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Checking references for intended status: Informational ---------------------------------------------------------------------------- -- Obsolete informational reference (is this intentional?): RFC 6347 (Obsoleted by RFC 9147) -- Obsolete informational reference (is this intentional?): RFC 6830 (Obsoleted by RFC 9300, RFC 9301) Summary: 0 errors (**), 0 flaws (~~), 1 warning (==), 3 comments (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Network Working Group M. Boucadair 3 Internet-Draft C. Jacquenet 4 Intended status: Informational Orange 5 Expires: December 4, 2016 D. Zhang 6 Huawei Technologies 7 P. Georgatsos 8 CERTH 9 June 2, 2016 11 Connectivity Provisioning Negotiation Protocol (CPNP) 12 draft-boucadair-connectivity-provisioning-protocol-12 14 Abstract 16 This document specifies the Connectivity Provisioning Negotiation 17 Protocol (CPNP) which is used for dynamic negotiation of service 18 parameters. 20 CPNP is a generic protocol that can be used for various negotiation 21 purposes that include (but are not necessarily limited to) 22 connectivity provisioning services, storage facilities, Content 23 Delivery Networks footprint, etc. The protocol can be extended with 24 new Information Elements. 26 Requirements Language 28 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 29 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 30 document are to be interpreted as described in RFC 2119 [RFC2119]. 32 Status of This Memo 34 This Internet-Draft is submitted in full conformance with the 35 provisions of BCP 78 and BCP 79. 37 Internet-Drafts are working documents of the Internet Engineering 38 Task Force (IETF). Note that other groups may also distribute 39 working documents as Internet-Drafts. The list of current Internet- 40 Drafts is at http://datatracker.ietf.org/drafts/current/. 42 Internet-Drafts are draft documents valid for a maximum of six months 43 and may be updated, replaced, or obsoleted by other documents at any 44 time. It is inappropriate to use Internet-Drafts as reference 45 material or to cite them other than as "work in progress." 47 This Internet-Draft will expire on December 4, 2016. 49 Copyright Notice 51 Copyright (c) 2016 IETF Trust and the persons identified as the 52 document authors. All rights reserved. 54 This document is subject to BCP 78 and the IETF Trust's Legal 55 Provisions Relating to IETF Documents 56 (http://trustee.ietf.org/license-info) in effect on the date of 57 publication of this document. Please review these documents 58 carefully, as they describe your rights and restrictions with respect 59 to this document. Code Components extracted from this document must 60 include Simplified BSD License text as described in Section 4.e of 61 the Trust Legal Provisions and are provided without warranty as 62 described in the Simplified BSD License. 64 Table of Contents 66 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 67 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 68 3. CPNP Functional Elements . . . . . . . . . . . . . . . . . . 6 69 4. Order Processing Models . . . . . . . . . . . . . . . . . . . 6 70 5. Sample Use Cases . . . . . . . . . . . . . . . . . . . . . . 8 71 6. CPNP Deployment Models . . . . . . . . . . . . . . . . . . . 10 72 7. CPNP Negotiation Model . . . . . . . . . . . . . . . . . . . 10 73 8. Protocol Overview . . . . . . . . . . . . . . . . . . . . . . 13 74 8.1. Client/Server Communication . . . . . . . . . . . . . . . 13 75 8.2. Server Discovery . . . . . . . . . . . . . . . . . . . . 13 76 8.3. Policy Configuration on the CPNP Server . . . . . . . . . 13 77 8.4. CPNP Session . . . . . . . . . . . . . . . . . . . . . . 15 78 8.5. Extended CPNP Session . . . . . . . . . . . . . . . . . . 15 79 8.6. CPNP Transaction . . . . . . . . . . . . . . . . . . . . 16 80 8.7. CPNP Timers . . . . . . . . . . . . . . . . . . . . . . . 16 81 8.8. CPNP Operations . . . . . . . . . . . . . . . . . . . . . 16 82 8.9. Connectivity Provisioning Documents . . . . . . . . . . . 18 83 8.10. Child Provisioning Quotation Orders . . . . . . . . . . . 19 84 8.11. Negotiations with Multiple CPNP Servers . . . . . . . . . 20 85 8.12. State Management . . . . . . . . . . . . . . . . . . . . 21 86 8.12.1. On the Client Side . . . . . . . . . . . . . . . . . 21 87 8.12.2. On the Server Side . . . . . . . . . . . . . . . . . 23 88 9. CPNP Objects . . . . . . . . . . . . . . . . . . . . . . . . 25 89 9.1. Attributes . . . . . . . . . . . . . . . . . . . . . . . 25 90 9.1.1. CUSTOMER_AGREEMENT_IDENTIFIER . . . . . . . . . . . . 25 91 9.1.2. PROVIDER_AGREEMENT_IDENTIFIER . . . . . . . . . . . . 25 92 9.1.3. TRANSACTION_ID . . . . . . . . . . . . . . . . . . . 26 93 9.1.4. SEQUENCE_NUMBER . . . . . . . . . . . . . . . . . . . 26 94 9.1.5. NONCE . . . . . . . . . . . . . . . . . . . . . . . . 26 95 9.1.6. EXPECTED_RESPONSE_TIME . . . . . . . . . . . . . . . 26 96 9.1.7. EXPECTED_OFFER_TIME . . . . . . . . . . . . . . . . . 26 97 9.1.8. VALIDITY_OFFER_TIME . . . . . . . . . . . . . . . . . 27 98 9.1.9. CONNECTIVITY_PROVISIONING_DOCUMENT . . . . . . . . . 27 99 9.1.10. Information Elements . . . . . . . . . . . . . . . . 27 100 9.2. Operation Messages . . . . . . . . . . . . . . . . . . . 29 101 9.2.1. QUOTATION . . . . . . . . . . . . . . . . . . . . . . 29 102 9.2.2. PROCESSING . . . . . . . . . . . . . . . . . . . . . 29 103 9.2.3. OFFER . . . . . . . . . . . . . . . . . . . . . . . . 31 104 9.2.4. ACCEPT . . . . . . . . . . . . . . . . . . . . . . . 31 105 9.2.5. DECLINE . . . . . . . . . . . . . . . . . . . . . . . 32 106 9.2.6. ACK . . . . . . . . . . . . . . . . . . . . . . . . . 32 107 9.2.7. CANCEL . . . . . . . . . . . . . . . . . . . . . . . 33 108 9.2.8. WITHDRAW . . . . . . . . . . . . . . . . . . . . . . 34 109 9.2.9. UPDATE . . . . . . . . . . . . . . . . . . . . . . . 34 110 9.2.10. FAIL . . . . . . . . . . . . . . . . . . . . . . . . 36 111 10. Message Validation . . . . . . . . . . . . . . . . . . . . . 37 112 10.1. On the Client Side . . . . . . . . . . . . . . . . . . . 37 113 10.2. On the Server Side . . . . . . . . . . . . . . . . . . . 38 114 11. Theory of Operation . . . . . . . . . . . . . . . . . . . . . 38 115 11.1. Client Behavior . . . . . . . . . . . . . . . . . . . . 38 116 11.1.1. Order Negotiation Cycle . . . . . . . . . . . . . . 38 117 11.1.2. Order Withdrawal Cycle . . . . . . . . . . . . . . . 40 118 11.1.3. Order Update Cycle . . . . . . . . . . . . . . . . . 40 119 11.2. Server Behavior . . . . . . . . . . . . . . . . . . . . 41 120 11.2.1. Order Processing . . . . . . . . . . . . . . . . . . 41 121 11.2.2. Order Withdrawal . . . . . . . . . . . . . . . . . . 42 122 11.2.3. Order Update . . . . . . . . . . . . . . . . . . . . 42 123 11.3. Sequence Numbers . . . . . . . . . . . . . . . . . . . . 42 124 11.4. Message Re-Transmission . . . . . . . . . . . . . . . . 43 125 12. Operational Guidelines . . . . . . . . . . . . . . . . . . . 43 126 12.1. Logging on the CPNP Server . . . . . . . . . . . . . . . 43 127 12.2. Business Guidelines & Objectives . . . . . . . . . . . . 43 128 13. Security Considerations . . . . . . . . . . . . . . . . . . . 44 129 14. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 45 130 15. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 45 131 16. References . . . . . . . . . . . . . . . . . . . . . . . . . 45 132 16.1. Normative References . . . . . . . . . . . . . . . . . . 45 133 16.2. Informative References . . . . . . . . . . . . . . . . . 46 134 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 47 136 1. Introduction 138 This document defines the Connectivity Provisioning Negotiation 139 Protocol (CPNP) that is meant to dynamically exchange and negotiate 140 connectivity provisioning parameters, and other service-specific 141 parameters, between a Customer and a Provider. CPNP is a tool that 142 introduces automation in the service negotiation and activation 143 procedures, thus fostering the overall service provisioning process. 145 CPNP can be seen as a component of the dynamic negotiation meta- 146 domain described in Section 3.4 of [RFC7149]. 148 CPNP is a generic protocol that can be used for other negotiation 149 purposes than connectivity provisioning. For example, CPNP can be 150 used to request extra storage resources, to extend the footprint of a 151 CDN (Content Delivery Networks), to enable additional features from a 152 cloud Provider, etc. CPNP can be extended with new Information 153 Elements (IEs). 155 [RFC7297] describes a Connectivity Provisioning Profile (CPP) 156 template to capture connectivity requirements to be met by a 157 transport infrastructure for the delivery of various services such as 158 Voice over IP (VoIP), IPTV, and Virtual Private Network (VPN) 159 services [RFC4026]. The CPP document defines the set of IP transfer 160 parameters that reflect the guarantees that can be provided by the 161 underlying transport network together with reachability scope and 162 capacity needs. CPNP uses the CPP template to encode connectivity 163 provisioning clauses. 165 As a reminder, several proposals have been made in the past by the 166 (research) community (e.g., COPS-SLS, Service Negotiation Protocol 167 (SrNP), Dynamic Service Negotiation Protocol (DSNP), Resource 168 Negotiation and Pricing Protocol (RNAP), Service Negotiation and 169 Acquisition Protocol (SNAP), etc.). It is out of the scope of this 170 document to elaborate on the differences between CPNP and the 171 aforementioned proposals. 173 This document is organized as follows: 175 o Section 3 defines the functional elements involved in CPNP 176 exchanges. 177 o Section 4 introduces several order processing models and precises 178 those that are targeted by CPNP. 179 o Section 5 enumerates a non-exhaustive list of use cases that could 180 benefit from CPNP. 181 o Section 5 discusses CPNP deployment models. 182 o Section 7 presents the CPNP negotiation model. 183 o Section 8 provides an overview of the protocol. 184 o Section 9 specifies the CPNP objects. 185 o Section 10 describes the CPNP message validation procedure. 186 o Section 11 specifies the behavior of the involved CPNP functional 187 elements. 188 o Section 12 discusses relevant operational guidelines. 189 o Section 13 discusses protocol security aspects. 191 2. Terminology 193 This document makes use of the following terms: 195 Customer: Is a business role which denotes an entity that is 196 involved in the definition and the possible negotiation of a 197 contract, including a Connectivity Provisioning Agreement, with a 198 Provider. A connectivity provisioning contract is captured in a 199 dedicated CPP template-based document, which specifies (among 200 other information): the sites to be connected, border nodes, 201 outsourced operations (e.g., routing, force via points). 203 The right to invoke the subscribed service may be delegated by the 204 Customer to third-party End Users, or brokering services. 206 A Customer can be a Service Provider, an application owner, an 207 enterprise, a user, etc. 209 Network Provider (or Provider): Owns and administers one or many 210 transport domain(s) (typically Autonomous System (AS)) composed of 211 IP switching and transmission resources (e.g., routing, switching, 212 forwarding, etc.). Network Providers are responsible for ensuring 213 connectivity services (e.g., offering global or restricted 214 reachability at specific rates). Offered connectivity services 215 may not necessarily be restricted to IP. 217 The policies to be enforced by the connectivity service delivery 218 components can be derived from the technology-specific clauses 219 that might be included in contracts agreed with the Customers. If 220 no such clauses are included in the agreement, the mapping between 221 the connectivity requirements and the underlying technology- 222 specific policies to be enforced is deployment-specific. 224 Quotation Order: Denotes a request made by the Customer to the 225 Provider that includes a set of requirements. The Customer may 226 express its service-specific requirements by assigning (fixed or 227 loosely defined) values to the information items included in the 228 commonly understood template (e.g., CPP template) describing the 229 offered service. These requirements constitute the parameters to 230 be mutually agreed upon. 232 Offer: Refers to a response made by the Provider to a Customer 's 233 quotation order as to the extent at which the Provider may satisfy 234 the order at the time of its receipt. Offers reflect the 235 capability of the Provider in accommodating received Customer 236 orders beyond monolithic 'yes/no' answers. 238 An offer may fully or partially meet the requirements of the 239 corresponding order. In the latter case, it may include 240 alternative suggestions which the Customer may take into account 241 by issuing a new order. 243 Agreement: Refers to an order placed by the Customer and accepted by 244 the Provider. It signals the successful conclusion of a 245 negotiation cycle. 247 3. CPNP Functional Elements 249 The following functional elements are defined: 251 CPNP client (or client): Denotes a software instance that sends 252 CPNP requests and receives CPNP responses. The current operations 253 that can be performed by a CPNP client are listed below: 255 1. Create a quotation order (Section 11.1.1). 257 2. Cancel an ongoing quotation order under negotiation 258 (Section 11.1.1). 260 3. Accept an offer made by a server (Section 11.1.1). 262 4. Withdraw an agreement (Section 11.1.2). 264 5. Update an agreement (Section 11.1.3). 266 CPNP server (or server): Denotes a software instance that receives 267 CPNP requests and sends back CPNP responses accordingly. The CPNP 268 server is responsible for the following operations: 270 1. Process a quotation order (Section 11.2.1). 272 2. Make an offer (Section 11.2.1). 274 3. Cancel an ongoing quotation order (Section 11.2.2). 276 4. Process an order withdrawal (Section 11.2.3). 278 4. Order Processing Models 280 For preparing their service orders, the Customers may need to be 281 aware of the offered services. The Providers therefore should first 282 proceed with the announcement of the services that they can provide. 283 The service announcement process may take place at designated global 284 or Provider-specific service markets, or through explicit 285 interactions with the Providers. The details of this process are 286 outside the scope of a negotiation protocol. 288 With or without such service announcement mechanisms in place, the 289 following order processing models can be distinguished: 291 The following order processing models can be distinguished: 293 Frozen model: The Customer cannot actually negotiate the parameters 294 of the service(s) offered by a Provider. After consulting the 295 Provider's service portfolio, the Customer selects the service 296 offer he/she wants to subscribe and places an order to the 297 Provider. Order handling is quite simple on the Provider side 298 because the service is not customized as per Customer's 299 requirements, but rather pre-designed to target a group of 300 customers having similar requirements (i.e., these customers share 301 the same Customer Provisioning Profile). 303 Negotiation-based model: Unlike the frozen model, the Customer 304 documents his/her requirements in a request for a quotation, which 305 is then sent to one or several Providers. Solicited Providers 306 check whether they can address these requirements or not, and get 307 back to the Customer accordingly, possibly with an offer that may 308 not exactly match customer's requirements (e.g., a 100 Mbps 309 connection cannot be provisioned given the amount of available 310 resources, but an 80 Mbps connection can be provided). A 311 negotiation between the Customer and the Provider(s) then follows 312 to the end of reaching an agreement. 314 Both frozen and negotiation-based models require the existence of 315 appropriate service templates like a CPP template and their 316 instantiation for expressing specific offerings from Providers and 317 service requirements from Customers, respectively. CPNP can be used 318 in either model for automating the required Customer-Provider 319 interactions. Since the frozen model can be seen as a special case 320 of the negotiation-based model, not only 'yes/no' answers but also 321 counter offers may be issued by the Provider in response to Customer 322 orders, this document focuses on the negotiation-based model. 324 Order processing management on the Network Provider's side is usually 325 connected with the following functional blocks: 327 o Network Provisioning (including Order Activation, Network 328 Planning, etc.) 329 o Authentication, Authorization and Accounting (AAA) 330 o Network and service management (performance verification, 331 complaint analysis, etc.) 333 o Sales-related functional blocks (e.g., billing, invoice 334 validation, etc.) 335 o Network Impact Analysis 337 CPNP does not assume any specific knowledge about these functional 338 blocks, drawing an explicit line between protocol operation and the 339 logic for handling connectivity provisioning requests. Evidently 340 order handling logic is subject to the information manipulated by 341 these blocks. For example, the resources that can be allocated to 342 accommodate Customer's requirements may depend on network 343 availability estimates as calculated by the planning functions and 344 related policies as well as on the number of orders to be processed 345 simultaneously over a given period of time. 347 This document does not elaborate on how Customers are identified and 348 subsequently managed by the Provider's Information System. 350 5. Sample Use Cases 352 A non-exhaustive list of CPNP use cases is provided below: 354 1. [RFC4176] introduces the L3VPN Service Order Management 355 functional block which is responsible for managing the requests 356 initiated by the Customers and tracks the status of the 357 completion of the related operations. CPNP can be used between 358 the Customer and the Provider to negotiate L3VPN service 359 parameters. 361 A CPNP server could therefore be part of the L3VPN Service Order 362 Management functional block discussed in [RFC4176]. 364 2. CPNP can be used between two adjacent domains to deliver IP 365 interconnection services (e.g., enable, update, disconnect). For 366 example, two Autonomous Systems (ASes) can be connected via 367 several interconnection points. CPNP can be used between these 368 ASes to upgrade existing links, request additional resources, 369 provision a new interconnection point, etc. 371 See for example the framework documented in [ETICS]. 373 3. An integrated Provider can use CPNP to rationalize connectivity 374 provisioning needs related to its service portfolio. A CPNP 375 server function is used by network operations teams. A CPNP 376 interface to invoke CPNP negotiation cycles is exposed to service 377 management teams. 379 4. Service Providers can use CPNP to initiate connectivity 380 provisioning requests towards a number of Network Providers so 381 that to optimize the cost of delivering their services. Although 382 multiple CPNP ordering cycles can be initiated by a Service 383 Provider towards multiple Network Providers, a subset of these 384 orders may actually be put into effect. 386 For example, a cloud Service Provider can use CPNP to request 387 more resources from Network Providers. 389 5. CPNP can be used in Machine-to-Machine (M2M) environments to 390 dynamically subscribe to M2M services (e.g., access to data 391 retrieved by a set of sensors, extend sensor coverage, etc.). 393 Also, Internet of Things (IoT, [RFC6574]) domains may rely on 394 CPNP to enable dynamic provisioning of data produced by involved 395 objects, according to their specific policies, to various 396 external stakeholders such as data analytics and business 397 intelligence companies. Direct CPNP-based interactions between 398 IoT domains and interested parties enable open access to diverse 399 sets of data across the Internet, e.g., from multiple types of 400 sensors, user groups and/or geographical areas. 402 6. A Provider offering cloud services can expose a CPNP interface to 403 allow Customers to dynamically negotiate related service features 404 such as additional storage, processing and networking resources, 405 enhanced security filters, etc. 407 7. In the inter-cloud context (also called cloud of clouds or cloud 408 federation), CPNP can be used to reserve external computing and 409 networking resources in other cloud environments. 411 8. CDN Providers can use CPNP to extend their footprint by 412 interconnecting their CDN infrastructure [RFC6770] (see 413 Figure 1). 415 ,--,--,--. ,--,--,--. 416 ,-' `-. ,-' `-. 417 (CDN Provider 'A')=====(CDN Provider 'B') 418 `-. (CDN-A) ,-' `-. (CDN-B) ,-' 419 `--'--'--' `--'--'--' 421 Figure 1: CDN Interconnection 423 9. Mapping Service Providers (MSPs, [RFC7215]) can use CPNP to 424 enrich their mapping database by interconnecting their mapping 425 system (see Figure 2). This interconnection allows to relax the 426 constraints on PxTR in favour of native LISP forwarding 428 [RFC6830]. Also, it allows to prevent fragmented LISP mapping 429 database. A framework is described in 430 [I-D.boucadair-lisp-idr-ms-discovery]. 432 ,--,--,--. ,--,--,--. 433 ,-' `-. ,-' `-. 434 (Mapping System 'A')===(Mapping System 'B') 435 `-. ,-' `-. ,-' 436 `--'--'--' `--'--'--' 438 Figure 2: LISP Mapping System Interconnect 440 6. CPNP Deployment Models 442 Several CPNP deployment models can be envisaged. Two examples are 443 listed below: 445 o The Customer deploys a CPNP client while one or several CPNP 446 servers are deployed by the Provider. 447 o The Customer does not enable any CPNP client. The Provider 448 maintains a Customer Order Management portal. The Customer can 449 initiate connectivity provisioning quotation orders via the 450 portal; appropriate CPNP messages are then generated and sent to 451 the relevant CPNP server. In this model, both the CPNP client and 452 CPNP server are under the responsibility of the same 453 administrative entity (i.e., Network Provider). 455 Once the negotiation of connectivity provisioning parameters is 456 successfully concluded that is, an order has been placed by the 457 Customer, the actual network provisioning operations are initiated. 458 The specification of related dynamic resource allocation and policy 459 enforcement schemes, as well as how CPNP servers interact with the 460 network provisioning functional blocks at Provider sides are out of 461 the scope of this document. 463 This document does not make any assumption about the CPNP deployment 464 model either. 466 7. CPNP Negotiation Model 468 CPNP runs between a Customer and a Provider carrying service orders 469 from the Customer and respective responses from the Provider to the 470 end of reaching a connectivity service provisioning agreement. As 471 the services offered by the Provider are well-described, by means of 472 the CPP template, the negotiation process is essentially a value- 473 settlement process, where an agreement is pursued on the values of 474 the commonly understood information items (service parameters) 475 included in the service description template. 477 The protocol is transparent to the content that it carries and to the 478 negotiation logic, at Customer and Provider sides, that manipulates 479 the content. 481 The protocol aims at facilitating the execution of the negotiation 482 logic by providing the required generic communication primitives. 484 Since negotiations are initiated and primarily driven by the 485 Customer's negotiation logic, it is reasonable to assume that the 486 Customer can only call for an agreement. An implicit approach is 487 adopted for not overloading the protocol with additional messages. 488 In particular, the acceptance of an offer made by the Provider 489 signals a call for agreement from the Customer. Note that it is 490 almost certain the Provider to accept this call since it refers to an 491 offer that itself made. Of course, at any point the Provider or the 492 Customer may quit the negotiations, each on its own grounds. 494 Based on the above, CPNP adopts a Quotation Order/Offer/Answer model, 495 which proceeds through the following basic steps: 497 1. The client specifies its service requirements via a Provision 498 Quotation Order (PQO). The order may include fixed or loosely 499 defined values in the clauses describing service provisioning 500 characteristics. 502 2. The server declines the PQO, or makes an offer to address the 503 requirements of the PQO, or which may suggests a counter- 504 proposals that partially addresses the requirements of the PQO 505 for specific requirements that cannot be accommodated. 507 3. The client either accepts or declines the offer. Accepting the 508 offer implies a call for agreement. 510 Multiple instances of CPNP may run at Customer or Provider domains. 511 A CPNP client may be engaged simultaneously in multiple negotiations 512 with the same or different CPNP servers (parallel negotiations, see 513 Section 8.11) and a CPNP server may need to negotiate with other 514 Provider(s) as part of negotiations with a CPNP client (cascaded 515 negotiations, see Section 8.10). 517 CPNP relies on various timers to achieve its operations. These 518 timers are used to guide the negotiation logic at both CPNP client 519 and CPNP server sides, particularly in cases where the CPNP client is 520 involved in parallel negotiations with several CPNP servers or in 521 cases where the CPNP server is, in its turn, involved in negotiations 522 with other Providers for processing a given quotation order. Related 523 to the above, CPNP allows the CPNP server to request for more time. 524 This request may be accepted or rejected by the CPNP client. 526 Providers may need to publish available services to the Customers 527 (see Section 4). CPNP may optionally support this functionality. 528 Dedicated templates can be defined for the purpose of service 529 announcements, which will be used by the CPNP clients to initiate 530 their CPNP negotiation cycles. 532 For simplicity, a single Offer/Answer stage is assumed within one a 533 CPNP negotiation cycle. Nevertheless, as stated before, multiple 534 CPNP negotiation cycles can be undertaken by a CPNP client (see 535 Figure 3). 537 The model is flexible as it can accommodate changing conditions over 538 time (e.g., introduction of an additional VPN site). 540 +------+ +------+ +------+ +------+ 541 |Client| |Server| |Client| |Server| 542 +------+ +------+ +------+ +------+ 543 |=====Quotation Order=====>| |=====Quotation Order=====>| 544 |<==========Offer==========| |<==========Offer==========| 545 |===========Accept========>| |==========Decline========>| 547 1-Step Successful Negotiation 1-Step Failed Negotiation 548 Cycle Cycle 550 +------+ +------+ +------+ +------+ 551 |Client| |Server| |Client| |Server| 552 +------+ +------+ +------+ +------+ 553 |===Quotation Order(a)====>| |===Quotation Order(i)====>| 554 |<==========Offer==========| |<==========Offer==========| 555 |==========Decline========>| |==========Decline========>| 556 |===Quotation Order(b)====>| |===Quotation Order(j)====>| 557 |<==========Offer==========| |<==========Offer==========| 558 |===========Accept========>| |==========Decline========>| 559 |===Quotation Order(k)====>| 560 |<==========Offer==========| 561 |==========Decline========>| 562 |===Quotation Order(l)====>| 563 |<==Fail to make an offer==| 565 N-Step Negotiation Cycle: N-Step Negotiation Cycle: 566 Successful Negotiation Failed Negotiation 568 Figure 3: Overall Negotiation Process 570 8. Protocol Overview 572 8.1. Client/Server Communication 574 CPNP is a client/server protocol which is designed to run over any 575 transport protocol with UDP being the default transport mode. No 576 permanent CPNP session needs to be maintained between the client and 577 the server. There is no need to run CPNP over a reliable transport 578 mode because CPNP messages are acknowledged. 580 The server advertises the port (CPNP_PORT) it uses to bind the CPNP 581 service (e.g., using SRV [RFC2782]). The client sends CPNP messages 582 to CPNP_PORT; this port is discovered as per Section 8.2. The same 583 port used as the source port of the request sent to the server MUST 584 be used by the server to reply to that request. 586 CPNP is independent of the IP address family. 588 CPNP retransmission is discussed in Section 11.4. 590 8.2. Server Discovery 592 The CPNP client can be configured with the CPNP server(s) (typically, 593 an IP address together with a port number) using manual or dynamic 594 configuration means. For example, Providers may configure dedicated 595 SRV records or may use a well-known name/address. 597 Discussions about how the client can discovers its the server(s) of 598 its interest are out of the scope of this document. The document 599 assumes that a the required CPNP server can be reached by the CPNP 600 client, thanks to some configuration means. 602 8.3. Policy Configuration on the CPNP Server 604 As an input to its decision-making process, the CPNP server may be 605 connected to various external modules such as: Customer Profiles, 606 Network Topology, Network Resource Management, Orders Repository, AAA 607 and Network Provisioning Manager (an example is shown in Figure 4). 609 These external modules provide inputs to the CPNP server, so that it 610 can: 612 o Check whether a customer is entitled to initiate a provisioning 613 quotation request. 615 o Check whether a customer is entitled to cancel an on-going order. 617 o Check whether administrative data (e.g., billing-related 618 information) have been verified before starting handling the 619 request. 621 o Check whether network capacity is available or additional capacity 622 is required. 624 o Receive guidelines from network design and sales blocks (e.g., 625 pricing, network usage levels, threshold on number of CPP 626 templates that can be processed over a given period of time as a 627 function of the nature of the service to be delivered, etc.). 629 o Transfer completed orders to network provisioning blocks. 631 The above list of CPNP server operations is not exhaustive. 633 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 634 .Business & Administrative Management . 635 .+------------------------++---------------------------+. 636 .| Business Guidelines || Billing & Charging |. 637 .+-----------+------------++-----------+---------------+. 638 . | | . 639 . +-------------------+ | . 640 . . . . . . . . . . . . . . . . .|. . .|. . . . . . . . . 641 . . . . . . . . . . . . . . . . .|. . .|. . . . . . . . . 642 .Order Handling Management | | . 643 . +-------------------+ +-------+-----+--------------+ . 644 . |Network Topology DB+--+ CPNP Server | . 645 . +-------------------+ +-+---+---+---+---+-----+----+ . 646 . | | | | | | . 647 . +------------------------+-+ | | | | | . 648 . | Network Dimensioning | | | | | | . 649 . | & Planning | | | | | | . 650 . +--------------------------+ | | | | | . 651 . +----------------------------+-+ | | | +---+----+ . 652 . | | | | | | AAA | . 653 . | Network +------------+ | | | +--------+ . 654 . | Resource | +------------+-+ | +-+----------+ . 655 . | Management | | Customer | | | Orders | . 656 . | | | Profiles | | | Repository | . 657 . +-----------------+ +--------------+ | +------------+ . 658 . . . . . . . . . . . . . . . . . . . .|. . . . . . . . . 659 +--------------------------------------+----------------+ 660 | Network Provisioning Manager | 661 +-------------------------------------------------------+ 663 Figure 4: Order Handling Management Functional Block 665 The following order handling modes can be also configured on the 666 server: 668 1. Fully automated mode: This mode does not require any action from 669 the administrator when receiving a request for a service. The 670 server can execute its decision-making process related to the 671 orders received and generate corresponding offers. 672 2. Administrative validation checking: Some or all of the server's 673 operations are subject to administrative validation procedures. 674 This mode requires an action from the administrator for every 675 request received. The CPNP methods which can be automatically 676 handled by the server or they are subject to one or several 677 validation administrative checks can be configured on the server. 679 8.4. CPNP Session 681 Both the client and server maintain the following CPNP transport 682 session information: 684 A CPNP session is identified by the following items: 686 o IP address of the client 687 o Client's port number 688 o IP address of the server 689 o Server's port number 691 8.5. Extended CPNP Session 693 An extended PQO session is denoted by a 5-uplet defined as follows: 695 o CPNP session (Section 8.4) 697 o Incremented Sequence Number (Section 11.3) 699 o Customer Agreement Identifier: This is a unique identifier 700 assigned to the order under negotiation by the client 701 (Section 9.1.1). This identifier is also used to identify the 702 agreement that will result from a successful negotiation. 704 o Provider Agreement Identifier: This is a unique identifier 705 assigned to the order under negotiation by the server 706 (Section 9.1.2). This identifier is also used to identify the 707 agreement that will result from a successful negotiation. 709 o Transaction-ID (Section 9.1.3) 711 8.6. CPNP Transaction 713 A CPNP transaction occurs between a client and a server for pursuing, 714 modifying, withdrawing a service agreement and comprises all CPNP 715 messages exchanged between the client and the server, from the first 716 request sent by the client to the final response sent by the server. 717 A CPNP transaction is bound to a CPNP session. 719 Because multiple CPNP transactions can be maintained by the CPNP 720 client, the client must assign an identifier to uniquely identify a 721 given transaction. This identifier is denoted as Transaction-ID. 723 The Transaction-ID must be randomly assigned by the CPNP client, 724 according to the best current practice for generating random numbers 725 [RFC4086] that cannot be guessed easily. Transaction-ID is used for 726 validating CPNP responses received by the client. 728 In the context of a transaction, the client needs to randomly select 729 a sequence number and assign it in the first CPNP message to send. 730 This number is then incremented for each request message is 731 subsequently sent within the on-going CPNP transaction (see 732 Section 11.3). 734 8.7. CPNP Timers 736 CPNP adopts a simple retransmission procedure which relies on a 737 retransmission timer denoted as RETRANS_TIMER and maximum retry 738 threshold. The use of RETRANS_TIMER and a maximum retry threshold 739 are described in Section 11. 741 The response timer (RESPONSE_TIMER) is set by the client to denote 742 the time, in seconds, the client will wait for receiving a response 743 from the server to a provisioning quotation order request (see 744 Section 9.1.6). If the timer expires, the respective quotation order 745 is cancelled by the client and a CANCEL message is generated 746 accordingly. 748 An offer expiration timer (EXPIRE_TIMER) is set by the server to 749 represent the time, in minutes, after which an offer made by the 750 server will be invalid (see Section 9.1.8). 752 8.8. CPNP Operations 754 The current CPNP operations are listed below. They may be augmented, 755 depending on the nature of some transactions or because of security 756 considerations that may necessitate a distinct CPNP client/server 757 authentication phase before negotiation begins. 759 o QUOTATION (Section 9.2.1): 761 This operation is used by the client to initiate a provisioning 762 quotation order. Upon receipt of a QUOTATION request, the server 763 may respond with a PROCESSING, OFFER or a FAIL message. A 764 QUOTATION-initiated transaction can be terminated by a FAIL 765 message. 767 o PROCESSING (Section 9.2.2): 769 This operation is used to inform the remote party that the message 770 (the order quotation or the offer) sent was received and it is 771 processed. This message can also be issued by the server to 772 request more time, in which case the client may reply with an ACK 773 or FAIL message depending on whether more time can or cannot be 774 granted. 776 o OFFER (Section 9.2.3): 778 This operation is used by the server to inform the client about an 779 offer that can best accommodate the requirements indicated in the 780 previously received QUOTATION message. 782 o ACCEPT (Section 9.2.4): 784 This operation is used by the client to confirm the acceptance of 785 an offer made by the server. This message implies a call for 786 agreement. An agreement is reached when an ACK is subsequently 787 received from the server, which is likely to happen; it is rather 788 unlikely the server to reject an offer that it has already made. 790 o DECLINE (Section 9.2.5): 792 This operation is used by the client to reject an offer made by 793 the server. The on-going transaction may not be terminated 794 immediately, e.g., the server/client may issue another offer/ 795 order. 797 o ACK (Section 9.2.6): 799 This operation is used by the server to acknowledge the receipt of 800 an ACCEPT or WITHDRAW message, or by the client to confirm the 801 time extension requested by the server for processing the last 802 received quotation order. 804 o CANCEL (Section 9.2.7): 806 This operation is used by the client to cancel (quit) the on-going 807 transaction. 809 o WITHDRAW (Section 9.2.8): 811 This operation is used by the client to withdraw an agreement. 813 o UPDATE (Section 9.2.9): 815 This operation is used by the client to update an existing 816 agreement. For example, this method can be invoked to add a new 817 site. This method will trigger a new negotiation cycle. 819 o FAIL (Section 9.2.10): 821 This operation is used by the server to indicate that it cannot 822 accommodate the requirements documented in the PQO conveyed in the 823 QUOTATION message or to inform the client about an error 824 encountered when processing the received message. In either case, 825 the message implies that the server is unable to make offers and 826 as such it terminates the on-going transaction. 828 This message is also used by the client to reject a time extension 829 request received from the server (in a PROCESSING message). The 830 message includes a status code for providing explanatory 831 information. 833 The above CPNP primitives are service-independent. CPNP messages may 834 transparently carry service-specific objects which are handled by the 835 negotiation logic at either side. 837 The document specifies the service objects that are required for 838 connectivity provisioning negotiation (see Section 8.9). Additional 839 service-specific objects to be carried in the CPNP messages can be 840 defined in the future for accommodating alternative deployment or 841 other service provisioning needs. 843 8.9. Connectivity Provisioning Documents 845 CPNP makes use of several flavors of Connectivity Provisioning 846 Documents (CPD). These documents follow the CPP template described 847 in [RFC7297]. 849 Requested Connectivity Provisioning Document (Requested CPD): 850 Refers to the CPD included by a CPNP client in a QUOTATION 851 request. 853 Offered Connectivity Provisioning Document (Offered CPD): This 854 document is included by a CPNP server in an OFFER message. Its 855 information reflects the proposal of the server to accommodate all 856 or a subset of the clauses depicted in a Requested CPD. A 857 validity time is associated with the offer made. 859 Agreed Connectivity Provisioning Document (Agreed CPD): If the 860 client accepts an offer made by the server, the Offered CPD is 861 included in an ACCEPT message. This CPD is also included in an 862 ACK message. Thus, a 3-way hand-shaking procedure is followed for 863 successfully concluding the negotiation. 865 Figure 5 shows a typical CPNP negotiation cycle and the use of the 866 different types of Connectivity Provisioning Documents. 868 +------+ +------+ 869 |Client| |Server| 870 +------+ +------+ 871 |======QUOTATION (Requested CPD)=====>| 872 |<============PROCESSING==============| 873 |<========OFFER (Offered CPD)=========| 874 |=============PROCESSING=============>| 875 |=========ACCEPT (Agreed CPD)========>| 876 |<=========ACK (Agreed CPD)===========| 877 | | 879 Figure 5: Connectivity Provisioning Documents 881 A provisioning document can include parameters with fixed values, 882 loosely defined values, or a combination thereof. A provisioning 883 document is said to be concrete if all clauses have fixed values. 885 A typical evolution of a negotiation cycle would start with a 886 quotation order with loosely defined parameters, and then, as offers 887 are made, it would conclude with concrete provisioning document for 888 calling for the agreement. 890 8.10. Child Provisioning Quotation Orders 892 If the server detects that network resources from another Network 893 Provider need to be allocated in order to accommodate the 894 requirements described in a PQO (e.g., in the context of an inter- 895 domain VPN service, additional PE router resources need to be 896 allocated), the server may generate child PQOs to request the 897 appropriate network provisioning operations (see Figure 6). In such 898 situation, the server behaves also as a CPNP client. The server 899 associates the parent order with its child PQOs. This is typically 900 achieved by locally adding the reference of the child PQO to the 901 parent order. 903 +------+ +--------+ +--------+ 904 |Client| |Server A| |Server B| 905 +------+ +--------+ +--------+ 906 | | | 907 |=====QUOTATION=====>| | 908 |<====PROCESSING=====| | 909 | |=====QUOTATION=====>| 910 | |<====PROCESSING=====| 911 | |<=======OFFER=======| 912 | |=====PROCESSING====>| 913 | |=======ACCEPT======>| 914 | |<=======ACK=========| 915 |<=======OFFER=======| | 916 |=====PROCESSING====>| | 917 |=======ACCEPT======>| | 918 |<=======ACK=========| | 919 | | | 921 Figure 6: Example of Child Orders 923 8.11. Negotiations with Multiple CPNP Servers 925 A CPNP client may undertake multiple negotiations in parallel with 926 several servers for practical reasons such as cost optimization and 927 fail-safety. The multiple negotiations may lead to one or many 928 agreements. Multiple negotiations with the same Provider are not 929 precluded. 931 The salient point underlining the parallel negotiations scenario is 932 that although the negotiation protocol is strictly between two 933 parties, the negotiation logic may not necessarily be. The CPNP 934 client negotiation logic may need to collectively drive parallel 935 negotiations, as the negotiation with one server may affect the 936 negotiation with other servers; e.g., it may need to use the 937 responses from all servers as input for determining the messages (and 938 their content) to subsequently send in each individual negotiation. 939 Timing is therefore an important aspect at the client's. The CPNP 940 client needs to have the ability to synchronize the receipt of the 941 responses from the servers. CPNP takes into account this requirement 942 by allowing clients to specify in the QUOTATION message the time by 943 which the server needs to respond (see Section 9.1.6). 945 8.12. State Management 947 Both the client and the server maintain repositories to store on- 948 going orders. How these repositories are maintained is deployment- 949 specific. It is out of scope of this document to elaborate on such 950 considerations. Timestamps are also logged to track state change. 951 Tracking may be needed for various reasons,including regulatory ones. 953 8.12.1. On the Client Side 955 The following lists the states which can be associated with a given 956 order on the client's side: 958 o Created: when the order has been created. It is not handled by 959 the client until the administrator allows to process it. 961 o AwaitingProcessing: when the administrator approved of processing 962 a created order and the order has not been handled yet. 964 o PQOSent: when the order has been sent to the server. 966 o ServerProcessing: when the server has confirmed the receipt of the 967 order. 969 o OfferReceived: when an offer has been received from the server. 971 o OfferProcessing: when a received offer is currently processed by 972 the client. 974 o AcceptSent: when the client confirmed the offer to the server. 976 o AcceptAck: when the offer is acknowledged by the server. 978 o Cancelled: when the order has failed or cancelled. 980 +------------------+ 981 | Created |-----------------+ 982 +------------------+ | 983 | | 984 v | 985 +------------------+ | 986 |AwaitingProcessing|----------------+| 987 +------------------+ || 988 | || 989 QUOTATION || 990 v || 991 +------------------+ || 992 | PQOSent |---CANCEL------+|| 993 +------------------+ vvv 994 | +-----+ 995 PROCESSING | | 996 v | | 997 +------------------+ CANCEL | C | 998 | ServerProcessing |------------>| A | 999 +------------------+ FAIL | N | 1000 | | C | 1001 | | E | 1002 OFFER | L | 1003 | | L | 1004 v | E | 1005 +------------------+ | D | 1006 | OfferReceived |---CANCEL--->| | 1007 +------------------+ | | 1008 | PROCESSING +-----+ 1009 v ^^^ 1010 +------------------+ ||| 1011 | OfferProcessing |---DECLINE-----+|| 1012 +------------------+ || 1013 | ACCEPT || 1014 v || 1015 +------------------+ || 1016 | AcceptSent |---CANCEL-------+| 1017 +------------------+ | 1018 | ACK | 1019 v | 1020 +------------------+ | 1021 | AcceptAck |---WITHDRAW------+ 1022 +------------------+ 1024 Figure 7: CPNP Finite State Machine (Client Side) 1026 8.12.2. On the Server Side 1028 The following lists the states which can be associated with a given 1029 order and a corresponding offer on the server's side: 1031 o PQOReceived: when the order has been received from the client. 1033 o AwaitingProcessing: when the order is being processed by the 1034 server. An action from the server administrator may be needed. 1036 o OfferProposed: when the request has been successfully handled and 1037 an offer has been sent to the client. 1039 o ProcessingReceived: when the server received a PROCESSING for an 1040 offer sent to the client. 1042 o AcceptReceived: when the server received a confirmation for the 1043 offer from the client. 1045 o AcceptAck: when the server acknowledged the offer (accepted by 1046 client) to the client. 1048 o Cancelled: when the order has failed to be met or it has been 1049 cancelled by the client. Associate resources must be released in 1050 the latter case, if prior reserved. 1052 o ChildCreated: when a child order has been created in cases where 1053 resources from another Network Provider are needed. 1055 o ChildPQOSent: when a child order has been sent to the remote 1056 server. 1058 o ChildServerProcessing: when a child order is currently processed 1059 by the remote server. 1061 o ChildOfferReceived: when an offer has been received to a child 1062 order from the remote server. 1064 o ChildOfferProcessing: when a received offer to a child order is 1065 currently processed. 1067 o ChildAcceptSent: when the child offer (offer received from the 1068 remote server in response to a child order) is confirmed to the 1069 remote server. 1071 o ChildAcceptAck: when an accepted child offer is acknowledged by 1072 the remote server. 1074 +------------------+ 1075 +---------------------| ChildCreated | 1076 | +------------------+ 1077 v | ^ 1078 +------------------+ | | 1079 | ChildPQOSent |----------------+| Q 1080 +------------------+ || U 1081 | || O 1082 QUOTATION || T 1083 v || A +--------------------+ 1084 +---------------------+ CANCEL || T | PQOReceived | 1085 |ChildServerProcessing|------------+|| I +--------------------+ 1086 +---------------------+ FAIL vvv O | | 1087 | +-----+ N CANCEL | 1088 PROCESSING | |<---|-------+ PROCESSING 1089 v | | | v 1090 +------------------+ | | +------------------------+ 1091 |ChildOfferReceived|----CANCEL---| C |<--| AwaitingProcessing | 1092 +------------------+ | A | +------------------------+ 1093 | | N | ^ | OFFER 1094 OFFER | C | | +------------------+ 1095 | | E | ::= 1234 ... 1235 ::= 1236 ... 1237 ::= 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 ::= ... 1252 ::= 1253 1254 1256 Figure 9: The RBNF format of the Connectivity Provisioning Document 1257 (CPD) 1259 9.1.10. Information Elements 1261 An Information Element (IE) is an optional object which can be 1262 included in a CPNP message. 1264 9.1.10.1. Customer Description 1266 The client may include administrative information such as: 1268 o Name 1269 o Contact Information 1271 The format of this Information Element is as follows: 1273 ::= 1274 ::= [] 1275 [ ...] 1277 9.1.10.2. Provider Description 1279 The server may include administrative information in an offer such 1280 as: 1282 o Name 1283 o AS Number ([RFC6793]) 1284 o Contact Information 1286 The format of this Information Element is as follows: 1288 ::= [] 1290 9.1.10.3. Negotiation Options 1292 The client may include some negotiation options such as: 1294 o Cost: the client may include an empty or a preferred COST 1295 attribute to request the cost from the server. The server will 1296 provide the cost information in the response. 1297 o Setup purpose: A client may request to setup a connectivity only 1298 for testing purposes during a limited period. The order can be 1299 extended to become permanent if the client was satisfied during 1300 the test period. This operation is achieved using UPDATE method. 1302 Other negotiation options may be defined in the future. 1304 The format of this Information Element is as follows: 1306 ::= [][] 1308 9.2. Operation Messages 1310 This section specifies the RBNF format of CPNP operation messages. 1311 The following operation codes are used: 1313 1: QUOTATION (Section 9.2.1) 1314 2: PROCESSING (Section 9.2.2) 1315 3: OFFER (Section 9.2.3) 1316 4: ACCEPT (Section 9.2.4) 1317 5: DECLINE (Section 9.2.5) 1318 6: ACK (Section 9.2.6) 1319 7: CANCEL (Section 9.2.7) 1320 8: WITHDRAW (Section 9.2.8) 1321 9: UPDATE (Section 9.2.9) 1322 10: FAIL (Section 9.2.10) 1324 9.2.1. QUOTATION 1326 The format of the QUOTATION message is shown below: 1328 ::= 1329 1330 1331 1332 1333 [] 1334 1335 [...] 1337 A QUOTATION message must include an order identifier which is 1338 generated by the client. Because several orders can be issued to 1339 several servers, the QUOTATION message must also include a 1340 Transaction-ID. 1342 The message may include an EXPECTED_RESPONSE_TIME which indicates by 1343 when the client is expecting to receive an offer from the server. 1344 QUOTATION message must also include a requested connectivity 1345 provisioning document. 1347 When the client sends the QUOTATION message to the server, the state 1348 of the order changes to "PQOSent". 1350 9.2.2. PROCESSING 1352 The format of the PROCESSING message is shown below: 1354 ::= 1355 1356 1357 1358 1359 1360 [] 1362 Upon receipt of a QUOTATION message, the server proceeds with parsing 1363 rules (see Section 10). If no error is encountered, the server 1364 generates a PROCESSING response to the client to indicate the PQO has 1365 been received and it is being processed. The server must generate an 1366 order identifier which identifies the order in its local order 1367 repository. The server MUST copy the content of 1368 CUSTOMER_AGREEMENT_IDENTIFIER and TRANSACTION_ID fields as conveyed 1369 in the QUOTATION message. The server may include an 1370 EXPECTED_OFFER_TIME by when it expects to make an offer to the 1371 client. 1373 Upon receipt of a PROCESSING message, the client verifies whether it 1374 has issued a PQO to that server and which contains the 1375 CUSTOMER_AGREEMENT_IDENTIFIER and TRANSACTION_ID. If no such PQO is 1376 found, the PROCESSING message is silently ignored. If a PQO is 1377 found, the client may check if it accepts the EXPECTED_OFFER_TIME and 1378 then, it changes to state of the order to "ServerProcessing". 1380 If more time is required by the server to process the quotation 1381 order, it may send a PROCESSING message that includes a new 1382 EXPECTED_OFFER_TIME. The client can answer with an ACK message if 1383 more time is granted (Figure 10) or with a FAIL message if the time 1384 extension is rejected (Figure 11). 1386 +------+ +------+ 1387 |Client| |Server| 1388 +------+ +------+ 1389 |=======QUOTATION(Requested CPD)=====>| 1390 |<========PROCESSING(time1)===========| 1391 ... 1392 |<========PROCESSING(MoreTime)========| 1393 |============ACK(TimeGranted)========>| 1394 ... 1395 |<=========OFFER(Offered CPD)=========| 1396 |=============PROCESSING=============>| 1397 |==========ACCEPT(Agreed CPD)========>| 1398 |<==========ACK(Agreed CPD)===========| 1399 | | 1401 Figure 10: Request more negotiation time: Granted 1402 +------+ +------+ 1403 |Client| |Server| 1404 +------+ +------+ 1405 |=======QUOTATION(Requested CPD)=====>| 1406 |<========PROCESSING(time1)===========| 1407 ... 1408 |<========PROCESSING(MoreTime)========| 1409 |===========FAIL(TimeRejected)=======>| 1411 Figure 11: Request more negotiation time: Rejected 1413 9.2.3. OFFER 1415 The format of the OFFER message is shown below: 1417 ::= 1418 1419 1420 1421 1422 1423 1424 1425 1426 [...] 1428 The server answers with an OFFER message to a QUOTATION request 1429 received from the client. The offer will be considered as rejected 1430 by the client if no confirmation (ACCEPT message sent by the client) 1431 is received by the server before the expiration of the validity time. 1433 9.2.4. ACCEPT 1435 The format of the ACCEPT message is shown below: 1437 ::= 1438 1439 1440 1441 1442 1443 1444 1445 [...] 1447 This message is used by a client to confirm the acceptance of an 1448 offer received from a server. The fields of this message are copied 1449 from the received OFFER message. 1451 9.2.5. DECLINE 1453 The format of the DECLINE message is shown below: 1455 ::= 1456 1457 1458 1459 1460 1461 1463 The client can issue a DECLINE message to reject an offer. 1464 CUSTOMER_AGREEMENT_IDENTIFIER, PROVIDER_AGREEMENT_IDENTIFIER, 1465 TRANSACTION_ID, and NONCE are used by the server as keys to find the 1466 corresponding order. If an order matches, the server changes the 1467 state of this order to "Cancelled" and then returns an ACK with a 1468 copy of the requested CPD to the requesting client. 1470 If no order is found, the server returns a FAIL message to the 1471 requesting client. 1473 A flow example is shown in Figure 12. 1475 +------+ +------+ 1476 |Client| |Server| 1477 +------+ +------+ 1478 |=======QUOTATION(Requested CPD)=====>| 1479 |<============PROCESSING==============| 1480 |<=========OFFER(Offered CPD)=========| 1481 |=============PROCESSING=============>| 1482 |===============DECLINE==============>| 1483 |<================ACK=================| 1484 | | 1486 Figure 12: DECLINE Flow Example 1488 9.2.6. ACK 1490 The format of the ACK message is shown below: 1492 ::= 1493 1494 1495 1496 1497 1498 [] 1500 [] 1501 [...] 1503 This message is issued by the server to close a CPNP transaction or 1504 by a client to grant more negotiation time to the server. 1506 This message is sent by the server as a response to an ACCEPT, 1507 WITHDRAW, DECLINE, or CANCEL message. In such case, the ACK message 1508 must include the copy of the Connectivity Provisioning Document as 1509 stored by the server, in particular: 1511 o A copy of the requested/offered CPD is included by the server if 1512 it successfully handled a CANCEL message. 1513 o A copy of the updated CPD is included by the server if it 1514 successfully handled an UPDATE message. 1515 o A copy of the offered CPD is included by the server if it 1516 successfully handled an ACCEPT message in the context of a 1517 QUOTATION transaction. 1518 o An empty CPD is included by the server if it successfully handled 1519 a DECLINE message. 1521 A client may issue an ACK message as a response to a more time 1522 request (conveyed in PROCESSING) received from the server. In such 1523 case, the ACK message must include an EXPECTED_RESPONSE_TIME that is 1524 likely to be set to the time extension requested by the server. 1526 9.2.7. CANCEL 1528 The format of the CANCEL message is shown below: 1530 ::= 1531 1532 1533 1534 1535 [] 1537 The client can issue a CANCEL message at any stage during the CPNP 1538 negotiation process before an agreement is reached. 1539 CUSTOMER_AGREEMENT_IDENTIFIER and TRANSACTION_ID are used by the 1540 server as keys to find the corresponding order. If a quotation order 1541 matches, the server changes the state of this quotation order to 1542 "Cancelled" and then returns an ACK with a copy of the requested CPD 1543 to the requesting client. 1545 If no quotation order is found, the server returns a FAIL message to 1546 the requesting client. 1548 9.2.8. WITHDRAW 1550 The format of the WITHDRAW message is shown below: 1552 ::= 1553 1554 1555 1556 1557 1558 1559 [] 1560 [...] 1562 This message is used to withdraw an offer already subscribed by the 1563 Customer. Figure 13 shows a typical usage of this message. 1565 +------+ +------+ 1566 |Client| |Server| 1567 +------+ +------+ 1568 |============WITHDRAW(CPD)===========>| 1569 |<============PROCESSING==============| 1570 |<===========ACK(Empty CPD)===========| 1571 | | 1573 Figure 13: WITHDRAW Flow Example 1575 The CPNP must include the same CUSTOMER_AGREEMENT_IDENTIFIER, 1576 PROVIDER_AGREEMENT_IDENTIFIER, and NONCE as those used when creating 1577 the order. 1579 Upon receipt of a WITHDRAW message, the server checks whether an 1580 order matching the request is found. If an order is found, the state 1581 of the order is changed to "Cancelled" and an ACK message including 1582 an Empty CPD is returned to the requesting client. If no order is 1583 found, the server returns a FAIL message to the requesting client. 1585 9.2.9. UPDATE 1587 The format of the UPDATE message is shown below: 1589 ::= 1590 1591 1592 1593 1594 1595 1596 1597 1598 [...] 1600 This message is sent by the CPNP client to update an existing 1601 connectivity provisioning agreement. The CPNP must include the same 1602 CUSTOMER_AGREEMENT_IDENTIFIER, PROVIDER_AGREEMENT_IDENTIFIER, and 1603 NONCE as those used when creating the order. The CPNP client 1604 includes a new CPD which integrates the requested modifications. A 1605 new Transaction_ID must be assigned by the client. 1607 Upon receipt of an UPDATE message, the server checks whether an 1608 order, having state "Completed", matches 1609 CUSTOMER_AGREEMENT_IDENTIFIER, PROVIDER_AGREEMENT_IDENTIFIER, and 1610 NONCE. 1612 o If no order is found, the CPNP server generates a FAIL error with 1613 the appropriate error code. 1614 o If an order is found, the server checks whether it can honor the 1615 request: 1617 * A FAIL message is sent to the client if the server cannot honor 1618 the request. The client may initiate a new PQO negotiation 1619 cycle. 1620 * An OFFER message including the updated connectivity 1621 provisioning document is sent to the client. For example, the 1622 server maintains an order for provisioning a VPN service that 1623 connects sites A, B and C. If the client sends an UPDATE 1624 message to remove site C, only sites A and B will be included 1625 in the OFFER sent by the server to the requesting client. 1627 A flow chart that illustrates the use of UPDATE operation is shown in 1628 Figure 14. 1630 +------+ +------+ 1631 |Client| |Server| 1632 +------+ +------+ 1633 |=========UPDATE(Requested CPD)======>| 1634 |<============PROCESSING==============| 1635 |<=========OFFER(Updated CPD)=========| 1636 |=============PROCESSING=============>| 1637 |==========ACCEPT(Updated CPD)=======>| 1638 |<==========ACK(Updated CPD)==========| 1639 | | 1641 Figure 14: UPDATE Flow Example 1643 9.2.10. FAIL 1645 The format of the FAIL message is shown below: 1647 ::= 1648 1649 1650 1651 1652 1653 1655 This message is sent in the following cases: 1657 o The server can not honor an order received from the client (i.e., 1658 received in a QUOTATION or UPDATE request). 1659 o The server encounters an error when processing a CPNP request 1660 received from the client. 1661 o The client can not grant more time to a the server. This is a 1662 response to a more time request conveyed in a PROCESSING message. 1664 The status code indicates the error code. The following codes are 1665 supported: 1667 1 (Message Validation Error): 1668 The message can not be validated (see Section 10). 1669 2 (Authentication Required): 1670 The request cannot be handled because authentication is 1671 required. 1672 3 (Authorization Failed): 1673 The request cannot be handled because authorization failed. 1674 4 (Administratively prohibited): 1675 The request can not be handled because of administrative 1676 policies. 1677 5 (Out of Resources): 1678 The request can not be honored because there is not enough 1679 capacity. 1680 6 (Network Presence Error): 1681 The request can not be honored because there is no network 1682 presence. 1683 7 (More Time Rejected): 1684 The request to extend the time negotiation is rejected by the 1685 client. 1687 10. Message Validation 1689 Both client and server proceed with CPNP message validation. The 1690 following tables summarize the validation checks to be followed. 1692 10.1. On the Client Side 1694 Operation Validation Checks 1695 ------------ -------------------------------------------------------- 1696 PROCESSING {Source IP address, source port, destination IP address, 1697 destination port, Transaction-ID, Customer Order 1698 Identifier} must match an existing PQO with a state set 1699 to "PQOSent". The sequence number carried in the packet 1700 must be larger than the sequence number maintained by 1701 the client. 1702 OFFER {Source IP address, source port, destination IP address, 1703 destination port, Transaction-ID, Customer Order 1704 Identifier} must match an existing order with state set 1705 to "PQOSent" or {Source IP address, source port, 1706 destination IP address, destination port, Transaction- 1707 ID, Customer Order Identifier, Provider Order 1708 Identifier} must match an existing order with a state 1709 set to "ServerProcessing". The sequence number carried 1710 in the packet must be larger than the sequence number 1711 maintained by the client. 1712 ACK {Source IP address, source port, destination IP address, 1713 (QUOTATION destination port, Transaction-ID, Customer Order 1714 Transaction) Identifier, Provider Order Identifier, Offered 1715 Connectivity Provisioning Order} must match an order 1716 with a state set to "AcceptSent". The sequence number 1717 carried in the packet must be larger than the sequence 1718 number maintained by the client. 1719 ACK (UPDATE {Source IP address, source port, destination IP address, 1720 Transaction) destination port, Transaction-ID, Customer Order 1721 Identifier, Provider Order Identifier, Updated 1722 Connectivity Provisioning Order} must match an order 1723 with a state set to "AcceptSent". The sequence number 1724 carried in the packet must be larger than the sequence 1725 number maintained by the client. 1726 ACK {Source IP address, source port, destination IP address, 1727 (WITHDRAW destination port, Transaction-ID, Customer Order 1728 Transaction) Identifier, Provider Order Identifier, Empty 1729 Connectivity Provisioning Order} must match an order 1730 with a state set to "Cancelled". The sequence number 1731 carried in the packet must be larger than the sequence 1732 number maintained by the client. 1734 10.2. On the Server Side 1736 Method Validation Checks 1737 ---------- ---------------------------------------------------------- 1738 QUOTATION The source IP address passes existing access filters (if 1739 any). The sequence number carried in the packet must not 1740 be less than the sequence number maintained by the server. 1741 PROCESSING The sequence number carried in the packet must be larger 1742 than the sequence number maintained by the server. 1743 ACCEPT {Source IP address, source port, destination IP address, 1744 destination port, Transaction-ID, Customer Order 1745 Identifier, Provider Order Identifier, Nonce, Offered 1746 Connectivity Provisioning Order} must match an order with 1747 state set to "OfferProposed" or "ProcessngReceived". The 1748 sequence number carried in the packet must be larger than 1749 the sequence number maintained by the server. 1750 DECLINE {Source IP address, source port, destination IP address, 1751 destination port, Transaction-ID, Customer Order 1752 Identifier, Provider Order Identifier, Nonce} must match 1753 an order with state set to "OfferProposed" or 1754 "ProcessngReceived". The sequence number carried in the 1755 packet must be larger than the sequence number maintained 1756 by the server. 1757 UPDATE The source IP address passes existing access filters (if 1758 any) and {Customer Order Identifier, Provider Order 1759 Identifier, Nonce} must match an existing order with state 1760 "Completed". 1761 WITHDRAW The source IP address passes existing access filters (if 1762 any) and {Customer Order Identifier, Provider Order 1763 Identifier, Nonce} must match an existing order with state 1764 "Completed". 1766 11. Theory of Operation 1768 Both CPNP client and server proceeds to message validation checks as 1769 specified in Section 10. 1771 11.1. Client Behavior 1773 11.1.1. Order Negotiation Cycle 1775 To place a provisioning quotation order, the client initiates first a 1776 local quotation order object identified by a unique identifier 1777 assigned by the client. The state of the quotation order is set to 1778 "Created". The client then generates a QUOTATION request which 1779 includes the assigned identifier, possibly an expected response time, 1780 a Transaction-ID and a Requested Connectivity Provisioning Document. 1782 The client may include additional Information Elements such as 1783 Negotiation Options. 1785 The client may be configured to not enforce negotiation checks on 1786 EXPECTED_OFFER_TIME; if so no EXPECTED_RESPONSE_TIME attribute (or 1787 EXPECTED_RESPONSE_TIME set to infinite) should be included in the 1788 quotation order. 1790 Once the request is sent to the server, the state of the request is 1791 set to "PQOSent" and a timer, if a response time is included in the 1792 quotation order, is set to the expiration time as included in the 1793 QUOTATION request. The client also maintains a copy of the extended 1794 transport session details used to generate the QUOTATION request. 1795 The CPNP client must listen on the same port number that it used to 1796 send the QUOTATION request. 1798 If no answer is received from the server before the retransmission 1799 timer expires (i.e., RETRANS_TIMER, Section 8.7), the client proceeds 1800 to retransmission until maximum retry is reached (i.e., 3 times). 1801 The same sequence number is used for retransmitted packets. 1803 If a FAIL message is received, the client may decide to issue another 1804 (corrected) request towards the same server, cancel the local order, 1805 or contact another server. The behavior of the client depends on the 1806 error code returned by the server in the FAIL message. 1808 If a PROCESSING message matching the CPNP transport session is 1809 received, the client updates the CPNP session with the 1810 PROVIDER_AGREEMENT_IDENTIFIER information. If the client does not 1811 accept the expected offer time that may have been indicated in the 1812 PROCESSING message, the client may decide to cancel the quotation 1813 order. If the client accepts the EXPECTED_OFFER_TIME, it changes the 1814 state of the order to "ServerProcessing" and sets a timer to the 1815 value of EXPECTED_OFFER_TIME. If no offer is made before the timer 1816 expires, the client changes the state of the order to "Cancelled". 1818 As a response to a more time request (conveyed in a PROCESSING 1819 message that included a new EXPECTED_OFFER_TIME), the client may 1820 grant this extension by issuing an ACK message or reject the time 1821 extension with a FAIL message having a status code set to "More Time 1822 Rejected". 1824 If an OFFER message matching the extended CPNP session is received, 1825 the client checks if a PROCESSING message having the same 1826 PROVIDER_AGREEMENT_IDENTIFIER has been received from the server. If 1827 a PROCESSING message was already received for the same order but the 1828 PROVIDER_AGREEMENT_IDENTIFIER does not match the identifier included 1829 in the OFFER message, the client ignores silently the message. If a 1830 PROCESSING message having the same PROVIDER_AGREEMENT_IDENTIFIER was 1831 already received and matches the CPNP transaction identifier, the 1832 client changes the state of the order to "OfferReceived" and sets a 1833 timer to the value of VALIDITY_OFFER_TIME indicated in the OFFER 1834 message. 1836 If an offer is received from the server (i.e., as documented in an 1837 OFFER message), the client may accept or reject the offer. The 1838 client accepts the offer by generating an ACCEPT message which 1839 confirms that the client agrees to subscribe to the offer documented 1840 in the OFFER message; the state of the order is passed to 1841 "AcceptSent". The transaction is terminated if an ACK message is 1842 received from the server. If no ACK is received from the server, the 1843 client proceeds with the re-transmission of the ACCEPT message. 1845 The client may also decide to reject the offer by sending a DECLINE 1846 message. The state of the order is set by the client to "Cancelled". 1847 If an offer is not acceptable by the client, the client may decide to 1848 contact a new server or submit another order to the same server. 1849 Guidelines to issue an updated order or terminate the negotiation are 1850 specific to the client. 1852 11.1.2. Order Withdrawal Cycle 1854 A client may withdraw a completed order. This is achieved by issuing 1855 a WITHDRAW message. This message must include Customer Order 1856 Identifier, Provider Identifier and Nonce returned during the order 1857 negotiation cycle specified in Section 11.1.1. 1859 If no ACK is received from the server, the client proceeds with the 1860 re-transmission of the message. 1862 11.1.3. Order Update Cycle 1864 A client may update a completed order. This is achieved by issuing 1865 an UPDATE message. This message must include Customer Order 1866 Identifier, Provider Order Identifier and Nonce returned during the 1867 order negotiation cycle specified in Section 11.1.1. The client must 1868 include in the UPDATE message an updated CPD with the requested 1869 changes. 1871 Subsequent messages exchange is similar to what is documented in 1872 Section 11.1.1. 1874 11.2. Server Behavior 1876 11.2.1. Order Processing 1878 Upon receipt of a QUOTATION message from a client, the server sets a 1879 CPNP session, stores Transaction-ID and generates a Provider Order 1880 Identifier. Once preliminary validation checks are completed ( 1881 Section 10), the server may return a PROCESSING message to notify the 1882 client the quotation order is received and it is under processing; 1883 the server may include an expected offer time to notify the client by 1884 when an offer will be proposed. An order with state 1885 "AwaitingProcessing" is created by the server. The server runs its 1886 decision-making process to decide which offer it can make to honor 1887 the received order. The offer should be made before the expected 1888 offer time expires. 1890 If the server cannot make an offer, it sends backs a FAIL message 1891 with the appropriate error code. 1893 If the server requires more negotiation time, it must send a 1894 PROCESSING message with a new EXPECTED_OFFER_TIME. The client may 1895 grant this extension by issuing an ACK message or reject the time 1896 extension with a FAIL message having a status code set to "More Time 1897 Rejected". If the client doesn't grant more time, the server must 1898 answer before the initial expected offer time; otherwise the client 1899 will ignore the quotation order. 1901 If the server can honor the request or it can make an offer that meet 1902 some of the requirements, it creates an OFFER message. The server 1903 must indicate the Transaction-ID, Customer Order Identifier as 1904 indicated in the QUOTATION message, and the Provider Order Identifier 1905 generated for this order. The server must also include Nonce and the 1906 offered Connectivity Provisioning Document. The server includes an 1907 offer validity time as well. Once sent to the client, the server 1908 changes the state of the order to "OfferSent" and a timer set to the 1909 validity time is initiated. 1911 If the server determines that additional network resources from 1912 another network provider are needed to accommodate a quotation order, 1913 it will create child PQO(s) and will behave as a CPNP client to 1914 negotiate child PQO(s) with possible partnering providers (see 1915 Figure 6). 1917 If no PROCESSING, ACCEPT or DECLINE message is received before the 1918 expiry of the RETRANS_TIMER, the server re-sends the same offer to 1919 the client. This procedure is repeated until maximum retry is 1920 reached. 1922 If an ACCEPT message is received before the offered validity time 1923 expires, the server proceeds with validation checks as specified in 1924 Section 10. The state of the corresponding order is passed to 1925 "AcceptReceived". The server sends back an ACK message to terminate 1926 the order processing cycle. 1928 If a CANCEL/DECLINE message is received, the server proceeds with the 1929 cancellation of the order. The state of the order is then passed to 1930 "Cancelled". 1932 11.2.2. Order Withdrawal 1934 A client may withdraw a completed order by issuing a WITHDRAW 1935 message. Upon receipt of a WITHDRAW message, the server proceeds 1936 with the validation checks, as specified in Section 10. 1938 o If the checks fail, a FAIL message is sent back to the client with 1939 the appropriate error code. 1941 o If the checks succeed, the server clears the clauses of the 1942 Connectivity Provisioning Document, changes the state of the order 1943 to "Cancelled", and sends back an ACK message with an Empty 1944 Connectivity Provisioning Document. 1946 11.2.3. Order Update 1948 A client may update an order by issuing an UPDATE message. Upon 1949 receipt of an UPDATE message, the server proceeds with the validation 1950 checks as specified in Section 10. 1952 o If the checks fail, a FAIL message is sent back to the client with 1953 the appropriate error code. 1954 o Subsequent messages exchange is similar to what is specified in 1955 Section 11.1.1. The server should generate a new Nonce value to 1956 be included in the offer made to the client. 1958 11.3. Sequence Numbers 1960 In each transaction, sequence numbers are used to protect the 1961 transaction against replay attacks. Each communicating partner of 1962 the transaction maintains two sequence numbers, one for incoming 1963 packets and one for outgoing packets. When a partner receives a 1964 message, it will check whether the sequence number in the message is 1965 larger than the incoming sequence number maintained locally. If not, 1966 the messages will be discarded. If the message is proved to be 1967 legal, the value of the incoming sequence number will be replaced by 1968 the value of the sequence number in the message. When a partner 1969 sends out a message, it will insert the value of outgoing sequence 1970 number into the message and increase the outgoing sequence number 1971 maintained locally by 1. 1973 11.4. Message Re-Transmission 1975 If a transaction partner sends out a message and does not receive any 1976 expected reply before the retransmission timer expires (i.e., 1977 RETRANS_TIMER), a transaction partner will try to re-transit the 1978 messages. An exception is the last message (e.g., ACK) sent from the 1979 server in a transaction. After sending this message, the 1980 retransmission timer will be disabled since no additional feedback is 1981 expected. 1983 In addition, if the partner receives a re-sent last incoming packet, 1984 the partner can also send out the answer to the incoming packet with 1985 a limited frequency. If no answer was generated at the moment, the 1986 partner needs to generate a PROCESSING message as the answer. 1988 To benefit message re-transmission, a partner could also store the 1989 last incoming packet and the associated answer. Note that the times 1990 of re-transmission could be decided by the local policy and re- 1991 transmission will not cause any change of sequence numbers. 1993 12. Operational Guidelines 1995 12.1. Logging on the CPNP Server 1997 The CPNP server SHOULD be configurable to log various events and 1998 associated information. Such information includes: 2000 o Client's IP address 2001 o Any event change (e.g., new quotation order, offer sent, order 2002 confirm, order cancellation, order withdraw, etc.) 2003 o Timestamp 2005 12.2. Business Guidelines & Objectives 2007 The CPNP server can operate in the following modes: 2009 1. Fully automated mode: The CPNP server is provisioned with a set 2010 of business guidelines and objectives that will be used as an 2011 input to the decision-making process. The CPNP server will 2012 service received orders that falls into these business 2013 guidelines; otherwise requests will be escalated to an 2014 administrator that will formally validate/invalidate an order 2015 request. The set of policies to be configured to the CPNP server 2016 are specific to each administrative entity managing a CPNP 2017 server. 2019 2. Administrative-based mode: This mode assumes some or all CPNP 2020 server' operations are subject to a formal administrative 2021 validation. CPNP events will trigger appropriate validation 2022 requests that will be forwarded to the contact person(s) or 2023 department which is responsible for validating the orders. 2024 Administrative validation messages are relayed using another 2025 protocol (e.g., SMTP) or a dedicated tool. 2027 Business guidelines are local to each administrative entity. How 2028 validation requests are presented to an administrator are out of 2029 scope of this document; each administrative entity may decide the 2030 appropriate mechanism to enable for that purpose. 2032 13. Security Considerations 2034 Means to defend the server against denial-of-service attacks must be 2035 enabled. For example, access control lists (ACLs) can be enforced on 2036 the client, the server or the network in between, to allow a trusted 2037 client to communicate with a trusted server. 2039 The client and the server should be mutually authenticated. Out of 2040 band mechanisms can be used instead of integrating them into CPNP. 2042 The client must silently discard CPNP responses received from unknown 2043 CPNP servers. The use of a randomly generated Transaction-ID makes 2044 it hard to forge a response from a server with a spoofed IP address 2045 belonging to a legitimate CPNP server. Furthermore, CPNP demands 2046 that messages from the server must include correct identifiers of the 2047 orders. Two order identifiers are used: one generated by the client 2048 and a second one generated by the server. 2050 The Provider must enforce means to protect privacy-related 2051 information included the documents (see Section 8.9) exchanged using 2052 CPNP messages [RFC6462]. In particular, this information must not be 2053 revealed to external parties without the consent of Customers. 2054 Providers should enforce policies to make Customer fingerprinting 2055 difficult to achieve. For more discussion about privacy, refer to 2056 [RFC6462][RFC6973]. 2058 The NONCE and the Transaction ID attributes provide sufficient 2059 randomness and can effectively tolerate attacks raised by off-line 2060 adversaries, who do not have the capability of eavesdropping and 2061 intercepting the packets transported between the client and the 2062 server. Only authorized clients must be able to modify agreed CPNP 2063 orders. The use of a randomly generated NONCE by the server makes it 2064 hard to modify an agreement on behalf of a malicious third-party. 2066 The sequence numbers included in the CPNP messages can be used to 2067 detect replay attacks and antique packets intercepted from on-going 2068 transactions may be re-sent. However, the protocol in its current 2069 version may be vulnerable to replay attacks where the replayed 2070 messages are intercepted from antique transactions. Although the 2071 Transaction ID provided by the client could protect inter-transaction 2072 replay attacks, no protection is provided for the server to deal with 2073 this type of attack. 2075 The protocol does not provide security mechanisms to protect the 2076 confidentiality and integrity of the packets transported between the 2077 client and the server. An underlying security protocol such as 2078 (e.g., DTLS [RFC6347], IPsec) could be used to protect the integrity 2079 and confidentiality for the protocol. In this case, if it is 2080 possible to provide an Automated Key Management (AKM) and associate 2081 each transaction with a different key, inter- transaction replay 2082 attacks can naturally be addressed. If the client and the server use 2083 a single key, an additional mechanism should be provided to protect 2084 inter-transaction replay attacks between them. 2086 The deployment option of a Customer Order Management portal operated 2087 by a trusted third-party (see Section 6) may facilitate the efficient 2088 resolution of the aforementioned security concerns. 2090 14. IANA Considerations 2092 This document does not request any IANA action. 2094 15. Acknowledgements 2096 Thanks to Diego R. Lopez for his comments. 2098 16. References 2100 16.1. Normative References 2102 [RFC1123] Braden, R., Ed., "Requirements for Internet Hosts - 2103 Application and Support", STD 3, RFC 1123, 2104 DOI 10.17487/RFC1123, October 1989, 2105 . 2107 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 2108 Requirement Levels", BCP 14, RFC 2119, 2109 DOI 10.17487/RFC2119, March 1997, 2110 . 2112 [RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker, 2113 "Randomness Requirements for Security", BCP 106, RFC 4086, 2114 DOI 10.17487/RFC4086, June 2005, 2115 . 2117 [RFC5511] Farrel, A., "Routing Backus-Naur Form (RBNF): A Syntax 2118 Used to Form Encoding Rules in Various Routing Protocol 2119 Specifications", RFC 5511, DOI 10.17487/RFC5511, April 2120 2009, . 2122 16.2. Informative References 2124 [ETICS] EU FP7 ETICS Project, "Economics and Technologies of 2125 Inter-Carrier Services", January 2014, . 2129 [I-D.boucadair-lisp-idr-ms-discovery] 2130 Boucadair, M. and C. Jacquenet, "LISP Mapping Service 2131 Discovery at Large", draft-boucadair-lisp-idr-ms- 2132 discovery-01 (work in progress), March 2016. 2134 [RFC2782] Gulbrandsen, A., Vixie, P., and L. Esibov, "A DNS RR for 2135 specifying the location of services (DNS SRV)", RFC 2782, 2136 DOI 10.17487/RFC2782, February 2000, 2137 . 2139 [RFC4026] Andersson, L. and T. Madsen, "Provider Provisioned Virtual 2140 Private Network (VPN) Terminology", RFC 4026, 2141 DOI 10.17487/RFC4026, March 2005, 2142 . 2144 [RFC4176] El Mghazli, Y., Ed., Nadeau, T., Boucadair, M., Chan, K., 2145 and A. Gonguet, "Framework for Layer 3 Virtual Private 2146 Networks (L3VPN) Operations and Management", RFC 4176, 2147 DOI 10.17487/RFC4176, October 2005, 2148 . 2150 [RFC6347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer 2151 Security Version 1.2", RFC 6347, DOI 10.17487/RFC6347, 2152 January 2012, . 2154 [RFC6462] Cooper, A., "Report from the Internet Privacy Workshop", 2155 RFC 6462, DOI 10.17487/RFC6462, January 2012, 2156 . 2158 [RFC6574] Tschofenig, H. and J. Arkko, "Report from the Smart Object 2159 Workshop", RFC 6574, DOI 10.17487/RFC6574, April 2012, 2160 . 2162 [RFC6770] Bertrand, G., Ed., Stephan, E., Burbridge, T., Eardley, 2163 P., Ma, K., and G. Watson, "Use Cases for Content Delivery 2164 Network Interconnection", RFC 6770, DOI 10.17487/RFC6770, 2165 November 2012, . 2167 [RFC6793] Vohra, Q. and E. Chen, "BGP Support for Four-Octet 2168 Autonomous System (AS) Number Space", RFC 6793, 2169 DOI 10.17487/RFC6793, December 2012, 2170 . 2172 [RFC6830] Farinacci, D., Fuller, V., Meyer, D., and D. Lewis, "The 2173 Locator/ID Separation Protocol (LISP)", RFC 6830, 2174 DOI 10.17487/RFC6830, January 2013, 2175 . 2177 [RFC6973] Cooper, A., Tschofenig, H., Aboba, B., Peterson, J., 2178 Morris, J., Hansen, M., and R. Smith, "Privacy 2179 Considerations for Internet Protocols", RFC 6973, 2180 DOI 10.17487/RFC6973, July 2013, 2181 . 2183 [RFC7149] Boucadair, M. and C. Jacquenet, "Software-Defined 2184 Networking: A Perspective from within a Service Provider 2185 Environment", RFC 7149, DOI 10.17487/RFC7149, March 2014, 2186 . 2188 [RFC7215] Jakab, L., Cabellos-Aparicio, A., Coras, F., Domingo- 2189 Pascual, J., and D. Lewis, "Locator/Identifier Separation 2190 Protocol (LISP) Network Element Deployment 2191 Considerations", RFC 7215, DOI 10.17487/RFC7215, April 2192 2014, . 2194 [RFC7297] Boucadair, M., Jacquenet, C., and N. Wang, "IP 2195 Connectivity Provisioning Profile (CPP)", RFC 7297, 2196 DOI 10.17487/RFC7297, July 2014, 2197 . 2199 Authors' Addresses 2200 Mohamed Boucadair 2201 Orange 2202 Rennes 35000 2203 France 2205 Email: mohamed.boucadair@orange.com 2207 Christian Jacquenet 2208 Orange 2209 Rennes 35000 2210 France 2212 Email: christian.jacquenet@orange.com 2214 Dacheng Zhang 2215 Huawei Technologies 2217 Email: zhangdacheng@huawei.com 2219 Panos Georgatsos 2220 Centre for Research and Innovation Hellas 2221 78, Filikis Etairias str. 2222 Volos, Hellas 38334 2223 Greece 2225 Phone: +302421306070 2226 Email: pgeorgat@iti.gr