881 save additional information for management of the session (e.g., Acc- 882 Multi-Session-Id, Signaling-Session-Id, authentication data) as part 883 of the session state information. A Signaling-session-Id (if 884 present) SHOULD be used together with the generated Acc-Multi- 885 Session-Id AVP (see Section 7.3) for binding the authorization and 886 the accounting session information in case of end host mobility 887 (i.e., to correlate the Diameter sessions that are initiated for the 888 same signaling session from different QoS NE). 890 The final result of the authorization request is provided in the 891 Result-Code AVP of the QAA message sent by the Authorizing Entity. 892 In case of successful authorization (i.e., Result-Code = 893 DIAMETER_LIMITED_SUCCESS, (see Section 7.1)), information about the 894 authorized QoS resources and the status of the authorized flow 895 (enabled/disabled) is provided in the QoS-Resources AVP of the QAA 896 message. The QoS information provided via the QAA is installed by 897 the QoS Traffic Control function of the Network Element (see 898 Figure 2). The value DIAMETER_LIMITED_SUCCESS indicates that the 899 Authorizing entity expects confirmation via an accounting message for 900 successful QoS resource reservation and for final reserved QoS 901 resources (see bellow). 903 One important piece of information returned from the Authorizing 904 Entity is the authorization lifetime (carried inside the QAA). The 905 authorization lifetime allows the Network Element to determine how 906 long the authorization decision is valid for this particular QoS 907 reservation. A number of factors may influence the authorized 908 session duration, such as the user's subscription plan or currently 909 available credits at the user's account (see Section 5). The 910 authorization duration is time-based as specified in [RFC3588]. For 911 an extension of the authorization period, a new QoS-Authorization- 912 Request/Answer message exchange SHOULD be initiated. Further aspects 913 of QoS authorization session maintenance is discussed in Section 4.3, 914 Section 4.5 and Section 5. 916 The indication of a successful QoS reservation and activation of the 917 data flow, is provided by the transmission of an Accounting Request 918 (ACR) message, which reports the parameters of the established QoS 919 state: reserved resources, duration of the reservation, 920 identification of the QoS enabled flow/QoS signaling session and 921 accounting parameters. The Diameter QoS server acknowledges the 922 reserved QoS resources with the Accounting Answer (ACA) message where 923 the Result-Code is set to 'DIAMETER_SUCCESS'. Note that the reserved 924 QoS resources reported in the ACR message MAY be different than those 925 initially authorized with the QAA message, due to the QoS signaling 926 specific behavior (e.g., receiver-initiated reservations with One- 927 Path-With-Advertisements) or specific process of QoS negotiation 928 along the data path. 930 4.3. QoS authorization session re-authorization 932 Client and server-side initiated re-authorizations are considered in 933 the design of the Diameter QoS application. Whether the re- 934 authorization events are transparent for the resource requesting 935 entity or result in specific actions in the QoS signaling protocol is 936 outside the scope of the Diameter QoS application. It is directly 937 dependent on the capabilities of the QoS signaling protocol. 939 In addition, there are a number of options for policy rules according 940 to which the NE (AAA client) contacts the Authorizing Entity for re- 941 authorization. These rules depend on the semantics and contents of 942 the QAA message sent by the Authorizing Entity: 944 a. The QAA message contains the authorized parameters of the flow 945 and its QoS and sets their limits (presumably upper). With these 946 parameters the Authorizing Entity specifies the services that the 947 NE can provide and will be financially compensated for. 948 Therefore, any change or request for change of the parameters of 949 the flow and its QoS that do not conform to the authorized limits 950 requires contacting the Authorizing Entity for authorization. 951 b. The QAA message contains authorized parameters of the flow and 952 its QoS. The rules that determine whether parameters' changes 953 require re-authorization are agreed out of band, based on a 954 Service Level Agreement (SLA) between the domains of the NE and 955 the Authorizing Entity. 956 c. The QAA message contains the authorized parameters of the flow 957 and its QoS. Any change or request for change of these 958 parameters requires contacting the Authorizing entity for re- 959 authorization. 960 d. In addition to the authorized parameters of the flow and its QoS, 961 the QAA message contains policy rules that determine the NEs 962 actions in case of change or request for change in authorized 963 parameters. 965 Provided options are not exhaustive. Elaborating on any of the 966 listed approaches is deployment /solution specific and is not 967 considered in the current document. 969 4.3.1. Client-Side Initiated Re-Authorization 971 The Authorizing Entity provides the duration of the authorization 972 session as part of the QoS-Authorization-Answer message (QAA). At 973 any time before expiration of this period, a new QoS-Authorization- 974 Request message (QAR) MAY be sent to the Authorizing Entity. The 975 transmission of the QAR MAY be triggered when the Network Element 976 receives a QoS signaling message that requires modification of the 977 authorized parameters of an ongoing QoS session, when authorization 978 lifetime expires or by an accounting event, see Section 5 and 979 Figure 8). 981 Authorizing 982 End-Host Network Element Entity 983 requesting QoS ( Diameter ( Diameter 984 QoS Client) QoS Server) 985 | | | 986 |=====================Data Flow==========================> 987 | | | 988 | +-------+----------+ | 989 | |Authz-time/CC-Time| | 990 | | expires | | 991 | +-------+----------+ | 992 | +- - - - - QAR - - - - - >| 993 | |(QoS-Resources,Cost, | 994 | | QoS-Authz-Data,User-ID)| 995 | +--------+--------------+ 996 NOTE: | | Authorize request | 997 Re-authorization | | Update session data | 998 is transparent to | |/Authz-time,Session-Id/| 999 the End-Host | +--------+--------------+ 1000 |< - - - - QAA - - - - - -+ 1001 | |(Result-Code,CC-Time,Cost| 1002 | |QoS-Resources,Authz-time)| 1003 | +-------+---------+ | 1004 | |Update QoS state | | 1005 | | + | | 1006 | | Authz. session | | 1007 | | /Authz-time, | | 1008 | | CC-Time,Cost/ | | 1009 | +-------+---------+ | 1010 | | | 1011 | +- - - - - ACR - - - - - >| 1012 | |(INTRM,QoS-Resources,Cost| 1013 | |CC-Time,Acc-Multisess-id)| 1014 | | +--------+--------------+ 1015 | | |Update of QoS resources| 1016 | | |/CC-Time,Cost/ used | 1017 | | +--------+--------------+ 1018 | |< - - - - ACA - - - - - -+ 1019 | | | 1020 |=====================Data Flow==========================> 1021 | | 1023 Figure 8: QoS request re-authorization 1025 4.3.2. Server-Side Initiated Re-Authorization 1027 The Authorizing Entity MAY optionally initiate a QoS re-authorization 1028 by issuing a Re-Auth-Request message (RAR) as defined in the Diameter 1029 base protocol [RFC3588]. A Network Element client that receives such 1030 a RAR message with Session-Id matching a currently active QoS session 1031 acknowledges the request by sending the Re-Auth-Answer (RAA) message 1032 and MUST initiate a QoS reservation re-authorization by sending a 1033 QoS-Authorization-Request (QAR) message towards the Authorizing 1034 entity. 1036 4.4. Server-Side Initiated QoS Parameter Provisioning 1038 In certain deployment scenarios (mostly applicable for local QoS 1039 provision) an active control over the QoS resource and QoS enabled 1040 data flows from the network side is required. Therefore, the 1041 Authorizing Entity is enabled to update installed QoS parameters and 1042 flow state at the Network Element by sending a QoS-Install Request 1043 message (QIR). Network Elements MUST apply the updates and respond 1044 with an QoS-Install Answer message (QIA). This functionality, for 1045 example, allows the update of already authorized flow status of an 1046 established QoS reservation due to a change at the application layer 1047 session (see Figure 9). 1049 Authorizing 1050 End-Host Network Element Entity 1051 requesting QoS ( Diameter ( Diameter 1052 QoS Client) QoS Server) 1053 | | | 1054 +===================+=Data Flow==========================> 1055 | | +--------+--------------+ 1056 | | |Data flow preemption | 1057 | | +--------+--------------+ 1058 | |< - - - - QIR - - - - - -+ 1059 | |(QoS-Resources[QoS-Flow- | 1060 | | -State=CLOSE]) | 1061 | +-------+---------+ | 1062 | |Update QoS state | | 1063 | | + | | 1064 | | Authz. session | | 1065 | |/QoS-Flow-State= | | 1066 | | CLOSE/ | | 1067 | +-------+---------+ | 1068 +====Data Flow=====>X | 1069 | +- - - - - QIA - - - - - >| 1070 | | (Result-Code) | 1071 Figure 9: Server-Side Initiated QoS Parameter Provisioning 1073 The Authorizing Entity MAY initiate a QoS authorization session 1074 establishment and QoS reservation state installation (prior to a 1075 request from a Network Element). This function requires that the 1076 Authorizing Entity has knowledge of specific information identifying 1077 the Network Element that should be contacted and the data flow for 1078 which the QoS reservation should be established.(mostly applicable 1079 for local scenarios) 1081 4.5. Session Termination 1083 4.5.1. Client-Side Initiated Session Termination 1085 The authorization session for an installed QoS reservation state MAY 1086 be terminated by the Diameter client by sending a Session- 1087 Termination-Request message (STR) to the Diameter server. This is a 1088 Diameter base protocol function and it is defined in [RFC3588]. 1089 Session termination can be caused by a QoS signaling messaging 1090 requesting deletion of the existing QoS reservation state or it can 1091 be caused as a result of a soft-state expiration of the QoS 1092 reservation state. After a successful termination of the 1093 authorization session, final accounting messages MUST be exchanged 1094 (see Figure 10). It should be noted that the two sessions 1095 (authorization and accounting) have independent management by the 1096 Diameter base protocol, which allows for finalizing the accounting 1097 session after the end of the authorization session. 1099 Authorizing 1100 End-Host Network Element Entity 1101 requesting QoS ( Diameter ( Diameter 1102 QoS Client) QoS Server) 1103 | | | 1104 |==Data Flow==>X /Stop of the data flow/ | 1105 | | | 1106 +---QoS-Reserve---->| | 1107 | (Delete QoS +- - - - - STR - - - - - >| 1108 | reservation) | +--------+--------------+ 1109 | | | Remove authorization | 1110 |<--QoS-Response----+ | session state | 1111 | | +--------+--------------+ 1112 |< - - - - STA - - - - - -+ 1113 +-------+--------+ | 1114 |Delete QoS state| 1115 | Report final | 1116 | accounting data| QoS Responder 1117 +-------+--------+ Node 1118 +----------QoS-Reserve-----....--->| 1119 | (Delete QoS | 1120 | reservation) 1121 | 1122 +- - - - - ACR - - - - - >| 1123 |(FINAL,QoS-Resources,Cost| 1124 |CC-Time,Acc-Multisess-id)| 1125 | +--------+--------------+ 1126 | | Report for successful | 1127 | | end of QoS session | 1128 | +--------+--------------+ 1129 |< - - - - ACA - - - - - -+ 1130 | 1131 | QoS Responder 1132 | Node 1133 |<---------QoS-Response----....----+ 1134 | | 1136 Figure 10: Client-Side Initiated Session Termination 1138 4.5.2. Server-Side Initiated Session Termination 1140 At anytime during a session the Authorizing Entity MAY send an Abort- 1141 Session-Request message (ASR) to the Network Element. This is a 1142 Diameter base protocol function and it is defined in [RFC3588]. 1143 Possible reasons for initiating the ASR message to the Network 1144 Element are insufficient credits or session termination at the 1145 application layer. The ASR message results in termination of the 1146 authorized session, release of the reserved resources at the Network 1147 Element and transmission of an appropriate QoS signaling message 1148 indicating a notification to other Network Elements aware of the 1149 signaling session. A final accounting message exchange MUST be 1150 triggered as a result of this ASR message exchange (see Figure 11). 1152 Authorizing 1153 End-Host Network Element Entity 1154 requesting QoS ( Diameter ( Diameter 1155 QoS Client) QoS Server) 1156 | | | 1157 |=====================Data Flow==========================> 1158 | | 1159 | |< - - - - ASR - - - - - -+ 1160 | | | 1161 |====Data Flow=====>X | QoS Responder 1162 | | | Node 1163 |<--QoS-Notify------+----------QoS-Reserve-----....--->| 1164 | | (Delete QoS | | 1165 | reservation) | 1166 +-------+--------+ | 1167 |Delete QoS state| | 1168 | Report final | | 1169 | accounting data| | 1170 +-------+--------+ | 1171 +- - - - - ASA - - - - - >| 1172 | +--------+--------------+ 1173 | | Remove authorization | 1174 | | session state | 1175 | +--------+--------------+ 1176 +- - - - - ACR - - - - - >| 1177 |(FINAL,QoS-Resources,Cost| 1178 |CC-Time,Acc-Multisess-id)| 1179 | +--------+--------------+ 1180 | | Report for successful | 1181 | | end of QoS session | 1182 | +--------+--------------+ 1183 |< - - - - ACA - - - - - -+ 1184 | QoS Responder 1185 | Node 1186 |<---------QoS-Response----....----+ 1187 | | 1189 Figure 11: Server-Side Initiated Session Termination 1191 5. Accounting 1193 The Diameter QoS application provides accounting for usage of 1194 reserved QoS resources. Diameter QoS accounting has built-in support 1195 for online, duration based accounting. This accounting is based on 1196 the notion that the Diameter QoS clients are in the best position to 1197 determine the cost of those resources. 1199 In the Diameter QoS application, the router MAY send a Cost- 1200 Information AVP (see [RFC4006]) in the QAR. If the Cost-Information 1201 AVP includes a Cost-Unit AVP (see [RFC4006]) then the Cost-Unit 1202 SHOULD be "minute". The Cost-Information AVPs represent the cost to 1203 allocate the resources requested in the QoS-Resources AVP included in 1204 the same QAR message. The QAR MAY optionally contain a Tariff-Time- 1205 Change AVP (see [RFC4006]) which is the time at which the cost will 1206 change, a second Cost-Information AVP, which is the cost of the 1207 reserved resources after the tariff time change, and a second Tariff- 1208 Time-Change, which is the time at which the tariff would change 1209 again. Either all three or none of these AVPs MUST be present in the 1210 QAR. 1212 The Resource Authorizing Entity returns a CC-Time AVP (see [RFC4006]) 1213 in the QAA message which is the total authorized gate-on time for the 1214 service. If the QAR included two Tariff-Time-Change AVPs, the 1215 current time plus the CC-Time AVP returned in the QAA MUST NOT exceed 1216 the second Tariff-Time-Change AVP from the QAR. Based on information 1217 in the Cost-Information AVPs, the Resource Authorizing Entity can use 1218 the CC-Time AVP to guarantee that the total cost of the session will 1219 not exceed a certain threshold, which allows, for example, support of 1220 prepaid users. 1222 Each ACR message contains a triplet of QoS-Resources AVP, Cost- 1223 Information AVP, and CC-Time AVP. This represents the total time 1224 consumed at the given cost for the given resources. Note that an ACR 1225 message MUST be sent separately for each interval defined by the 1226 Tariff-Time-Change AVPs and the expiration of the CC-Time returned in 1227 the QAA (see Figure 8). 1229 The Network Element starts an accounting session by sending an 1230 Accounting-Request message (ACR) after successful QoS reservation and 1231 activation of the data flow (see Figure 7). After every successful 1232 re-authorization procedure the Network element MUST initiate an 1233 interim accounting message exchange (see Figure 8). After successful 1234 session termination the Network element MUST initiate a final 1235 exchange of accounting messages for terminating of the accounting 1236 session and reporting final records for the usage of the QoS 1237 resources reserved (see Figure 10). 1239 6. Diameter QoS Authorization Application Messages 1241 The Diameter QoS Application requires the definition of new mandatory 1242 AVPs and Command-codes (see Section 3 of [RFC3588]). Four new 1243 Diameter messages are defined along with Command-Codes whose values 1244 MUST be supported by all Diameter implementations that conform to 1245 this specification. 1247 Command-Name Abbrev. Code Reference 1248 QoS-Authz-Request QAR [TBD] Section 6.1 1249 QoS-Authz-Answer QAA [TBD] Section 6.2 1250 QoS-Install-Request QIR [TBD] Section 6.3 1251 QoS-Install-Answer QIA [TBD] Section 6.4 1253 In addition, the following Diameter Base protocol messages are used 1254 in the Diameter QoS application: 1256 Command-Name Abbrev. Code Reference 1257 Accounting-Request ACR 271 RFC 3588 1258 Accounting-Request ACR 271 RFC 3588 1259 Accounting-Answer ACA 271 RFC 3588 1260 Re-Auth-Request RAR 258 RFC 3588 1261 Re-Auth-Answer RAA 258 RFC 3588 1262 Abort-Session-Request ASR 274 RFC 3588 1263 Abort-Session-Answer ASA 274 RFC 3588 1264 Session-Term-Request STR 275 RFC 3588 1265 Session-Term-Answer STA 275 RFC 3588 1267 Diameter nodes conforming to this specification MAY advertise support 1268 by including the value of TBD in the Auth-Application-Id or the Acct- 1269 Application-Id AVP of the Capabilities-Exchange-Request and 1270 Capabilities-Exchange-Answer commands, see [RFC3588]. 1272 The value of TBD MUST be used as the Application-Id in all QAR/QAA 1273 and QIR/QIA commands. 1275 The value of TBD MUST be used as the Application-Id in all ACR/ACA 1276 commands, because this application defines new, mandatory AVPs for 1277 accounting. 1279 The value of zero (0) SHOULD be used as the Application-Id in all 1280 STR/STA, ASR/ASA, and RAR/RAA commands, because these commands are 1281 defined in the Diameter base protocol and no additional mandatory 1282 AVPs for those commands are defined in this document. 1284 6.1. QoS-Authorization Request (QAR) 1286 The QoS-Authorization-Request message (QAR) indicated by the Command- 1287 Code field (see Section 3 of [RFC3588]) set to TBD and 'R' bit set in 1288 the Command Flags field is used by Network elements to request 1289 quality of service related resource authorization for a given flow. 1291 The QAR message MUST carry information for signaling session 1292 identification, Authorizing Entity identification, information about 1293 the requested QoS, and the identity of the QoS requesting entity. In 1294 addition, depending on the deployment scenario, an authorization 1295 token and credentials of the QoS requesting entity SHOULD be 1296 included. 1298 The message format, presented in ABNF form [RFC2234], is defined as 1299 follows: 1301 ::= < Diameter Header: XXX, REQ, PXY > 1302 < Session-Id > 1303 { Auth-Application-Id } 1304 { Origin-Host } 1305 { Origin-Realm } 1306 { Destination-Realm } 1307 { Auth-Request-Type } 1308 [ Destination-Host ] 1309 [ User-Name ] 1310 * [ QoS-Resources ] 1311 [ QoS-Authz-Data ] 1312 [ Cost-Information ] 1313 [ Acc-Multisession-Id ] 1314 [ Bound-Auth-Session-Id ] 1315 * [ AVP ] 1317 6.2. QoS-Authorization Answer (QAA) 1319 The QoS-Authorization-Answer message (QAA), indicated by the Command- 1320 Code field set to TBD and 'R' bit cleared in the Command Flags field 1321 is sent in response to the QoS-Authorization-Request message (QAR). 1322 If the QoS authorization request is successfully authorized, the 1323 response will include the AVPs to allow authorization of the QoS 1324 resources as well as accounting and transport plane gating 1325 information. 1327 The message format is defined as follows: 1329 ::= < Diameter Header: XXX, PXY > 1330 < Session-Id > 1331 { Auth-Application-Id } 1332 { Auth-Request-Type } 1333 { Result-Code } 1334 { Origin-Host } 1335 { Origin-Realm } 1336 * [ QoS-Resources ] 1337 [ CC-Time ] 1338 [ Acc-Multisession-Id ] 1339 [ Session-Timeout ] 1340 [ Authz-Session-Lifetime ] 1341 [ Authz-Grace-Period ] 1342 * [ AVP ] 1344 6.3. QoS-Install Request (QIR) 1346 The QoS-Install Request message (QIR), indicated by the Command-Code 1347 field set to TDB and 'R' bit set in the Command Flags field is used 1348 by Authorizing entity to install or update the QoS parameters and the 1349 flow state of an authorized flow at the transport plane element. 1351 The message MUST carry information for signaling session 1352 identification or identification of the flow to which the provided 1353 QoS rules apply, identity of the transport plane element, description 1354 of provided QoS parameters, flow state and duration of the provided 1355 authorization. 1357 The message format is defined as follows: 1359 ::= < Diameter Header: XXX, REQ, PXY > 1360 < Session-Id > 1361 { Auth-Application-Id } 1362 { Origin-Host } 1363 { Origin-Realm } 1364 { Destination-Realm } 1365 { Auth-Request-Type } 1366 [ Destination-Host ] 1367 * [ QoS-Resources ] 1368 [ Session-Timeout ] 1369 [ Authz-Session-Lifetime ] 1370 [ Authz-Grace-Period ] 1371 [ Authz-Session-Volume ] 1372 * [ AVP ] 1374 6.4. QoS-Install Answer (QIA) 1376 The QoS-Install Answer message (QIA), indicated by the Command-Code 1377 field set to TBD and 'R' bit cleared in the Command Flags field is 1378 sent in response to the QoS-Install Request message (QIR) for 1379 confirmation of the result of the installation of the provided QoS 1380 reservation instructions. 1382 The message format is defined as follows: 1384 ::= < Diameter Header: XXX, PXY > 1385 < Session-Id > 1386 { Auth-Application-Id } 1387 { Origin-Host } 1388 { Origin-Realm } 1389 { Result-Code } 1390 * [ QoS-Resources ] 1391 * [ AVP ] 1393 6.5. Accounting Request (ACR) 1395 The Accounting Request message (ACR), indicated by the Command-Code 1396 field set to 271 and 'R' bit set in the Command Flags field is used 1397 by Network Element to report parameters of the authorized and 1398 established QoS reservation. 1400 The message MUST carry accounting information authorized QoS 1401 resources and its usage, e.g., QoS-Resources, CC-Time, CC-Cost, Acc- 1402 Multi-Session-Id. 1404 The message format is defined as follows: 1406 ::= < Diameter Header: XXX, REQ, PXY > 1407 < Session-Id > 1408 { Acct-Application-Id } 1409 { Destination-Realm } 1410 [ Destination-Host ] 1411 [ Accounting-Record-Type ] 1412 [ Accounting-Record-Number ] 1413 * [ QoS-Resources ] 1414 [ Cost-Information ] 1415 [ CC-Time ] 1416 [ Acc-Multi-Session-Id ] 1417 * [ AVP ] 1419 6.6. Accounting Answer (ACA) 1421 The Accounting Answer message (ACA), indicated by the Command-Code 1422 field set to 271 and 'R' bit cleared in the Command Flags field is 1423 sent in response to the Accounting Request message (ACR) as an 1424 acknowledgment of the ACR message and MAY carry additional management 1425 information for the accounting session, e.g. Acc-Interim-Interval 1426 AVP. 1428 The message format is defined as follows: 1430 ::= < Diameter Header: XXX, PXY > 1431 < Session-Id > 1432 { Acct-Application-Id } 1433 [ Result-Code ] 1434 [ Accounting-Record-Type ] 1435 [ Accounting-Record-Number ] 1436 [ Acc-Multi-Session-Id ] 1437 * [ AVP ] 1439 7. Diameter QoS Authorization Application AVPs 1441 Each of the AVPs identified in the QoS-Authorization-Request/Answer 1442 and QoS-Install-Request/Answer messages and the assignment of their 1443 value(s) is given in this section. 1445 7.1. Diameter Base Protocol AVPs 1447 The Diameter QoS application uses a number of session management 1448 AVPs, defined in the Base Protocol ([RFC3588]). 1450 Attribute Name AVP Code Reference [RFC3588] 1451 Origin-Host 264 Section 6.3 1452 Origin-Realm 296 Section 6.4 1453 Destination-Host 293 Section 6.5 1454 Destination-Realm 283 Section 6.6 1455 Auth-Application-Id 258 Section 6.8 1456 Result-Code 268 Section 7.1 1457 Auth-Request-Type 274 Section 8.7 1458 Session-Id 263 Section 8.8 1459 Authz-Lifetime 291 Section 8.9 1460 Authz-Grace-Period 276 Section 8.10 1461 Session-Timeout 27 Section 8.13 1462 User-Name 1 Section 8.14 1464 The Auth-Application-Id AVP (AVP Code 258) is assigned by IANA to 1465 Diameter applications. The value of the Auth-Application-Id for the 1466 Diameter QoS application is TBD. 1468 7.2. Credit Control Application AVPs 1470 The Diameter QoS application provides accounting for usage of 1471 reserved QoS resources. Diameter QoS accounting has built-in support 1472 for online, duration based accounting. For this purpose it re-uses a 1473 number of AVPs defined in Diameter Credit Control application. 1474 [RFC4006]. 1476 Attribute Name AVP Code Reference [RFC4006] 1477 Cost-Information AVP 423 Section 8.7 1478 Unit-Value AVP 445 Section 8.8 1479 Currency-Code AVP 425 Section 8.11 1480 Cost-Unit AVP 424 Section 8.12 1481 CC-Time AVP 420 Section 8.21 1482 Tariff-Time-Change AVP 451 Section 6.20 1484 Usage of the listed AVPs is described in Section 5 1485 Diameter QoS application is designed to independently provide credit 1486 control over the controlled QoS resources. However, deployment 1487 scenarios, where Diameter QoS application is collocated with Diameter 1488 Credit Control application, are not excluded. In such scenarios the 1489 credit control over the QoS resources might be managed by the Credit 1490 control application. Possible interworking approach might be a usage 1491 of Credit-Control AVP (AVP Code 426) with a newly defined value. It 1492 will indicate to the Diameter QoS entities that the credit control 1493 over the QoS resources would be handled in separate session by Credit 1494 Control application. An active cooperation of both applications 1495 would be required but it is not elaborated further in this document. 1497 7.3. Accounting AVPs 1499 The Diameter QoS application uses Diameter Accounting and accounting 1500 AVPs as defined in Section 9 of [RFC3588]. Additional description of 1501 the usage of some of them in the QoS authorization context is 1502 provided: 1504 Attribute Name AVP Code Reference [RFC3588] 1505 Acct-Application-Id 259 Section 6.9 1506 Accounting-Record-Type 480 Section 9.8.1 1507 Accounting-Interim-Interval 85 Section 9.8.2 1508 Accounting-Record-Number 485 Section 9.8.3 1509 Accounting-Realtime-Required 483 Section 9.8.7 1510 Acc-Multi-Session-ID 50 Section 9.8.5 1512 The following AVPs need further explanation: 1514 Acct-Application-Id AVP 1516 The Acct-Application-Id AVP (AVP Code 259)is assigned by IANA to 1517 Diameter applications. The value of the Acct-Application-Id for 1518 the Diameter QoS application is TBD (TBD). 1520 Acc-Multisession-ID 1522 Acc-Multi-Session-ID AVP (AVP Code 50) SHOULD be used to link 1523 multiple accounting sessions together, allowing the correlation of 1524 accounting information. This AVP MAY be returned by the Diameter 1525 server in a QoS-Authorization-Answer message (QAA), and MUST be 1526 used in all accounting messages for the given session. 1528 7.4. Diameter QoS Application Defined AVPs 1530 This document reuses the AVPs defined in Section 4 of 1531 [I-D.ietf-dime-qos-attributes]. 1533 This section lists the AVPs that are used by this specifispecific to 1534 the Diameter QoS application. 1536 Additionally, the followig new AVPs are defined: 1537 Bound-Auth-Session-Id and the QoS-Authz-Data AVP 1539 The following table describes the Diameter AVPs newly defined in this 1540 document for usage with the QoS Application, their AVP code values, 1541 types, possible flag values, and whether the AVP may be encrypted. 1543 +-------------------+ 1544 | AVP Flag rules | 1545 +----------------------------------------------|----+---+----+-----+ 1546 | AVP Section | | |SHLD| MUST| 1547 | Attribute Name Code Defined Data Type |MUST|MAY| NOT| NOT| 1548 +----------------------------------------------+----+---+----+-----+ 1549 |QoS-Authz-Data TBD 7.4 Grouped | M | P | | V | 1550 |Bound-Auth-Session-Id TBD 7.4 UTF8String | M | P | | V | 1551 +----------------------------------------------+----+---+----+-----+ 1552 |M - Mandatory bit. An AVP with "M" bit set and its value MUST be | 1553 | supported and recognized by a Diameter entity in order the | 1554 | message, which carries this AVP, to be accepted. | 1555 |P - Indicates the need for encryption for end-to-end security. | 1556 |V - Vendor specific bit that indicates whether the AVP belongs to | 1557 | a address space. | 1558 +------------------------------------------------------------------+ 1560 QoS-Authz-Data 1562 The QoS-Authz-Data AVP (AVP Code TBD) is of type OctetString. It 1563 is a container that carries application session or user specific 1564 data that has to be supplied to the Authorizing entity as input to 1565 the computation of the authorization decision. 1567 Bound-Authentication-Session-Id 1569 The Bound-Authentication-Session AVP (AVP Code TBD) is of type 1570 UTF8String. It carries the id of the Diameter authentication 1571 session that is used for the network access authentication (NASREQ 1572 authentication session). It is used to tie the QoS authorization 1573 request to a prior authentication of the end host done by a co- 1574 located application for network access authentication (Diameter 1575 NASREQ) at the QoS NE. 1577 8. Examples 1579 This section presents an example of the interaction between the 1580 application layer signaling and the QoS signaling along the data 1581 path. The application layer signaling is, in this example, provided 1582 using SIP. Signaling for a QoS resource reservation is done using 1583 the QoS NSLP. The authorization of the QoS reservation request is 1584 done by the Diameter QoS application (DQA). 1586 End-Host SIP Server Correspondent 1587 requesting QoS (DQA Server) Node 1589 | | | 1590 ..|....Application layer SIP signaling.......|..............|.. 1591 . | Invite (SDP) | | . 1592 . +.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-> | . 1593 . | 100 Trying | | . 1594 . <.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-+ Invite (SDP)| . 1595 . | +-.-.-.....-.-.> . 1596 . | | 180 SDP' | . 1597 . | <-.-.-.....-.-.+ . 1598 . | +--------+--------+ | . 1599 . | |Authorize session| | . 1600 . | | parameters | | . 1601 . | 180 (Session parameters) +--------+--------+ | . 1602 . <.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-+ | . 1603 ..|..........................................|... ..........|.. 1604 | | | 1605 | +------------+ | | 1606 | | NE | | | 1607 | |(DQA Client)| | | 1608 | +------+-----+ | | 1609 | | | | 1610 |QoS NSLP Reserve | | | 1611 +------------------> QAR | | 1612 | (POLICY_DATA>v +- - - - -<>- - - -> | 1613 | QSPEC) v >===>(Destination-Host, | | 1614 | v >=======>QoS-Authz-Data ++------------+ | 1615 | >===========>QoS-Resources, |Authorize | | 1616 | |Cost-Info) |QoS resources| | 1617 | | ++------------+ | 1618 | | QAA | | 1619 | <- - - - -<>- - - -+ | 1620 | |(Result-Code, | | 1621 | |QoS-Resources, | | 1622 | |CC-Time, | | 1623 | |Authz-Lifetime) | | 1624 | +---------+--------+ | | 1625 | |Install QoS state1| | | 1626 | |+ Authz. session | | | 1627 | +---------+--------+ | | 1628 | |QoS NSLP Reserve | 1629 | +---------------..............---------> 1630 | | | 1631 | | QoS NSLP Response| 1632 |QoS NSLP Response <---------------..............---------+ 1633 <------------------+ | 1634 | | QoS NSLP Query| 1635 |QoS NSLP Query <---------------..............---------+ 1636 <------------------+ | 1637 |QoS NSLP Reserve | | 1638 +------------------> QAR | | 1639 | +- - - - -<>- - - -> | 1640 | | +---+---------+ | 1641 | | |Authorize | | 1642 | | |QoS resources| | 1643 | | QAA +---+---------+ | 1644 | <- - - - -<>- - - -+ | 1645 | +---------+--------+ | | 1646 | |Install QoS state2| | 1647 | |+ Authz. session | | 1648 | +---------+--------+ | 1649 | | QoS NSLP Reserve | 1650 | +---------------..............---------> 1651 | | QoS NSLP Response| 1652 |QoS NSLP Response <---------------..............---------+ 1653 <------------------+ | 1654 | | | 1655 /------------------+--Data Flow---------------------------\ 1656 \------------------+--------------------------------------/ 1657 | | | 1659 .-.-.-.-. SIP signaling 1660 --------- QoS NSLP signaling 1661 - - - - - Diameter QoS Application messages 1662 ========= Mapping of objects between QoS and AAA protocol 1664 Figure 24: Token-based QoS Authorization Example 1666 The communication starts with SIP signaling between the two end 1667 points and the SIP server for negotiation and authorization of the 1668 requested service and its parameters (see Figure 24). As a part of 1669 the process, the SIP server verifies whether the user at Host A is 1670 authorized to use the requested service (and potentially the ability 1671 to be charged for the service usage). Negotiated session parameters 1672 are provided to the end host. 1674 Subsequently, Host A initiates a QoS signaling message towards Host 1675 B. It sends a QoS NSLP Reserve message, in which it includes 1676 description of the required QoS (QSPEC object) and authorization data 1677 for negotiated service session (part of the POLICY_DATA object). 1678 Authorization data includes, as a minimum, the identity of the 1679 authorizing entity (e.g., the SIP server) and an identifier of the 1680 application service session for which QoS resources are requested. 1682 A QoS NSLP Reserve message is intercepted and processed by the first 1683 QoS aware Network Element. The NE uses the Diameter QoS application 1684 to request authorization for the received QoS reservation request. 1685 The identity of the Authorizing Entity (in this case the SIP server 1686 that is co-located with a Diameter server) is put into the 1687 Destination-Host AVP, any additional session authorization data is 1688 encapsulated into the QoS-Authz-Data AVP and the description of the 1689 QoS resources is included into QoS-Resources AVP. In addition, the 1690 NE rates the requested QoS resources and announces the charging rate 1691 into the Cost-Information AVP. These AVPs are included into a QoS 1692 Authorization Request message, which is sent to the Authorizing 1693 entity. 1695 A Diameter QAR message will be routed through the AAA network to the 1696 Authorizing Entity. The Authorizing Entity verifies the requested 1697 QoS against the QoS resources negotiated for the service session and 1698 replies with QoS-Authorization answer (QAA) message. It carries the 1699 authorization result (Result-Code AVP) and the description of the 1700 authorized QoS parameters (QoS-Resources AVP), as well as duration of 1701 the authorization session (Authorization-Lifetime AVP) and duration 1702 of the time (CC-Time) for which the end-user should be charged with 1703 the rate announced in the QAR message. The NE interacts with the 1704 traffic control function and installs the authorized QoS resources 1705 and forwards the QoS NSLP Reserve message further along the data 1706 path. 1708 Note that the example above shows a sender-initiated reservation from 1709 the End-Host towards the corresponding node and a receiver-initiated 1710 reservation from the correspondent node towards the End-Host. 1712 9. IANA Considerations 1714 TBD 1716 10. Security Considerations 1718 This document describes a mechanism for performing authorization of a 1719 QoS reservation at a third party entity. Therefore, it is necessary 1720 that the QoS signaling application to carry sufficient information 1721 that should be forwarded to the backend AAA server. This 1722 functionality is particularly useful in roaming environments where 1723 the authorization decision is most likely provided at an entity where 1724 the user can be authorized, such as in the home realm. 1726 QoS signaling application MAY re-use the authenticated identities 1727 used for the establishment of the secured transport channel for the 1728 signaling messages, e.g., TLS or IPsec between the end host and the 1729 policy aware QoS NE. In addition, a collocation of the QoS NE with, 1730 for example, the Diameter NASREQ application (see [RFC4005]) may 1731 allow the QoS authorization to be based on the authenticated identity 1732 used during the network access authentication protocol run. If a co- 1733 located deployment is not desired then special security protection is 1734 required to ensure that arbitrary nodes cannot reuse a previous 1735 authentication exchange to perform an authorization decision. 1737 Additionally, QoS authorization might be based on the usage of 1738 authorization tokens that are generated by the Authorizing Entity and 1739 provided to the end host via application layer signaling. 1741 The impact of the existence of different authorization models is 1742 (with respect to this Diameter QoS application) the ability to carry 1743 different authentication and authorization information. 1745 11. Acknowledgements 1747 The authors would like to thank John Loughney and Allison Mankin for 1748 their input to this document. In September 2005 Robert Hancock, 1749 Jukka Manner, Cornelia Kappler, Xiaoming Fu, Georgios Karagiannis and 1750 Elwyn Davies provided a detailed review. Robert also provided us 1751 with good feedback earlier in 2005. Jerry Ash provided us review 1752 comments late 2005/early 2006. Rajith R provided some inputs to the 1753 document early 2007 1755 [Editor's Note: Acknowledgements need to be updated.] 1757 12. Contributors 1759 The authors would like to thank Tseno Tsenov (tseno.tsenov@gmail.com) 1760 and Frank Alfano (falfano@lucent.com) for starting the Diameter 1761 Quality of Service work within the IETF, for your significant draft 1762 contributions and for being the driving force for the first few draft 1763 versions. 1765 [Editor's Note: A bit of history needs to be included here.] 1767 13. Open Issues 1769 Open issues related to this draft are listed at the issue tracker 1770 available at: http://www.tschofenig.com:8080/diameter-qos/ 1772 14. References 1774 14.1. Normative References 1776 [I-D.ietf-dime-qos-attributes] 1777 Korhonen, J., "Quality of Service Attributes for Diameter 1778 and RADIUS", draft-ietf-dime-qos-attributes-00 (work in 1779 progress), July 2007. 1781 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 1782 Requirement Levels", BCP 14, RFC 2119, March 1997. 1784 [RFC2234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax 1785 Specifications: ABNF", RFC 2234, November 1997. 1787 [RFC3588] Calhoun, P., Loughney, J., Guttman, E., Zorn, G., and J. 1788 Arkko, "Diameter Base Protocol", RFC 3588, September 2003. 1790 [RFC4005] Calhoun, P., Zorn, G., Spence, D., and D. Mitton, 1791 "Diameter Network Access Server Application", RFC 4005, 1792 August 2005. 1794 [RFC4006] Hakala, H., Mattila, L., Koskinen, J-P., Stura, M., and J. 1795 Loughney, "Diameter Credit-Control Application", RFC 4006, 1796 August 2005. 1798 14.2. Informative References 1800 [I-D.ietf-nsis-ntlp] 1801 Schulzrinne, H. and R. Hancock, "GIST: General Internet 1802 Signalling Transport", draft-ietf-nsis-ntlp-13 (work in 1803 progress), April 2007. 1805 [I-D.ietf-nsis-qos-nslp] 1806 Manner, J., "NSLP for Quality-of-Service Signaling", 1807 draft-ietf-nsis-qos-nslp-14 (work in progress), June 2007. 1809 [RFC2210] Wroclawski, J., "The Use of RSVP with IETF Integrated 1810 Services", RFC 2210, September 1997. 1812 [RFC2486] Aboba, B. and M. Beadles, "The Network Access Identifier", 1813 RFC 2486, January 1999. 1815 [RFC2749] Herzog, S., Boyle, J., Cohen, R., Durham, D., Rajan, R., 1816 and A. Sastry, "COPS usage for RSVP", RFC 2749, 1817 January 2000. 1819 [RFC2753] Yavatkar, R., Pendarakis, D., and R. Guerin, "A Framework 1820 for Policy-based Admission Control", RFC 2753, 1821 January 2000. 1823 [RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson, 1824 "Remote Authentication Dial In User Service (RADIUS)", 1825 RFC 2865, June 2000. 1827 [RFC3313] Marshall, W., "Private Session Initiation Protocol (SIP) 1828 Extensions for Media Authorization", RFC 3313, 1829 January 2003. 1831 [RFC3520] Hamer, L-N., Gage, B., Kosinski, B., and H. Shieh, 1832 "Session Authorization Policy Element", RFC 3520, 1833 April 2003. 1835 [RFC3521] Hamer, L-N., Gage, B., and H. Shieh, "Framework for 1836 Session Set-up with Media Authorization", RFC 3521, 1837 April 2003. 1839 [RFC4027] Josefsson, S., "Domain Name System Media Types", RFC 4027, 1840 April 2005. 1842 [RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session 1843 Description Protocol", RFC 4566, July 2006. 1845 Authors' Addresses 1847 Glen Zorn (editor) 1848 Cisco Systems 1849 2901 Third Avenue, Suite 600 1850 SEA1/5/ 1851 Seattle, WA 98121 1852 USA 1854 Phone: +1 (425) 344 8113 1855 Email: gwz@cisco.com 1857 Peter J. McCann 1858 Motorola Labs 1859 1301 E. Algonquin Rd 1860 Schaumburg, IL 60196 1861 USA 1863 Phone: +1 847 576 3440 1864 Email: pete.mccann@motorola.com 1866 Hannes Tschofenig 1867 Nokia Siemens Networks 1868 Otto-Hahn-Ring 6 1869 Munich, Bavaria 81739 1870 Germany 1872 Email: Hannes.Tschofenig@nsn.com 1873 URI: http://www.tschofenig.com 1875 Tina Tsou 1876 Huawei 1877 Shenzhen, 1878 P.R.C 1880 Email: tena@huawei.com 1881 Avri Doria 1882 Lulea University of Technology 1883 Arbetsvetenskap 1884 Lulea, SE-97187 1885 Sweden 1887 Email: avri@ltu.se 1889 Dong Sun 1890 Bell Labs/Alcatel-Lucent 1891 101 Crawfords Corner Rd 1892 Holmdel, NJ 07733 1893 USA 1895 Email: dongsun@alcatel-lucent.com 1897 Full Copyright Statement 1899 Copyright (C) The IETF Trust (2007). 1901 This document is subject to the rights, licenses and restrictions 1902 contained in BCP 78, and except as set forth therein, the authors 1903 retain all their rights. 1905 This document and the information contained herein are provided on an 1906 "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS 1907 OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND 1908 THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS 1909 OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF 1910 THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED 1911 WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 1913 Intellectual Property 1915 The IETF takes no position regarding the validity or scope of any 1916 Intellectual Property Rights or other rights that might be claimed to 1917 pertain to the implementation or use of the technology described in 1918 this document or the extent to which any license under such rights 1919 might or might not be available; nor does it represent that it has 1920 made any independent effort to identify any such rights. 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