idnits 2.17.1 draft-boucadair-connectivity-provisioning-protocol-13.txt: Checking boilerplate required by RFC 5378 and the IETF Trust (see https://trustee.ietf.org/license-info): ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/1id-guidelines.txt: ---------------------------------------------------------------------------- No issues found here. Checking nits according to https://www.ietf.org/id-info/checklist : ---------------------------------------------------------------------------- No issues found here. Miscellaneous warnings: ---------------------------------------------------------------------------- == The copyright year in the IETF Trust and authors Copyright Line does not match the current year -- The document date (December 8, 2016) is 2697 days in the past. Is this intentional? Checking references for intended status: Informational ---------------------------------------------------------------------------- == Outdated reference: A later version (-10) exists of draft-ietf-i2nsf-framework-04 -- Obsolete informational reference (is this intentional?): RFC 6347 (Obsoleted by RFC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 (~~), 2 warnings (==), 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: June 11, 2017 D. Zhang 6 Huawei Technologies 7 P. Georgatsos 8 CERTH 9 December 8, 2016 11 Connectivity Provisioning Negotiation Protocol (CPNP) 12 draft-boucadair-connectivity-provisioning-protocol-13 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 June 11, 2017. 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 . . . . . . . . . . . . . . . . . . . 11 73 8. Protocol Overview . . . . . . . . . . . . . . . . . . . . . . 13 74 8.1. Client/Server Communication . . . . . . . . . . . . . . . 13 75 8.2. Server Discovery . . . . . . . . . . . . . . . . . . . . 14 76 8.3. Policy Configuration on the CPNP Server . . . . . . . . . 14 77 8.4. CPNP Session . . . . . . . . . . . . . . . . . . . . . . 16 78 8.5. Extended CPNP Session . . . . . . . . . . . . . . . . . . 16 79 8.6. CPNP Transaction . . . . . . . . . . . . . . . . . . . . 16 80 8.7. CPNP Timers . . . . . . . . . . . . . . . . . . . . . . . 17 81 8.8. CPNP Operations . . . . . . . . . . . . . . . . . . . . . 17 82 8.9. Connectivity Provisioning Documents . . . . . . . . . . . 19 83 8.10. Child Provisioning Quotation Orders . . . . . . . . . . . 20 84 8.11. Negotiations with Multiple CPNP Servers . . . . . . . . . 21 85 8.12. State Management . . . . . . . . . . . . . . . . . . . . 21 86 8.12.1. On the Client Side . . . . . . . . . . . . . . . . . 22 87 8.12.2. On the Server Side . . . . . . . . . . . . . . . . . 24 88 9. CPNP Objects . . . . . . . . . . . . . . . . . . . . . . . . 26 89 9.1. Attributes . . . . . . . . . . . . . . . . . . . . . . . 26 90 9.1.1. CUSTOMER_AGREEMENT_IDENTIFIER . . . . . . . . . . . . 26 91 9.1.2. PROVIDER_AGREEMENT_IDENTIFIER . . . . . . . . . . . . 26 92 9.1.3. TRANSACTION_ID . . . . . . . . . . . . . . . . . . . 27 93 9.1.4. SEQUENCE_NUMBER . . . . . . . . . . . . . . . . . . . 27 94 9.1.5. NONCE . . . . . . . . . . . . . . . . . . . . . . . . 27 95 9.1.6. EXPECTED_RESPONSE_TIME . . . . . . . . . . . . . . . 27 96 9.1.7. EXPECTED_OFFER_TIME . . . . . . . . . . . . . . . . . 27 97 9.1.8. VALIDITY_OFFER_TIME . . . . . . . . . . . . . . . . . 28 98 9.1.9. CONNECTIVITY_PROVISIONING_DOCUMENT . . . . . . . . . 28 99 9.1.10. Information Elements . . . . . . . . . . . . . . . . 28 100 9.2. Operation Messages . . . . . . . . . . . . . . . . . . . 30 101 9.2.1. QUOTATION . . . . . . . . . . . . . . . . . . . . . . 30 102 9.2.2. PROCESSING . . . . . . . . . . . . . . . . . . . . . 30 103 9.2.3. OFFER . . . . . . . . . . . . . . . . . . . . . . . . 32 104 9.2.4. ACCEPT . . . . . . . . . . . . . . . . . . . . . . . 32 105 9.2.5. DECLINE . . . . . . . . . . . . . . . . . . . . . . . 33 106 9.2.6. ACK . . . . . . . . . . . . . . . . . . . . . . . . . 33 107 9.2.7. CANCEL . . . . . . . . . . . . . . . . . . . . . . . 34 108 9.2.8. WITHDRAW . . . . . . . . . . . . . . . . . . . . . . 35 109 9.2.9. UPDATE . . . . . . . . . . . . . . . . . . . . . . . 35 110 9.2.10. FAIL . . . . . . . . . . . . . . . . . . . . . . . . 37 111 10. Message Validation . . . . . . . . . . . . . . . . . . . . . 38 112 10.1. On the Client Side . . . . . . . . . . . . . . . . . . . 38 113 10.2. On the Server Side . . . . . . . . . . . . . . . . . . . 39 114 11. Theory of Operation . . . . . . . . . . . . . . . . . . . . . 39 115 11.1. Client Behavior . . . . . . . . . . . . . . . . . . . . 39 116 11.1.1. Order Negotiation Cycle . . . . . . . . . . . . . . 39 117 11.1.2. Order Withdrawal Cycle . . . . . . . . . . . . . . . 41 118 11.1.3. Order Update Cycle . . . . . . . . . . . . . . . . . 41 119 11.2. Server Behavior . . . . . . . . . . . . . . . . . . . . 42 120 11.2.1. Order Processing . . . . . . . . . . . . . . . . . . 42 121 11.2.2. Order Withdrawal . . . . . . . . . . . . . . . . . . 43 122 11.2.3. Order Update . . . . . . . . . . . . . . . . . . . . 43 123 11.3. Sequence Numbers . . . . . . . . . . . . . . . . . . . . 43 124 11.4. Message Re-Transmission . . . . . . . . . . . . . . . . 44 125 12. Operational Guidelines . . . . . . . . . . . . . . . . . . . 44 126 12.1. Logging on the CPNP Server . . . . . . . . . . . . . . . 44 127 12.2. Business Guidelines & Objectives . . . . . . . . . . . . 44 128 13. Security Considerations . . . . . . . . . . . . . . . . . . . 45 129 14. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 46 130 15. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 46 131 16. References . . . . . . . . . . . . . . . . . . . . . . . . . 46 132 16.1. Normative References . . . . . . . . . . . . . . . . . . 46 133 16.2. Informative References . . . . . . . . . . . . . . . . . 47 134 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 49 136 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]. A YANG data 363 model for L3VPN service delivery is defined in 364 [I-D.ietf-l3sm-l3vpn-service-model]. 366 2. CPNP can be used between two adjacent domains to deliver IP 367 interconnection services (e.g., enable, update, disconnect). 368 For example, two Autonomous Systems (ASes) can be connected via 369 several interconnection points. CPNP can be used between these 370 ASes to upgrade existing links, request additional resources, 371 provision a new interconnection point, etc. 373 See, for example, the framework documented in [ETICS]. 375 3. An integrated Provider can use CPNP to rationalize connectivity 376 provisioning needs related to its service portfolio. A CPNP 377 server function is used by network operations teams. A CPNP 378 interface to invoke CPNP negotiation cycles is exposed to 379 service management teams. 381 4. Service Providers can use CPNP to initiate connectivity 382 provisioning requests towards a number of Network Providers so 383 that to optimize the cost of delivering their services. 384 Although multiple CPNP ordering cycles can be initiated by a 385 Service Provider towards multiple Network Providers, a subset of 386 these orders may actually be put into effect. 388 For example, a cloud Service Provider can use CPNP to request 389 more resources from Network Providers. 391 5. CPNP can be used in Machine-to-Machine (M2M) environments to 392 dynamically subscribe to M2M services (e.g., access to data 393 retrieved by a set of sensors, extend sensor coverage, etc.). 395 Also, Internet of Things (IoT, [RFC6574]) domains may rely on 396 CPNP to enable dynamic provisioning of data produced by involved 397 objects, according to their specific policies, to various 398 external stakeholders such as data analytics and business 399 intelligence companies. Direct CPNP-based interactions between 400 IoT domains and interested parties enable open access to diverse 401 sets of data across the Internet, e.g., from multiple types of 402 sensors, user groups and/or geographical areas. 404 6. CPNP can be used in the context of I2NSF 405 ([I-D.ietf-i2nsf-framework]) to capture the customer-driven 406 policies to be enforced by a set of Network Security Functions. 408 7. A Provider offering cloud services can expose a CPNP interface 409 to allow Customers to dynamically negotiate related service 410 features such as additional storage, processing and networking 411 resources, enhanced security filters, etc. 413 8. In the inter-cloud context (also called cloud of clouds or cloud 414 federation), CPNP can be used to reserve external computing and 415 networking resources in other cloud environments. 417 9. CDN Providers can use CPNP to extend their footprint by 418 interconnecting their CDN infrastructure [RFC6770] (see 419 Figure 1). 421 ,--,--,--. ,--,--,--. 422 ,-' `-. ,-' `-. 423 (CDN Provider 'A')=====(CDN Provider 'B') 424 `-. (CDN-A) ,-' `-. (CDN-B) ,-' 425 `--'--'--' `--'--'--' 427 Figure 1: CDN Interconnection 429 10. Mapping Service Providers (MSPs, [RFC7215]) can use CPNP to 430 enrich their mapping database by interconnecting their mapping 431 system (see Figure 2). This interconnection allows to relax the 432 constraints on PxTR in favour of native LISP forwarding 433 [RFC6830]. Also, it allows to prevent fragmented LISP mapping 434 database. A framework is described in 435 [I-D.boucadair-lisp-idr-ms-discovery]. 437 ,--,--,--. ,--,--,--. 438 ,-' `-. ,-' `-. 439 (Mapping System 'A')===(Mapping System 'B') 440 `-. ,-' `-. ,-' 441 `--'--'--' `--'--'--' 443 Figure 2: LISP Mapping System Interconnect 445 6. CPNP Deployment Models 447 Several CPNP deployment models can be envisaged. Two examples are 448 listed below: 450 o The Customer deploys a CPNP client while one or several CPNP 451 servers are deployed by the Provider. 452 o The Customer does not enable any CPNP client. The Provider 453 maintains a Customer Order Management portal. The Customer can 454 initiate connectivity provisioning quotation orders via the 455 portal; appropriate CPNP messages are then generated and sent to 456 the relevant CPNP server. In this model, both the CPNP client and 457 CPNP server are under the responsibility of the same 458 administrative entity (i.e., Network Provider). 460 Once the negotiation of connectivity provisioning parameters is 461 successfully concluded that is, an order has been placed by the 462 Customer, the actual network provisioning operations are initiated. 463 The specification of related dynamic resource allocation and policy 464 enforcement schemes, as well as how CPNP servers interact with the 465 network provisioning functional blocks at Provider sides are out of 466 the scope of this document. 468 This document does not make any assumption about the CPNP deployment 469 model either. 471 7. CPNP Negotiation Model 473 CPNP runs between a Customer and a Provider carrying service orders 474 from the Customer and respective responses from the Provider to the 475 end of reaching a connectivity service provisioning agreement. As 476 the services offered by the Provider are well-described, by means of 477 the CPP template, the negotiation process is essentially a value- 478 settlement process, where an agreement is pursued on the values of 479 the commonly understood information items (service parameters) 480 included in the service description template. 482 The protocol is transparent to the content that it carries and to the 483 negotiation logic, at Customer and Provider sides, that manipulates 484 the content. 486 The protocol aims at facilitating the execution of the negotiation 487 logic by providing the required generic communication primitives. 489 Since negotiations are initiated and primarily driven by the 490 Customer's negotiation logic, it is reasonable to assume that the 491 Customer can only call for an agreement. An implicit approach is 492 adopted for not overloading the protocol with additional messages. 493 In particular, the acceptance of an offer made by the Provider 494 signals a call for agreement from the Customer. Note that it is 495 almost certain the Provider to accept this call since it refers to an 496 offer that itself made. Of course, at any point the Provider or the 497 Customer may quit the negotiations, each on its own grounds. 499 Based on the above, CPNP adopts a Quotation Order/Offer/Answer model, 500 which proceeds through the following basic steps: 502 1. The client specifies its service requirements via a Provision 503 Quotation Order (PQO). The order may include fixed or loosely 504 defined values in the clauses describing service provisioning 505 characteristics. 507 2. The server declines the PQO, or makes an offer to address the 508 requirements of the PQO, or which may suggests a counter- 509 proposals that partially addresses the requirements of the PQO 510 for specific requirements that cannot be accommodated. 512 3. The client either accepts or declines the offer. Accepting the 513 offer implies a call for agreement. 515 Multiple instances of CPNP may run at Customer or Provider domains. 516 A CPNP client may be engaged simultaneously in multiple negotiations 517 with the same or different CPNP servers (parallel negotiations, see 518 Section 8.11) and a CPNP server may need to negotiate with other 519 Provider(s) as part of negotiations with a CPNP client (cascaded 520 negotiations, see Section 8.10). 522 CPNP relies on various timers to achieve its operations. These 523 timers are used to guide the negotiation logic at both CPNP client 524 and CPNP server sides, particularly in cases where the CPNP client is 525 involved in parallel negotiations with several CPNP servers or in 526 cases where the CPNP server is, in its turn, involved in negotiations 527 with other Providers for processing a given quotation order. Related 528 to the above, CPNP allows the CPNP server to request for more time. 529 This request may be accepted or rejected by the CPNP client. 531 Providers may need to publish available services to the Customers 532 (see Section 4). CPNP may optionally support this functionality. 533 Dedicated templates can be defined for the purpose of service 534 announcements, which will be used by the CPNP clients to initiate 535 their CPNP negotiation cycles. 537 For simplicity, a single Offer/Answer stage is assumed within one a 538 CPNP negotiation cycle. Nevertheless, as stated before, multiple 539 CPNP negotiation cycles can be undertaken by a CPNP client (see 540 Figure 3). 542 The model is flexible as it can accommodate changing conditions over 543 time (e.g., introduction of an additional VPN site). 545 +------+ +------+ +------+ +------+ 546 |Client| |Server| |Client| |Server| 547 +------+ +------+ +------+ +------+ 548 |=====Quotation Order=====>| |=====Quotation Order=====>| 549 |<==========Offer==========| |<==========Offer==========| 550 |===========Accept========>| |==========Decline========>| 552 1-Step Successful Negotiation 1-Step Failed Negotiation 553 Cycle Cycle 555 +------+ +------+ +------+ +------+ 556 |Client| |Server| |Client| |Server| 557 +------+ +------+ +------+ +------+ 558 |===Quotation Order(a)====>| |===Quotation Order(i)====>| 559 |<==========Offer==========| |<==========Offer==========| 560 |==========Decline========>| |==========Decline========>| 561 |===Quotation Order(b)====>| |===Quotation Order(j)====>| 562 |<==========Offer==========| |<==========Offer==========| 563 |===========Accept========>| |==========Decline========>| 564 |===Quotation Order(k)====>| 565 |<==========Offer==========| 566 |==========Decline========>| 567 |===Quotation Order(l)====>| 568 |<==Fail to make an offer==| 570 N-Step Negotiation Cycle: N-Step Negotiation Cycle: 571 Successful Negotiation Failed Negotiation 573 Figure 3: Overall Negotiation Process 575 8. Protocol Overview 577 8.1. Client/Server Communication 579 CPNP is a client/server protocol which is designed to run over any 580 transport protocol with UDP being the default transport mode. No 581 permanent CPNP session needs to be maintained between the client and 582 the server. There is no need to run CPNP over a reliable transport 583 mode because CPNP messages are acknowledged. 585 The server advertises the port (CPNP_PORT) it uses to bind the CPNP 586 service (e.g., using SRV [RFC2782]). The client sends CPNP messages 587 to CPNP_PORT; this port is discovered as per Section 8.2. The same 588 port used as the source port of the request sent to the server MUST 589 be used by the server to reply to that request. 591 CPNP is independent of the IP address family. 593 CPNP retransmission is discussed in Section 11.4. 595 8.2. Server Discovery 597 The CPNP client can be configured with the CPNP server(s) (typically, 598 an IP address together with a port number) using manual or dynamic 599 configuration means. For example, Providers may configure dedicated 600 SRV records or may use a well-known name/address. 602 Discussions about how the client can discovers its the server(s) of 603 its interest are out of the scope of this document. The document 604 assumes that a the required CPNP server can be reached by the CPNP 605 client, thanks to some configuration means. 607 8.3. Policy Configuration on the CPNP Server 609 As an input to its decision-making process, the CPNP server may be 610 connected to various external modules such as: Customer Profiles, 611 Network Topology, Network Resource Management, Orders Repository, AAA 612 and Network Provisioning Manager (an example is shown in Figure 4). 614 These external modules provide inputs to the CPNP server, so that it 615 can: 617 o Check whether a customer is entitled to initiate a provisioning 618 quotation request. 620 o Check whether a customer is entitled to cancel an on-going order. 622 o Check whether administrative data (e.g., billing-related 623 information) have been verified before starting handling the 624 request. 626 o Check whether network capacity is available or additional capacity 627 is required. 629 o Receive guidelines from network design and sales blocks (e.g., 630 pricing, network usage levels, threshold on number of CPP 631 templates that can be processed over a given period of time as a 632 function of the nature of the service to be delivered, etc.). 634 o Transfer completed orders to network provisioning blocks. 636 The above list of CPNP server operations is not exhaustive. 638 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 639 .Business & Administrative Management . 640 .+------------------------++---------------------------+. 641 .| Business Guidelines || Billing & Charging |. 642 .+-----------+------------++-----------+---------------+. 643 . | | . 644 . +-------------------+ | . 645 . . . . . . . . . . . . . . . . .|. . .|. . . . . . . . . 646 . . . . . . . . . . . . . . . . .|. . .|. . . . . . . . . 647 .Order Handling Management | | . 648 . +-------------------+ +-------+-----+--------------+ . 649 . |Network Topology DB+--+ CPNP Server | . 650 . +-------------------+ +-+---+---+---+---+-----+----+ . 651 . | | | | | | . 652 . +------------------------+-+ | | | | | . 653 . | Network Dimensioning | | | | | | . 654 . | & Planning | | | | | | . 655 . +--------------------------+ | | | | | . 656 . +----------------------------+-+ | | | +---+----+ . 657 . | | | | | | AAA | . 658 . | Network +------------+ | | | +--------+ . 659 . | Resource | +------------+-+ | +-+----------+ . 660 . | Management | | Customer | | | Orders | . 661 . | | | Profiles | | | Repository | . 662 . +-----------------+ +--------------+ | +------------+ . 663 . . . . . . . . . . . . . . . . . . . .|. . . . . . . . . 664 +--------------------------------------+----------------+ 665 | Network Provisioning Manager | 666 +-------------------------------------------------------+ 668 Figure 4: Order Handling Management Functional Block 670 The following order handling modes can be also configured on the 671 server: 673 1. Fully automated mode: This mode does not require any action from 674 the administrator when receiving a request for a service. The 675 server can execute its decision-making process related to the 676 orders received and generate corresponding offers. 677 2. Administrative validation checking: Some or all of the server's 678 operations are subject to administrative validation procedures. 679 This mode requires an action from the administrator for every 680 request received. The CPNP methods which can be automatically 681 handled by the server or they are subject to one or several 682 validation administrative checks can be configured on the server. 684 8.4. CPNP Session 686 Both the client and server maintain the following CPNP transport 687 session information: 689 A CPNP session is identified by the following items: 691 o IP address of the client 692 o Client's port number 693 o IP address of the server 694 o Server's port number 696 8.5. Extended CPNP Session 698 An extended PQO session is denoted by a 5-uplet defined as follows: 700 o CPNP session (Section 8.4) 702 o Incremented Sequence Number (Section 11.3) 704 o Customer Agreement Identifier: This is a unique identifier 705 assigned to the order under negotiation by the client 706 (Section 9.1.1). This identifier is also used to identify the 707 agreement that will result from a successful negotiation. 709 o Provider Agreement Identifier: This is a unique identifier 710 assigned to the order under negotiation by the server 711 (Section 9.1.2). This identifier is also used to identify the 712 agreement that will result from a successful negotiation. 714 o Transaction-ID (Section 9.1.3) 716 8.6. CPNP Transaction 718 A CPNP transaction occurs between a client and a server for pursuing, 719 modifying, withdrawing a service agreement and comprises all CPNP 720 messages exchanged between the client and the server, from the first 721 request sent by the client to the final response sent by the server. 722 A CPNP transaction is bound to a CPNP session. 724 Because multiple CPNP transactions can be maintained by the CPNP 725 client, the client must assign an identifier to uniquely identify a 726 given transaction. This identifier is denoted as Transaction-ID. 728 The Transaction-ID must be randomly assigned by the CPNP client, 729 according to the best current practice for generating random numbers 730 [RFC4086] that cannot be guessed easily. Transaction-ID is used for 731 validating CPNP responses received by the client. 733 In the context of a transaction, the client needs to randomly select 734 a sequence number and assign it in the first CPNP message to send. 735 This number is then incremented for each request message is 736 subsequently sent within the on-going CPNP transaction (see 737 Section 11.3). 739 8.7. CPNP Timers 741 CPNP adopts a simple retransmission procedure which relies on a 742 retransmission timer denoted as RETRANS_TIMER and maximum retry 743 threshold. The use of RETRANS_TIMER and a maximum retry threshold 744 are described in Section 11. 746 The response timer (RESPONSE_TIMER) is set by the client to denote 747 the time, in seconds, the client will wait for receiving a response 748 from the server to a provisioning quotation order request (see 749 Section 9.1.6). If the timer expires, the respective quotation order 750 is cancelled by the client and a CANCEL message is generated 751 accordingly. 753 An offer expiration timer (EXPIRE_TIMER) is set by the server to 754 represent the time, in minutes, after which an offer made by the 755 server will be invalid (see Section 9.1.8). 757 8.8. CPNP Operations 759 The current CPNP operations are listed below. They may be augmented, 760 depending on the nature of some transactions or because of security 761 considerations that may necessitate a distinct CPNP client/server 762 authentication phase before negotiation begins. 764 o QUOTATION (Section 9.2.1): 766 This operation is used by the client to initiate a provisioning 767 quotation order. Upon receipt of a QUOTATION request, the server 768 may respond with a PROCESSING, OFFER or a FAIL message. A 769 QUOTATION-initiated transaction can be terminated by a FAIL 770 message. 772 o PROCESSING (Section 9.2.2): 774 This operation is used to inform the remote party that the message 775 (the order quotation or the offer) sent was received and it is 776 processed. This message can also be issued by the server to 777 request more time, in which case the client may reply with an ACK 778 or FAIL message depending on whether more time can or cannot be 779 granted. 781 o OFFER (Section 9.2.3): 783 This operation is used by the server to inform the client about an 784 offer that can best accommodate the requirements indicated in the 785 previously received QUOTATION message. 787 o ACCEPT (Section 9.2.4): 789 This operation is used by the client to confirm the acceptance of 790 an offer made by the server. This message implies a call for 791 agreement. An agreement is reached when an ACK is subsequently 792 received from the server, which is likely to happen; it is rather 793 unlikely the server to reject an offer that it has already made. 795 o DECLINE (Section 9.2.5): 797 This operation is used by the client to reject an offer made by 798 the server. The on-going transaction may not be terminated 799 immediately, e.g., the server/client may issue another offer/ 800 order. 802 o ACK (Section 9.2.6): 804 This operation is used by the server to acknowledge the receipt of 805 an ACCEPT or WITHDRAW message, or by the client to confirm the 806 time extension requested by the server for processing the last 807 received quotation order. 809 o CANCEL (Section 9.2.7): 811 This operation is used by the client to cancel (quit) the on-going 812 transaction. 814 o WITHDRAW (Section 9.2.8): 816 This operation is used by the client to withdraw an agreement. 818 o UPDATE (Section 9.2.9): 820 This operation is used by the client to update an existing 821 agreement. For example, this method can be invoked to add a new 822 site. This method will trigger a new negotiation cycle. 824 o FAIL (Section 9.2.10): 826 This operation is used by the server to indicate that it cannot 827 accommodate the requirements documented in the PQO conveyed in the 828 QUOTATION message or to inform the client about an error 829 encountered when processing the received message. In either case, 830 the message implies that the server is unable to make offers and 831 as such it terminates the on-going transaction. 833 This message is also used by the client to reject a time extension 834 request received from the server (in a PROCESSING message). The 835 message includes a status code for providing explanatory 836 information. 838 The above CPNP primitives are service-independent. CPNP messages may 839 transparently carry service-specific objects which are handled by the 840 negotiation logic at either side. 842 The document specifies the service objects that are required for 843 connectivity provisioning negotiation (see Section 8.9). Additional 844 service-specific objects to be carried in the CPNP messages can be 845 defined in the future for accommodating alternative deployment or 846 other service provisioning needs. 848 8.9. Connectivity Provisioning Documents 850 CPNP makes use of several flavors of Connectivity Provisioning 851 Documents (CPD). These documents follow the CPP template described 852 in [RFC7297]. 854 Requested Connectivity Provisioning Document (Requested CPD): 855 Refers to the CPD included by a CPNP client in a QUOTATION 856 request. 858 Offered Connectivity Provisioning Document (Offered CPD): This 859 document is included by a CPNP server in an OFFER message. Its 860 information reflects the proposal of the server to accommodate all 861 or a subset of the clauses depicted in a Requested CPD. A 862 validity time is associated with the offer made. 864 Agreed Connectivity Provisioning Document (Agreed CPD): If the 865 client accepts an offer made by the server, the Offered CPD is 866 included in an ACCEPT message. This CPD is also included in an 867 ACK message. Thus, a 3-way hand-shaking procedure is followed for 868 successfully concluding the negotiation. 870 Figure 5 shows a typical CPNP negotiation cycle and the use of the 871 different types of Connectivity Provisioning Documents. 873 +------+ +------+ 874 |Client| |Server| 875 +------+ +------+ 876 |======QUOTATION (Requested CPD)=====>| 877 |<============PROCESSING==============| 878 |<========OFFER (Offered CPD)=========| 879 |=============PROCESSING=============>| 880 |=========ACCEPT (Agreed CPD)========>| 881 |<=========ACK (Agreed CPD)===========| 882 | | 884 Figure 5: Connectivity Provisioning Documents 886 A provisioning document can include parameters with fixed values, 887 loosely defined values, or a combination thereof. A provisioning 888 document is said to be concrete if all clauses have fixed values. 890 A typical evolution of a negotiation cycle would start with a 891 quotation order with loosely defined parameters, and then, as offers 892 are made, it would conclude with concrete provisioning document for 893 calling for the agreement. 895 8.10. Child Provisioning Quotation Orders 897 If the server detects that network resources from another Network 898 Provider need to be allocated in order to accommodate the 899 requirements described in a PQO (e.g., in the context of an inter- 900 domain VPN service, additional PE router resources need to be 901 allocated), the server may generate child PQOs to request the 902 appropriate network provisioning operations (see Figure 6). In such 903 situation, the server behaves also as a CPNP client. The server 904 associates the parent order with its child PQOs. This is typically 905 achieved by locally adding the reference of the child PQO to the 906 parent order. 908 +------+ +--------+ +--------+ 909 |Client| |Server A| |Server B| 910 +------+ +--------+ +--------+ 911 | | | 912 |=====QUOTATION=====>| | 913 |<====PROCESSING=====| | 914 | |=====QUOTATION=====>| 915 | |<====PROCESSING=====| 916 | |<=======OFFER=======| 917 | |=====PROCESSING====>| 918 | |=======ACCEPT======>| 919 | |<=======ACK=========| 920 |<=======OFFER=======| | 921 |=====PROCESSING====>| | 922 |=======ACCEPT======>| | 923 |<=======ACK=========| | 924 | | | 926 Figure 6: Example of Child Orders 928 8.11. Negotiations with Multiple CPNP Servers 930 A CPNP client may undertake multiple negotiations in parallel with 931 several servers for practical reasons such as cost optimization and 932 fail-safety. The multiple negotiations may lead to one or many 933 agreements. Multiple negotiations with the same Provider are not 934 precluded. 936 The salient point underlining the parallel negotiations scenario is 937 that although the negotiation protocol is strictly between two 938 parties, the negotiation logic may not necessarily be. The CPNP 939 client negotiation logic may need to collectively drive parallel 940 negotiations, as the negotiation with one server may affect the 941 negotiation with other servers; e.g., it may need to use the 942 responses from all servers as input for determining the messages (and 943 their content) to subsequently send in each individual negotiation. 944 Timing is therefore an important aspect at the client's. The CPNP 945 client needs to have the ability to synchronize the receipt of the 946 responses from the servers. CPNP takes into account this requirement 947 by allowing clients to specify in the QUOTATION message the time by 948 which the server needs to respond (see Section 9.1.6). 950 8.12. State Management 952 Both the client and the server maintain repositories to store on- 953 going orders. How these repositories are maintained is deployment- 954 specific. It is out of scope of this document to elaborate on such 955 considerations. Timestamps are also logged to track state change. 956 Tracking may be needed for various reasons,including regulatory ones. 958 8.12.1. On the Client Side 960 The following lists the states which can be associated with a given 961 order on the client's side: 963 o Created: when the order has been created. It is not handled by 964 the client until the administrator allows to process it. 966 o AwaitingProcessing: when the administrator approved of processing 967 a created order and the order has not been handled yet. 969 o PQOSent: when the order has been sent to the server. 971 o ServerProcessing: when the server has confirmed the receipt of the 972 order. 974 o OfferReceived: when an offer has been received from the server. 976 o OfferProcessing: when a received offer is currently processed by 977 the client. 979 o AcceptSent: when the client confirmed the offer to the server. 981 o AcceptAck: when the offer is acknowledged by the server. 983 o Cancelled: when the order has failed or cancelled. 985 +------------------+ 986 | Created |-----------------+ 987 +------------------+ | 988 | | 989 v | 990 +------------------+ | 991 |AwaitingProcessing|----------------+| 992 +------------------+ || 993 | || 994 QUOTATION || 995 v || 996 +------------------+ || 997 | PQOSent |---CANCEL------+|| 998 +------------------+ vvv 999 | +-----+ 1000 PROCESSING | | 1001 v | | 1002 +------------------+ CANCEL | C | 1003 | ServerProcessing |------------>| A | 1004 +------------------+ FAIL | N | 1005 | | C | 1006 | | E | 1007 OFFER | L | 1008 | | L | 1009 v | E | 1010 +------------------+ | D | 1011 | OfferReceived |---CANCEL--->| | 1012 +------------------+ | | 1013 | PROCESSING +-----+ 1014 v ^^^ 1015 +------------------+ ||| 1016 | OfferProcessing |---DECLINE-----+|| 1017 +------------------+ || 1018 | ACCEPT || 1019 v || 1020 +------------------+ || 1021 | AcceptSent |---CANCEL-------+| 1022 +------------------+ | 1023 | ACK | 1024 v | 1025 +------------------+ | 1026 | AcceptAck |---WITHDRAW------+ 1027 +------------------+ 1029 Figure 7: CPNP Finite State Machine (Client Side) 1031 8.12.2. On the Server Side 1033 The following lists the states which can be associated with a given 1034 order and a corresponding offer on the server's side: 1036 o PQOReceived: when the order has been received from the client. 1038 o AwaitingProcessing: when the order is being processed by the 1039 server. An action from the server administrator may be needed. 1041 o OfferProposed: when the request has been successfully handled and 1042 an offer has been sent to the client. 1044 o ProcessingReceived: when the server received a PROCESSING for an 1045 offer sent to the client. 1047 o AcceptReceived: when the server received a confirmation for the 1048 offer from the client. 1050 o AcceptAck: when the server acknowledged the offer (accepted by 1051 client) to the client. 1053 o Cancelled: when the order has failed to be met or it has been 1054 cancelled by the client. Associate resources must be released in 1055 the latter case, if prior reserved. 1057 o ChildCreated: when a child order has been created in cases where 1058 resources from another Network Provider are needed. 1060 o ChildPQOSent: when a child order has been sent to the remote 1061 server. 1063 o ChildServerProcessing: when a child order is currently processed 1064 by the remote server. 1066 o ChildOfferReceived: when an offer has been received to a child 1067 order from the remote server. 1069 o ChildOfferProcessing: when a received offer to a child order is 1070 currently processed. 1072 o ChildAcceptSent: when the child offer (offer received from the 1073 remote server in response to a child order) is confirmed to the 1074 remote server. 1076 o ChildAcceptAck: when an accepted child offer is acknowledged by 1077 the remote server. 1079 +------------------+ 1080 +---------------------| ChildCreated | 1081 | +------------------+ 1082 v | ^ 1083 +------------------+ | | 1084 | ChildPQOSent |----------------+| Q 1085 +------------------+ || U 1086 | || O 1087 QUOTATION || T 1088 v || A +--------------------+ 1089 +---------------------+ CANCEL || T | PQOReceived | 1090 |ChildServerProcessing|------------+|| I +--------------------+ 1091 +---------------------+ FAIL vvv O | | 1092 | +-----+ N CANCEL | 1093 PROCESSING | |<---|-------+ PROCESSING 1094 v | | | v 1095 +------------------+ | | +------------------------+ 1096 |ChildOfferReceived|----CANCEL---| C |<--| AwaitingProcessing | 1097 +------------------+ | A | +------------------------+ 1098 | | N | ^ | OFFER 1099 OFFER | C | | +------------------+ 1100 | | E | ::= 1239 ... 1240 ::= 1241 ... 1242 ::= 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 ::= ... 1257 ::= 1258 1259 1261 Figure 9: The RBNF format of the Connectivity Provisioning Document 1262 (CPD) 1264 9.1.10. Information Elements 1266 An Information Element (IE) is an optional object which can be 1267 included in a CPNP message. 1269 9.1.10.1. Customer Description 1271 The client may include administrative information such as: 1273 o Name 1274 o Contact Information 1276 The format of this Information Element is as follows: 1278 ::= 1279 ::= [] 1280 [ ...] 1282 9.1.10.2. Provider Description 1284 The server may include administrative information in an offer such 1285 as: 1287 o Name 1288 o AS Number ([RFC6793]) 1289 o Contact Information 1291 The format of this Information Element is as follows: 1293 ::= [] 1295 9.1.10.3. Negotiation Options 1297 The client may include some negotiation options such as: 1299 o Cost: the client may include an empty or a preferred COST 1300 attribute to request the cost from the server. The server will 1301 provide the cost information in the response. 1302 o Setup purpose: A client may request to setup a connectivity only 1303 for testing purposes during a limited period. The order can be 1304 extended to become permanent if the client was satisfied during 1305 the test period. This operation is achieved using UPDATE method. 1307 Other negotiation options may be defined in the future. 1309 The format of this Information Element is as follows: 1311 ::= [][] 1313 9.2. Operation Messages 1315 This section specifies the RBNF format of CPNP operation messages. 1316 The following operation codes are used: 1318 1: QUOTATION (Section 9.2.1) 1319 2: PROCESSING (Section 9.2.2) 1320 3: OFFER (Section 9.2.3) 1321 4: ACCEPT (Section 9.2.4) 1322 5: DECLINE (Section 9.2.5) 1323 6: ACK (Section 9.2.6) 1324 7: CANCEL (Section 9.2.7) 1325 8: WITHDRAW (Section 9.2.8) 1326 9: UPDATE (Section 9.2.9) 1327 10: FAIL (Section 9.2.10) 1329 9.2.1. QUOTATION 1331 The format of the QUOTATION message is shown below: 1333 ::= 1334 1335 1336 1337 1338 [] 1339 1340 [...] 1342 A QUOTATION message must include an order identifier which is 1343 generated by the client. Because several orders can be issued to 1344 several servers, the QUOTATION message must also include a 1345 Transaction-ID. 1347 The message may include an EXPECTED_RESPONSE_TIME which indicates by 1348 when the client is expecting to receive an offer from the server. 1349 QUOTATION message must also include a requested connectivity 1350 provisioning document. 1352 When the client sends the QUOTATION message to the server, the state 1353 of the order changes to "PQOSent". 1355 9.2.2. PROCESSING 1357 The format of the PROCESSING message is shown below: 1359 ::= 1360 1361 1362 1363 1364 1365 [] 1367 Upon receipt of a QUOTATION message, the server proceeds with parsing 1368 rules (see Section 10). If no error is encountered, the server 1369 generates a PROCESSING response to the client to indicate the PQO has 1370 been received and it is being processed. The server must generate an 1371 order identifier which identifies the order in its local order 1372 repository. The server MUST copy the content of 1373 CUSTOMER_AGREEMENT_IDENTIFIER and TRANSACTION_ID fields as conveyed 1374 in the QUOTATION message. The server may include an 1375 EXPECTED_OFFER_TIME by when it expects to make an offer to the 1376 client. 1378 Upon receipt of a PROCESSING message, the client verifies whether it 1379 has issued a PQO to that server and which contains the 1380 CUSTOMER_AGREEMENT_IDENTIFIER and TRANSACTION_ID. If no such PQO is 1381 found, the PROCESSING message is silently ignored. If a PQO is 1382 found, the client may check if it accepts the EXPECTED_OFFER_TIME and 1383 then, it changes to state of the order to "ServerProcessing". 1385 If more time is required by the server to process the quotation 1386 order, it may send a PROCESSING message that includes a new 1387 EXPECTED_OFFER_TIME. The client can answer with an ACK message if 1388 more time is granted (Figure 10) or with a FAIL message if the time 1389 extension is rejected (Figure 11). 1391 +------+ +------+ 1392 |Client| |Server| 1393 +------+ +------+ 1394 |=======QUOTATION(Requested CPD)=====>| 1395 |<========PROCESSING(time1)===========| 1396 ... 1397 |<========PROCESSING(MoreTime)========| 1398 |============ACK(TimeGranted)========>| 1399 ... 1400 |<=========OFFER(Offered CPD)=========| 1401 |=============PROCESSING=============>| 1402 |==========ACCEPT(Agreed CPD)========>| 1403 |<==========ACK(Agreed CPD)===========| 1404 | | 1406 Figure 10: Request more negotiation time: Granted 1407 +------+ +------+ 1408 |Client| |Server| 1409 +------+ +------+ 1410 |=======QUOTATION(Requested CPD)=====>| 1411 |<========PROCESSING(time1)===========| 1412 ... 1413 |<========PROCESSING(MoreTime)========| 1414 |===========FAIL(TimeRejected)=======>| 1416 Figure 11: Request more negotiation time: Rejected 1418 9.2.3. OFFER 1420 The format of the OFFER message is shown below: 1422 ::= 1423 1424 1425 1426 1427 1428 1429 1430 1431 [...] 1433 The server answers with an OFFER message to a QUOTATION request 1434 received from the client. The offer will be considered as rejected 1435 by the client if no confirmation (ACCEPT message sent by the client) 1436 is received by the server before the expiration of the validity time. 1438 9.2.4. ACCEPT 1440 The format of the ACCEPT message is shown below: 1442 ::= 1443 1444 1445 1446 1447 1448 1449 1450 [...] 1452 This message is used by a client to confirm the acceptance of an 1453 offer received from a server. The fields of this message are copied 1454 from the received OFFER message. 1456 9.2.5. DECLINE 1458 The format of the DECLINE message is shown below: 1460 ::= 1461 1462 1463 1464 1465 1466 1468 The client can issue a DECLINE message to reject an offer. 1469 CUSTOMER_AGREEMENT_IDENTIFIER, PROVIDER_AGREEMENT_IDENTIFIER, 1470 TRANSACTION_ID, and NONCE are used by the server as keys to find the 1471 corresponding order. If an order matches, the server changes the 1472 state of this order to "Cancelled" and then returns an ACK with a 1473 copy of the requested CPD to the requesting client. 1475 If no order is found, the server returns a FAIL message to the 1476 requesting client. 1478 A flow example is shown in Figure 12. 1480 +------+ +------+ 1481 |Client| |Server| 1482 +------+ +------+ 1483 |=======QUOTATION(Requested CPD)=====>| 1484 |<============PROCESSING==============| 1485 |<=========OFFER(Offered CPD)=========| 1486 |=============PROCESSING=============>| 1487 |===============DECLINE==============>| 1488 |<================ACK=================| 1489 | | 1491 Figure 12: DECLINE Flow Example 1493 9.2.6. ACK 1495 The format of the ACK message is shown below: 1497 ::= 1498 1499 1500 1501 1502 1503 [] 1505 [] 1506 [...] 1508 This message is issued by the server to close a CPNP transaction or 1509 by a client to grant more negotiation time to the server. 1511 This message is sent by the server as a response to an ACCEPT, 1512 WITHDRAW, DECLINE, or CANCEL message. In such case, the ACK message 1513 must include the copy of the Connectivity Provisioning Document as 1514 stored by the server, in particular: 1516 o A copy of the requested/offered CPD is included by the server if 1517 it successfully handled a CANCEL message. 1518 o A copy of the updated CPD is included by the server if it 1519 successfully handled an UPDATE message. 1520 o A copy of the offered CPD is included by the server if it 1521 successfully handled an ACCEPT message in the context of a 1522 QUOTATION transaction. 1523 o An empty CPD is included by the server if it successfully handled 1524 a DECLINE message. 1526 A client may issue an ACK message as a response to a more time 1527 request (conveyed in PROCESSING) received from the server. In such 1528 case, the ACK message must include an EXPECTED_RESPONSE_TIME that is 1529 likely to be set to the time extension requested by the server. 1531 9.2.7. CANCEL 1533 The format of the CANCEL message is shown below: 1535 ::= 1536 1537 1538 1539 1540 [] 1542 The client can issue a CANCEL message at any stage during the CPNP 1543 negotiation process before an agreement is reached. 1544 CUSTOMER_AGREEMENT_IDENTIFIER and TRANSACTION_ID are used by the 1545 server as keys to find the corresponding order. If a quotation order 1546 matches, the server changes the state of this quotation order to 1547 "Cancelled" and then returns an ACK with a copy of the requested CPD 1548 to the requesting client. 1550 If no quotation order is found, the server returns a FAIL message to 1551 the requesting client. 1553 9.2.8. WITHDRAW 1555 The format of the WITHDRAW message is shown below: 1557 ::= 1558 1559 1560 1561 1562 1563 1564 [] 1565 [...] 1567 This message is used to withdraw an offer already subscribed by the 1568 Customer. Figure 13 shows a typical usage of this message. 1570 +------+ +------+ 1571 |Client| |Server| 1572 +------+ +------+ 1573 |============WITHDRAW(CPD)===========>| 1574 |<============PROCESSING==============| 1575 |<===========ACK(Empty CPD)===========| 1576 | | 1578 Figure 13: WITHDRAW Flow Example 1580 The CPNP must include the same CUSTOMER_AGREEMENT_IDENTIFIER, 1581 PROVIDER_AGREEMENT_IDENTIFIER, and NONCE as those used when creating 1582 the order. 1584 Upon receipt of a WITHDRAW message, the server checks whether an 1585 order matching the request is found. If an order is found, the state 1586 of the order is changed to "Cancelled" and an ACK message including 1587 an Empty CPD is returned to the requesting client. If no order is 1588 found, the server returns a FAIL message to the requesting client. 1590 9.2.9. UPDATE 1592 The format of the UPDATE message is shown below: 1594 ::= 1595 1596 1597 1598 1599 1600 1601 1602 1603 [...] 1605 This message is sent by the CPNP client to update an existing 1606 connectivity provisioning agreement. The CPNP must include the same 1607 CUSTOMER_AGREEMENT_IDENTIFIER, PROVIDER_AGREEMENT_IDENTIFIER, and 1608 NONCE as those used when creating the order. The CPNP client 1609 includes a new CPD which integrates the requested modifications. A 1610 new Transaction_ID must be assigned by the client. 1612 Upon receipt of an UPDATE message, the server checks whether an 1613 order, having state "Completed", matches 1614 CUSTOMER_AGREEMENT_IDENTIFIER, PROVIDER_AGREEMENT_IDENTIFIER, and 1615 NONCE. 1617 o If no order is found, the CPNP server generates a FAIL error with 1618 the appropriate error code. 1619 o If an order is found, the server checks whether it can honor the 1620 request: 1622 * A FAIL message is sent to the client if the server cannot honor 1623 the request. The client may initiate a new PQO negotiation 1624 cycle. 1625 * An OFFER message including the updated connectivity 1626 provisioning document is sent to the client. For example, the 1627 server maintains an order for provisioning a VPN service that 1628 connects sites A, B and C. If the client sends an UPDATE 1629 message to remove site C, only sites A and B will be included 1630 in the OFFER sent by the server to the requesting client. 1632 A flow chart that illustrates the use of UPDATE operation is shown in 1633 Figure 14. 1635 +------+ +------+ 1636 |Client| |Server| 1637 +------+ +------+ 1638 |=========UPDATE(Requested CPD)======>| 1639 |<============PROCESSING==============| 1640 |<=========OFFER(Updated CPD)=========| 1641 |=============PROCESSING=============>| 1642 |==========ACCEPT(Updated CPD)=======>| 1643 |<==========ACK(Updated CPD)==========| 1644 | | 1646 Figure 14: UPDATE Flow Example 1648 9.2.10. FAIL 1650 The format of the FAIL message is shown below: 1652 ::= 1653 1654 1655 1656 1657 1658 1660 This message is sent in the following cases: 1662 o The server can not honor an order received from the client (i.e., 1663 received in a QUOTATION or UPDATE request). 1664 o The server encounters an error when processing a CPNP request 1665 received from the client. 1666 o The client can not grant more time to a the server. This is a 1667 response to a more time request conveyed in a PROCESSING message. 1669 The status code indicates the error code. The following codes are 1670 supported: 1672 1 (Message Validation Error): 1673 The message can not be validated (see Section 10). 1674 2 (Authentication Required): 1675 The request cannot be handled because authentication is 1676 required. 1677 3 (Authorization Failed): 1678 The request cannot be handled because authorization failed. 1679 4 (Administratively prohibited): 1680 The request can not be handled because of administrative 1681 policies. 1682 5 (Out of Resources): 1683 The request can not be honored because there is not enough 1684 capacity. 1685 6 (Network Presence Error): 1686 The request can not be honored because there is no network 1687 presence. 1688 7 (More Time Rejected): 1689 The request to extend the time negotiation is rejected by the 1690 client. 1692 10. Message Validation 1694 Both client and server proceed with CPNP message validation. The 1695 following tables summarize the validation checks to be followed. 1697 10.1. On the Client Side 1699 Operation Validation Checks 1700 ------------ -------------------------------------------------------- 1701 PROCESSING {Source IP address, source port, destination IP address, 1702 destination port, Transaction-ID, Customer Order 1703 Identifier} must match an existing PQO with a state set 1704 to "PQOSent". The sequence number carried in the packet 1705 must be larger than the sequence number maintained by 1706 the client. 1707 OFFER {Source IP address, source port, destination IP address, 1708 destination port, Transaction-ID, Customer Order 1709 Identifier} must match an existing order with state set 1710 to "PQOSent" or {Source IP address, source port, 1711 destination IP address, destination port, Transaction- 1712 ID, Customer Order Identifier, Provider Order 1713 Identifier} must match an existing order with a state 1714 set to "ServerProcessing". The sequence number carried 1715 in the packet must be larger than the sequence number 1716 maintained by the client. 1717 ACK {Source IP address, source port, destination IP address, 1718 (QUOTATION destination port, Transaction-ID, Customer Order 1719 Transaction) Identifier, Provider Order Identifier, Offered 1720 Connectivity Provisioning Order} must match an order 1721 with a state set to "AcceptSent". The sequence number 1722 carried in the packet must be larger than the sequence 1723 number maintained by the client. 1724 ACK (UPDATE {Source IP address, source port, destination IP address, 1725 Transaction) destination port, Transaction-ID, Customer Order 1726 Identifier, Provider Order Identifier, Updated 1727 Connectivity Provisioning Order} must match an order 1728 with a state set to "AcceptSent". The sequence number 1729 carried in the packet must be larger than the sequence 1730 number maintained by the client. 1731 ACK {Source IP address, source port, destination IP address, 1732 (WITHDRAW destination port, Transaction-ID, Customer Order 1733 Transaction) Identifier, Provider Order Identifier, Empty 1734 Connectivity Provisioning Order} must match an order 1735 with a state set to "Cancelled". The sequence number 1736 carried in the packet must be larger than the sequence 1737 number maintained by the client. 1739 10.2. On the Server Side 1741 Method Validation Checks 1742 ---------- ---------------------------------------------------------- 1743 QUOTATION The source IP address passes existing access filters (if 1744 any). The sequence number carried in the packet must not 1745 be less than the sequence number maintained by the server. 1746 PROCESSING The sequence number carried in the packet must be larger 1747 than the sequence number maintained by the server. 1748 ACCEPT {Source IP address, source port, destination IP address, 1749 destination port, Transaction-ID, Customer Order 1750 Identifier, Provider Order Identifier, Nonce, Offered 1751 Connectivity Provisioning Order} must match an order with 1752 state set to "OfferProposed" or "ProcessngReceived". The 1753 sequence number carried in the packet must be larger than 1754 the sequence number maintained by the server. 1755 DECLINE {Source IP address, source port, destination IP address, 1756 destination port, Transaction-ID, Customer Order 1757 Identifier, Provider Order Identifier, Nonce} must match 1758 an order with state set to "OfferProposed" or 1759 "ProcessngReceived". The sequence number carried in the 1760 packet must be larger than the sequence number maintained 1761 by the server. 1762 UPDATE The source IP address passes existing access filters (if 1763 any) and {Customer Order Identifier, Provider Order 1764 Identifier, Nonce} must match an existing order with state 1765 "Completed". 1766 WITHDRAW The source IP address passes existing access filters (if 1767 any) and {Customer Order Identifier, Provider Order 1768 Identifier, Nonce} must match an existing order with state 1769 "Completed". 1771 11. Theory of Operation 1773 Both CPNP client and server proceeds to message validation checks as 1774 specified in Section 10. 1776 11.1. Client Behavior 1778 11.1.1. Order Negotiation Cycle 1780 To place a provisioning quotation order, the client initiates first a 1781 local quotation order object identified by a unique identifier 1782 assigned by the client. The state of the quotation order is set to 1783 "Created". The client then generates a QUOTATION request which 1784 includes the assigned identifier, possibly an expected response time, 1785 a Transaction-ID and a Requested Connectivity Provisioning Document. 1787 The client may include additional Information Elements such as 1788 Negotiation Options. 1790 The client may be configured to not enforce negotiation checks on 1791 EXPECTED_OFFER_TIME; if so no EXPECTED_RESPONSE_TIME attribute (or 1792 EXPECTED_RESPONSE_TIME set to infinite) should be included in the 1793 quotation order. 1795 Once the request is sent to the server, the state of the request is 1796 set to "PQOSent" and a timer, if a response time is included in the 1797 quotation order, is set to the expiration time as included in the 1798 QUOTATION request. The client also maintains a copy of the extended 1799 transport session details used to generate the QUOTATION request. 1800 The CPNP client must listen on the same port number that it used to 1801 send the QUOTATION request. 1803 If no answer is received from the server before the retransmission 1804 timer expires (i.e., RETRANS_TIMER, Section 8.7), the client proceeds 1805 to retransmission until maximum retry is reached (i.e., 3 times). 1806 The same sequence number is used for retransmitted packets. 1808 If a FAIL message is received, the client may decide to issue another 1809 (corrected) request towards the same server, cancel the local order, 1810 or contact another server. The behavior of the client depends on the 1811 error code returned by the server in the FAIL message. 1813 If a PROCESSING message matching the CPNP transport session is 1814 received, the client updates the CPNP session with the 1815 PROVIDER_AGREEMENT_IDENTIFIER information. If the client does not 1816 accept the expected offer time that may have been indicated in the 1817 PROCESSING message, the client may decide to cancel the quotation 1818 order. If the client accepts the EXPECTED_OFFER_TIME, it changes the 1819 state of the order to "ServerProcessing" and sets a timer to the 1820 value of EXPECTED_OFFER_TIME. If no offer is made before the timer 1821 expires, the client changes the state of the order to "Cancelled". 1823 As a response to a more time request (conveyed in a PROCESSING 1824 message that included a new EXPECTED_OFFER_TIME), the client may 1825 grant this extension by issuing an ACK message or reject the time 1826 extension with a FAIL message having a status code set to "More Time 1827 Rejected". 1829 If an OFFER message matching the extended CPNP session is received, 1830 the client checks if a PROCESSING message having the same 1831 PROVIDER_AGREEMENT_IDENTIFIER has been received from the server. If 1832 a PROCESSING message was already received for the same order but the 1833 PROVIDER_AGREEMENT_IDENTIFIER does not match the identifier included 1834 in the OFFER message, the client ignores silently the message. If a 1835 PROCESSING message having the same PROVIDER_AGREEMENT_IDENTIFIER was 1836 already received and matches the CPNP transaction identifier, the 1837 client changes the state of the order to "OfferReceived" and sets a 1838 timer to the value of VALIDITY_OFFER_TIME indicated in the OFFER 1839 message. 1841 If an offer is received from the server (i.e., as documented in an 1842 OFFER message), the client may accept or reject the offer. The 1843 client accepts the offer by generating an ACCEPT message which 1844 confirms that the client agrees to subscribe to the offer documented 1845 in the OFFER message; the state of the order is passed to 1846 "AcceptSent". The transaction is terminated if an ACK message is 1847 received from the server. If no ACK is received from the server, the 1848 client proceeds with the re-transmission of the ACCEPT message. 1850 The client may also decide to reject the offer by sending a DECLINE 1851 message. The state of the order is set by the client to "Cancelled". 1852 If an offer is not acceptable by the client, the client may decide to 1853 contact a new server or submit another order to the same server. 1854 Guidelines to issue an updated order or terminate the negotiation are 1855 specific to the client. 1857 11.1.2. Order Withdrawal Cycle 1859 A client may withdraw a completed order. This is achieved by issuing 1860 a WITHDRAW message. This message must include Customer Order 1861 Identifier, Provider Identifier and Nonce returned during the order 1862 negotiation cycle specified in Section 11.1.1. 1864 If no ACK is received from the server, the client proceeds with the 1865 re-transmission of the message. 1867 11.1.3. Order Update Cycle 1869 A client may update a completed order. This is achieved by issuing 1870 an UPDATE message. This message must include Customer Order 1871 Identifier, Provider Order Identifier and Nonce returned during the 1872 order negotiation cycle specified in Section 11.1.1. The client must 1873 include in the UPDATE message an updated CPD with the requested 1874 changes. 1876 Subsequent messages exchange is similar to what is documented in 1877 Section 11.1.1. 1879 11.2. Server Behavior 1881 11.2.1. Order Processing 1883 Upon receipt of a QUOTATION message from a client, the server sets a 1884 CPNP session, stores Transaction-ID and generates a Provider Order 1885 Identifier. Once preliminary validation checks are completed ( 1886 Section 10), the server may return a PROCESSING message to notify the 1887 client the quotation order is received and it is under processing; 1888 the server may include an expected offer time to notify the client by 1889 when an offer will be proposed. An order with state 1890 "AwaitingProcessing" is created by the server. The server runs its 1891 decision-making process to decide which offer it can make to honor 1892 the received order. The offer should be made before the expected 1893 offer time expires. 1895 If the server cannot make an offer, it sends backs a FAIL message 1896 with the appropriate error code. 1898 If the server requires more negotiation time, it must send a 1899 PROCESSING message with a new EXPECTED_OFFER_TIME. The client may 1900 grant this extension by issuing an ACK message or reject the time 1901 extension with a FAIL message having a status code set to "More Time 1902 Rejected". If the client doesn't grant more time, the server must 1903 answer before the initial expected offer time; otherwise the client 1904 will ignore the quotation order. 1906 If the server can honor the request or it can make an offer that meet 1907 some of the requirements, it creates an OFFER message. The server 1908 must indicate the Transaction-ID, Customer Order Identifier as 1909 indicated in the QUOTATION message, and the Provider Order Identifier 1910 generated for this order. The server must also include Nonce and the 1911 offered Connectivity Provisioning Document. The server includes an 1912 offer validity time as well. Once sent to the client, the server 1913 changes the state of the order to "OfferSent" and a timer set to the 1914 validity time is initiated. 1916 If the server determines that additional network resources from 1917 another network provider are needed to accommodate a quotation order, 1918 it will create child PQO(s) and will behave as a CPNP client to 1919 negotiate child PQO(s) with possible partnering providers (see 1920 Figure 6). 1922 If no PROCESSING, ACCEPT or DECLINE message is received before the 1923 expiry of the RETRANS_TIMER, the server re-sends the same offer to 1924 the client. This procedure is repeated until maximum retry is 1925 reached. 1927 If an ACCEPT message is received before the offered validity time 1928 expires, the server proceeds with validation checks as specified in 1929 Section 10. The state of the corresponding order is passed to 1930 "AcceptReceived". The server sends back an ACK message to terminate 1931 the order processing cycle. 1933 If a CANCEL/DECLINE message is received, the server proceeds with the 1934 cancellation of the order. The state of the order is then passed to 1935 "Cancelled". 1937 11.2.2. Order Withdrawal 1939 A client may withdraw a completed order by issuing a WITHDRAW 1940 message. Upon receipt of a WITHDRAW message, the server proceeds 1941 with the validation checks, as specified in Section 10. 1943 o If the checks fail, a FAIL message is sent back to the client with 1944 the appropriate error code. 1946 o If the checks succeed, the server clears the clauses of the 1947 Connectivity Provisioning Document, changes the state of the order 1948 to "Cancelled", and sends back an ACK message with an Empty 1949 Connectivity Provisioning Document. 1951 11.2.3. Order Update 1953 A client may update an order by issuing an UPDATE message. Upon 1954 receipt of an UPDATE message, the server proceeds with the validation 1955 checks as specified in Section 10. 1957 o If the checks fail, a FAIL message is sent back to the client with 1958 the appropriate error code. 1959 o Subsequent messages exchange is similar to what is specified in 1960 Section 11.1.1. The server should generate a new Nonce value to 1961 be included in the offer made to the client. 1963 11.3. Sequence Numbers 1965 In each transaction, sequence numbers are used to protect the 1966 transaction against replay attacks. Each communicating partner of 1967 the transaction maintains two sequence numbers, one for incoming 1968 packets and one for outgoing packets. When a partner receives a 1969 message, it will check whether the sequence number in the message is 1970 larger than the incoming sequence number maintained locally. If not, 1971 the messages will be discarded. If the message is proved to be 1972 legal, the value of the incoming sequence number will be replaced by 1973 the value of the sequence number in the message. When a partner 1974 sends out a message, it will insert the value of outgoing sequence 1975 number into the message and increase the outgoing sequence number 1976 maintained locally by 1. 1978 11.4. Message Re-Transmission 1980 If a transaction partner sends out a message and does not receive any 1981 expected reply before the retransmission timer expires (i.e., 1982 RETRANS_TIMER), a transaction partner will try to re-transit the 1983 messages. An exception is the last message (e.g., ACK) sent from the 1984 server in a transaction. After sending this message, the 1985 retransmission timer will be disabled since no additional feedback is 1986 expected. 1988 In addition, if the partner receives a re-sent last incoming packet, 1989 the partner can also send out the answer to the incoming packet with 1990 a limited frequency. If no answer was generated at the moment, the 1991 partner needs to generate a PROCESSING message as the answer. 1993 To benefit message re-transmission, a partner could also store the 1994 last incoming packet and the associated answer. Note that the times 1995 of re-transmission could be decided by the local policy and re- 1996 transmission will not cause any change of sequence numbers. 1998 12. Operational Guidelines 2000 12.1. Logging on the CPNP Server 2002 The CPNP server SHOULD be configurable to log various events and 2003 associated information. Such information includes: 2005 o Client's IP address 2006 o Any event change (e.g., new quotation order, offer sent, order 2007 confirm, order cancellation, order withdraw, etc.) 2008 o Timestamp 2010 12.2. Business Guidelines & Objectives 2012 The CPNP server can operate in the following modes: 2014 1. Fully automated mode: The CPNP server is provisioned with a set 2015 of business guidelines and objectives that will be used as an 2016 input to the decision-making process. The CPNP server will 2017 service received orders that falls into these business 2018 guidelines; otherwise requests will be escalated to an 2019 administrator that will formally validate/invalidate an order 2020 request. The set of policies to be configured to the CPNP server 2021 are specific to each administrative entity managing a CPNP 2022 server. 2024 2. Administrative-based mode: This mode assumes some or all CPNP 2025 server' operations are subject to a formal administrative 2026 validation. CPNP events will trigger appropriate validation 2027 requests that will be forwarded to the contact person(s) or 2028 department which is responsible for validating the orders. 2029 Administrative validation messages are relayed using another 2030 protocol (e.g., SMTP) or a dedicated tool. 2032 Business guidelines are local to each administrative entity. How 2033 validation requests are presented to an administrator are out of 2034 scope of this document; each administrative entity may decide the 2035 appropriate mechanism to enable for that purpose. 2037 13. Security Considerations 2039 Means to defend the server against denial-of-service attacks must be 2040 enabled. For example, access control lists (ACLs) can be enforced on 2041 the client, the server or the network in between, to allow a trusted 2042 client to communicate with a trusted server. 2044 The client and the server should be mutually authenticated. Out of 2045 band mechanisms can be used instead of integrating them into CPNP. 2047 The client must silently discard CPNP responses received from unknown 2048 CPNP servers. The use of a randomly generated Transaction-ID makes 2049 it hard to forge a response from a server with a spoofed IP address 2050 belonging to a legitimate CPNP server. Furthermore, CPNP demands 2051 that messages from the server must include correct identifiers of the 2052 orders. Two order identifiers are used: one generated by the client 2053 and a second one generated by the server. 2055 The Provider must enforce means to protect privacy-related 2056 information included the documents (see Section 8.9) exchanged using 2057 CPNP messages [RFC6462]. In particular, this information must not be 2058 revealed to external parties without the consent of Customers. 2059 Providers should enforce policies to make Customer fingerprinting 2060 difficult to achieve. For more discussion about privacy, refer to 2061 [RFC6462][RFC6973]. 2063 The NONCE and the Transaction ID attributes provide sufficient 2064 randomness and can effectively tolerate attacks raised by off-line 2065 adversaries, who do not have the capability of eavesdropping and 2066 intercepting the packets transported between the client and the 2067 server. Only authorized clients must be able to modify agreed CPNP 2068 orders. The use of a randomly generated NONCE by the server makes it 2069 hard to modify an agreement on behalf of a malicious third-party. 2071 The sequence numbers included in the CPNP messages can be used to 2072 detect replay attacks and antique packets intercepted from on-going 2073 transactions may be re-sent. However, the protocol in its current 2074 version may be vulnerable to replay attacks where the replayed 2075 messages are intercepted from antique transactions. Although the 2076 Transaction ID provided by the client could protect inter-transaction 2077 replay attacks, no protection is provided for the server to deal with 2078 this type of attack. 2080 The protocol does not provide security mechanisms to protect the 2081 confidentiality and integrity of the packets transported between the 2082 client and the server. An underlying security protocol such as 2083 (e.g., DTLS [RFC6347], IPsec) could be used to protect the integrity 2084 and confidentiality for the protocol. In this case, if it is 2085 possible to provide an Automated Key Management (AKM) and associate 2086 each transaction with a different key, inter- transaction replay 2087 attacks can naturally be addressed. If the client and the server use 2088 a single key, an additional mechanism should be provided to protect 2089 inter-transaction replay attacks between them. 2091 The deployment option of a Customer Order Management portal operated 2092 by a trusted third-party (see Section 6) may facilitate the efficient 2093 resolution of the aforementioned security concerns. 2095 14. IANA Considerations 2097 This document does not request any IANA action. 2099 15. Acknowledgements 2101 Thanks to Diego R. Lopez for his comments. 2103 16. References 2105 16.1. Normative References 2107 [RFC1123] Braden, R., Ed., "Requirements for Internet Hosts - 2108 Application and Support", STD 3, RFC 1123, 2109 DOI 10.17487/RFC1123, October 1989, 2110 . 2112 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 2113 Requirement Levels", BCP 14, RFC 2119, 2114 DOI 10.17487/RFC2119, March 1997, 2115 . 2117 [RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker, 2118 "Randomness Requirements for Security", BCP 106, RFC 4086, 2119 DOI 10.17487/RFC4086, June 2005, 2120 . 2122 [RFC5511] Farrel, A., "Routing Backus-Naur Form (RBNF): A Syntax 2123 Used to Form Encoding Rules in Various Routing Protocol 2124 Specifications", RFC 5511, DOI 10.17487/RFC5511, April 2125 2009, . 2127 16.2. Informative References 2129 [ETICS] EU FP7 ETICS Project, "Economics and Technologies of 2130 Inter-Carrier Services", January 2014, . 2134 [I-D.boucadair-lisp-idr-ms-discovery] 2135 Boucadair, M. and C. Jacquenet, "LISP Mapping Service 2136 Discovery at Large", draft-boucadair-lisp-idr-ms- 2137 discovery-01 (work in progress), March 2016. 2139 [I-D.ietf-i2nsf-framework] 2140 Lopez, D., Lopez, E., Dunbar, L., Strassner, J., and R. 2141 Kumar, "Framework for Interface to Network Security 2142 Functions", draft-ietf-i2nsf-framework-04 (work in 2143 progress), October 2016. 2145 [I-D.ietf-l3sm-l3vpn-service-model] 2146 Litkowski, S., Tomotaki, L., and K. Ogaki, "YANG Data 2147 Model for L3VPN service delivery", draft-ietf-l3sm-l3vpn- 2148 service-model-19 (work in progress), November 2016. 2150 [RFC2782] Gulbrandsen, A., Vixie, P., and L. Esibov, "A DNS RR for 2151 specifying the location of services (DNS SRV)", RFC 2782, 2152 DOI 10.17487/RFC2782, February 2000, 2153 . 2155 [RFC4026] Andersson, L. and T. Madsen, "Provider Provisioned Virtual 2156 Private Network (VPN) Terminology", RFC 4026, 2157 DOI 10.17487/RFC4026, March 2005, 2158 . 2160 [RFC4176] El Mghazli, Y., Ed., Nadeau, T., Boucadair, M., Chan, K., 2161 and A. Gonguet, "Framework for Layer 3 Virtual Private 2162 Networks (L3VPN) Operations and Management", RFC 4176, 2163 DOI 10.17487/RFC4176, October 2005, 2164 . 2166 [RFC6347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer 2167 Security Version 1.2", RFC 6347, DOI 10.17487/RFC6347, 2168 January 2012, . 2170 [RFC6462] Cooper, A., "Report from the Internet Privacy Workshop", 2171 RFC 6462, DOI 10.17487/RFC6462, January 2012, 2172 . 2174 [RFC6574] Tschofenig, H. and J. Arkko, "Report from the Smart Object 2175 Workshop", RFC 6574, DOI 10.17487/RFC6574, April 2012, 2176 . 2178 [RFC6770] Bertrand, G., Ed., Stephan, E., Burbridge, T., Eardley, 2179 P., Ma, K., and G. Watson, "Use Cases for Content Delivery 2180 Network Interconnection", RFC 6770, DOI 10.17487/RFC6770, 2181 November 2012, . 2183 [RFC6793] Vohra, Q. and E. Chen, "BGP Support for Four-Octet 2184 Autonomous System (AS) Number Space", RFC 6793, 2185 DOI 10.17487/RFC6793, December 2012, 2186 . 2188 [RFC6830] Farinacci, D., Fuller, V., Meyer, D., and D. Lewis, "The 2189 Locator/ID Separation Protocol (LISP)", RFC 6830, 2190 DOI 10.17487/RFC6830, January 2013, 2191 . 2193 [RFC6973] Cooper, A., Tschofenig, H., Aboba, B., Peterson, J., 2194 Morris, J., Hansen, M., and R. Smith, "Privacy 2195 Considerations for Internet Protocols", RFC 6973, 2196 DOI 10.17487/RFC6973, July 2013, 2197 . 2199 [RFC7149] Boucadair, M. and C. Jacquenet, "Software-Defined 2200 Networking: A Perspective from within a Service Provider 2201 Environment", RFC 7149, DOI 10.17487/RFC7149, March 2014, 2202 . 2204 [RFC7215] Jakab, L., Cabellos-Aparicio, A., Coras, F., Domingo- 2205 Pascual, J., and D. Lewis, "Locator/Identifier Separation 2206 Protocol (LISP) Network Element Deployment 2207 Considerations", RFC 7215, DOI 10.17487/RFC7215, April 2208 2014, . 2210 [RFC7297] Boucadair, M., Jacquenet, C., and N. Wang, "IP 2211 Connectivity Provisioning Profile (CPP)", RFC 7297, 2212 DOI 10.17487/RFC7297, July 2014, 2213 . 2215 Authors' Addresses 2217 Mohamed Boucadair 2218 Orange 2219 Rennes 35000 2220 France 2222 Email: mohamed.boucadair@orange.com 2224 Christian Jacquenet 2225 Orange 2226 Rennes 35000 2227 France 2229 Email: christian.jacquenet@orange.com 2231 Dacheng Zhang 2232 Huawei Technologies 2234 Email: zhangdacheng@huawei.com 2236 Panos Georgatsos 2237 Centre for Research and Innovation Hellas 2238 78, Filikis Etairias str. 2239 Volos, Hellas 38334 2240 Greece 2242 Phone: +302421306070 2243 Email: pgeorgat@iti.gr