idnits 2.17.1 draft-boucadair-connectivity-provisioning-protocol-11.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 (March 14, 2016) is 2936 days in the past. Is this intentional? Checking references for intended status: Experimental ---------------------------------------------------------------------------- -- 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: Experimental Orange 5 Expires: September 15, 2016 D. Zhang 6 Huawei Technologies 7 P. Georgatsos 8 CERTH 9 March 14, 2016 11 Connectivity Provisioning Negotiation Protocol (CPNP) 12 draft-boucadair-connectivity-provisioning-protocol-11 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 September 15, 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 . . . . . . . . . . . . . . . . . . . . 20 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. ACK . . . . . . . . . . . . . . . . . . . . . . . . . 31 106 9.2.6. DECLINE . . . . . . . . . . . . . . . . . . . . . . . 32 107 9.2.7. CANCEL . . . . . . . . . . . . . . . . . . . . . . . 33 108 9.2.8. WITHDRAW . . . . . . . . . . . . . . . . . . . . . . 33 109 9.2.9. UPDATE . . . . . . . . . . . . . . . . . . . . . . . 34 110 9.2.10. FAIL . . . . . . . . . . . . . . . . . . . . . . . . 35 111 10. Message Validation . . . . . . . . . . . . . . . . . . . . . 36 112 10.1. On the Client Side . . . . . . . . . . . . . . . . . . . 36 113 10.2. On the Server Side . . . . . . . . . . . . . . . . . . . 37 114 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 . . . . . . . . . . . . . . . . . . . . 40 120 11.2.1. Order Processing . . . . . . . . . . . . . . . . . . 40 121 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 . . . . . . . . . . . . . . . . . . . . . . 46 131 16. References . . . . . . . . . . . . . . . . . . . . . . . . . 46 132 16.1. Normative References . . . . . . . . . . . . . . . . . . 46 133 16.2. Informative References . . . . . . . . . . . . . . . . . 46 134 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 48 136 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 o 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 o 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 o 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 o 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 o Agreement: Refers to an order placed by the Customer and accepted 244 by 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 o 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 o 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 1. Frozen model: The Customer cannot actually negotiate the 294 parameters of the service(s) offered by a Provider. After 295 consulting the Provider's service portfolio, the Customer selects 296 the service offer he/she wants to subscribe and places an order 297 to the Provider. Order handling is quite simple on the Provider 298 side 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 301 share the same Customer Provisioning Profile). 303 2. Negotiation-based model: Unlike the frozen model, the Customer 304 documents his/her requirements in a request for a quotation, 305 which is then sent to one or several Providers. Solicited 306 Providers check whether they can address these requirements or 307 not, and get back to the Customer accordingly, possibly with an 308 offer that may not exactly match customer's requirements (e.g., a 309 100 Mbps connection cannot be provisioned given the amount of 310 available resources, but an 80 Mbps connection can be provided). 311 A negotiation between the Customer and the Provider(s) then 312 follows 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. LISP ([RFC6830]) Mapping Service Providers can use CPNP to enrich 424 their mapping database by interconnecting their mapping system 425 (see Figure 2). This interconnection allows to relax the 426 constraints on PxTR in favour of native LISP forwarding. Also, 427 it allows to prevent fragmented LISP mapping database. A 428 framework is described in [I-D.boucadair-lisp-idr-ms-discovery]. 430 ,--,--,--. ,--,--,--. 431 ,-' `-. ,-' `-. 432 (Mapping System 'A')===(Mapping System 'B') 433 `-. ,-' `-. ,-' 434 `--'--'--' `--'--'--' 436 Figure 2: LISP Mapping System Interconnect 438 6. CPNP Deployment Models 440 Several CPNP deployment models can be envisaged. Two examples are 441 listed below: 443 o The Customer deploys a CPNP client while one or several CPNP 444 servers are deployed by the Provider. 445 o The Customer does not enable any CPNP client. The Provider 446 maintains a Customer Order Management portal. The Customer can 447 initiate connectivity provisioning quotation orders via the 448 portal; appropriate CPNP messages are then generated and sent to 449 the relevant CPNP server. In this model, both the CPNP client and 450 CPNP server are under the responsibility of the same 451 administrative entity (i.e., Network Provider). 453 Once the negotiation of connectivity provisioning parameters is 454 successfully concluded that is, an order has been placed by the 455 Customer, the actual network provisioning operations are initiated. 456 The specification of related dynamic resource allocation and policy 457 enforcement schemes, as well as how CPNP servers interact with the 458 network provisioning functional blocks at Provider sides are out of 459 the scope of this document. 461 This document does not make any assumption about the CPNP deployment 462 model either. 464 7. CPNP Negotiation Model 466 CPNP runs between a Customer and a Provider carrying service orders 467 from the Customer and respective responses from the Provider to the 468 end of reaching a connectivity service provisioning agreement. As 469 the services offered by the Provider are well-described, by means of 470 the CPP template, the negotiation process is essentially a value- 471 settlement process, where an agreement is pursued on the values of 472 the commonly understood information items (service parameters) 473 included in the service description template. 475 The protocol is transparent to the content that it carries and to the 476 negotiation logic, at Customer and Provider sides, that manipulates 477 the content. 479 The protocol aims at facilitating the execution of the negotiation 480 logic by providing the required generic communication primitives. 482 Since negotiations are initiated and primarily driven by the 483 Customer's negotiation logic, it is reasonable to assume that the 484 Customer can only call for an agreement. An implicit approach is 485 adopted for not overloading the protocol with additional messages. 486 In particular, the acceptance of an offer made by the Provider 487 signals a call for agreement from the Customer. Note that it is 488 almost certain the Provider to accept this call since it refers to an 489 offer that itself made. Of course, at any point the Provider or the 490 Customer may quit the negotiations, each on its own grounds. 492 Based on the above, CPNP adopts a Quotation Order/Offer/Answer model, 493 which proceeds through the following basic steps: 495 1. The client specifies its service requirements via a Provision 496 Quotation Order (PQO). The order may include fixed or loosely 497 defined values in the clauses describing service provisioning 498 characteristics. 500 2. The server declines the PQO, or makes an offer to address the 501 requirements of the PQO, or which may suggests a counter- 502 proposals that partially addresses the requirements of the PQO 503 for specific requirements that cannot be accommodated. 505 3. The client either accepts or declines the offer. Accepting the 506 offer implies a call for agreement. 508 Multiple instances of CPNP may run at Customer or Provider domains. 509 A CPNP client may be engaged simultaneously in multiple negotiations 510 with the same or different CPNP servers (parallel negotiations, see 511 Section 8.11) and a CPNP server may need to negotiate with other 512 Provider(s) as part of negotiations with a CPNP client (cascaded 513 negotiations, see Section 8.10). 515 CPNP relies on various timers to achieve its operations. These 516 timers are used to guide the negotiation logic at both CPNP client 517 and CPNP server sides, particularly in cases where the CPNP client is 518 involved in parallel negotiations with several CPNP servers or in 519 cases where the CPNP server is, in its turn, involved in negotiations 520 with other Providers for processing a given quotation order. Related 521 to the above, CPNP allows the CPNP server to request for more time. 522 This request may be accepted or rejected by the CPNP client. 524 Providers may need to publish available services to the Customers 525 (see Section 4). CPNP may optionally support this functionality. 526 Dedicated templates can be defined for the purpose of service 527 announcements, which will be used by the CPNP clients to initiate 528 their CPNP negotiation cycles. 530 For simplicity, a single Offer/Answer stage is assumed within one a 531 CPNP negotiation cycle. Nevertheless, as stated before, multiple 532 CPNP negotiation cycles can be undertaken by a CPNP client (see 533 Figure 3). 535 The model is flexible as it can accommodate changing conditions over 536 time (e.g., introduction of an additional VPN site). 538 +------+ +------+ +------+ +------+ 539 |Client| |Server| |Client| |Server| 540 +------+ +------+ +------+ +------+ 541 |=====Quotation Order=====>| |=====Quotation Order=====>| 542 |<==========Offer==========| |<==========Offer==========| 543 |===========Accept========>| |==========Decline========>| 545 1-Step Successful Negotiation 1-Step Failed Negotiation 546 Cycle Cycle 548 +------+ +------+ +------+ +------+ 549 |Client| |Server| |Client| |Server| 550 +------+ +------+ +------+ +------+ 551 |===Quotation Order(a)====>| |===Quotation Order(i)====>| 552 |<==========Offer==========| |<==========Offer==========| 553 |==========Decline========>| |==========Decline========>| 554 |===Quotation Order(b)====>| |===Quotation Order(j)====>| 555 |<==========Offer==========| |<==========Offer==========| 556 |===========Accept========>| |==========Decline========>| 557 |===Quotation Order(k)====>| 558 |<==========Offer==========| 559 |==========Decline========>| 560 |===Quotation Order(l)====>| 561 |<==Fail to make an offer==| 563 N-Step Negotiation Cycle: N-Step Negotiation Cycle: 564 Successful Negotiation Failed Negotiation 566 Figure 3: Overall Negotiation Process 568 8. Protocol Overview 570 8.1. Client/Server Communication 572 CPNP is a client/server protocol which is designed to run over any 573 transport protocol with UDP being the default transport mode. No 574 permanent CPNP session needs to be maintained between the client and 575 the server. There is no need to run CPNP over a reliable transport 576 mode because CPNP messages are acknowledged. 578 The server uses CPNP_PORT (see Section 14) to bind the CPNP service. 579 The client sends CPNP messages to CPNP_PORT. The same port used as 580 the source port of the request sent to the server must be used by the 581 server to reply to that request. 583 CPNP is independent of the IP address family. 585 CPNP retransmission is discussed in Section 11.4. 587 8.2. Server Discovery 589 The CPNP client can be configured with the CPNP server(s) using 590 manual or dynamic configuration means. For example, Providers may 591 configure dedicated SRV records ([RFC2782]) or may use a well-known 592 name/address. 594 Discussions about how the client can discovers its the server(s) of 595 its interest are out of the scope of this document. The document 596 assumes that a the required CPNP server can be reached by the CPNP 597 client, thanks to some configuration means. 599 8.3. Policy Configuration on the CPNP Server 601 As an input to its decision-making process, the CPNP server may be 602 connected to various external modules such as: Customer Profiles, 603 Network Topology, Network Resource Management, Orders Repository, AAA 604 and Network Provisioning Manager (an example is shown in Figure 4). 606 These external modules provide inputs to the CPNP server, so that it 607 can: 609 o Check whether a customer is entitled to initiate a provisioning 610 quotation request. 612 o Check whether a customer is entitled to cancel an on-going order. 614 o Check whether administrative data (e.g., billing-related 615 information) have been verified before starting handling the 616 request. 618 o Check whether network capacity is available or additional capacity 619 is required. 621 o Receive guidelines from network design and sales blocks (e.g., 622 pricing, network usage levels, threshold on number of CPP 623 templates that can be processed over a given period of time as a 624 function of the nature of the service to be delivered, etc.). 626 o Transfer completed orders to network provisioning blocks. 628 The above list of CPNP server operations is not exhaustive. 630 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 631 .Business & Administrative Management . 632 .+------------------------++---------------------------+. 633 .| Business Guidelines || Billing & Charging |. 634 .+-----------+------------++-----------+---------------+. 635 . | | . 636 . +-------------------+ | . 637 . . . . . . . . . . . . . . . . .|. . .|. . . . . . . . . 638 . . . . . . . . . . . . . . . . .|. . .|. . . . . . . . . 639 .Order Handling Management | | . 640 . +-------------------+ +-------+-----+--------------+ . 641 . |Network Topology DB+--+ CPNP Server | . 642 . +-------------------+ +-+---+---+---+---+-----+----+ . 643 . | | | | | | . 644 . +------------------------+-+ | | | | | . 645 . | Network Dimensioning | | | | | | . 646 . | & Planning | | | | | | . 647 . +--------------------------+ | | | | | . 648 . +----------------------------+-+ | | | +---+----+ . 649 . | | | | | | AAA | . 650 . | Network +------------+ | | | +--------+ . 651 . | Resource | +------------+-+ | +-+----------+ . 652 . | Management | | Customer | | | Orders | . 653 . | | | Profiles | | | Repository | . 654 . +-----------------+ +--------------+ | +------------+ . 655 . . . . . . . . . . . . . . . . . . . .|. . . . . . . . . 656 +--------------------------------------+----------------+ 657 | Network Provisioning Manager | 658 +-------------------------------------------------------+ 660 Figure 4: Order Handling Management Functional Block 662 The following order handling modes can be also configured on the 663 server: 665 1. Fully automated mode: This mode does not require any action from 666 the administrator when receiving a request for a service. The 667 server can execute its decision-making process related to the 668 orders received and generate corresponding offers. 669 2. Administrative validation checking: Some or all of the server's 670 operations are subject to administrative validation procedures. 671 This mode requires an action from the administrator for every 672 request received. The CPNP methods which can be automatically 673 handled by the server or they are subject to one or several 674 validation administrative checks can be configured on the server. 676 8.4. CPNP Session 678 Both the client and server maintain the following CPNP transport 679 session information: 681 A CPNP session is identified by the following items: 683 o IP address of the client 684 o Client's port number 685 o IP address of the server 686 o Server's port number 688 8.5. Extended CPNP Session 690 An extended PQO session is denoted by a 5-uplet defined as follows: 692 o CPNP session (Section 8.4) 694 o Incremented Sequence Number (Section 11.3) 696 o Customer Agreement Identifier: This is a unique identifier 697 assigned to the order under negotiation by the client 698 (Section 9.1.1). This identifier is also used to identify the 699 agreement that will result from a successful negotiation. 701 o Provider Agreement Identifier: This is a unique identifier 702 assigned to the order under negotiation by the server 703 (Section 9.1.2). This identifier is also used to identify the 704 agreement that will result from a successful negotiation. 706 o Transaction-ID (Section 9.1.3) 708 8.6. CPNP Transaction 710 A CPNP transaction occurs between a client and a server for pursuing, 711 modifying, withdrawing a service agreement and comprises all CPNP 712 messages exchanged between the client and the server, from the first 713 request sent by the client to the final response sent by the server. 714 A CPNP transaction is bound to a CPNP session. 716 Because multiple CPNP transactions can be maintained by the CPNP 717 client, the client must assign an identifier to uniquely identify a 718 given transaction. This identifier is denoted as Transaction-ID. 720 The Transaction-ID must be randomly assigned by the CPNP client, 721 according to the best current practice for generating random numbers 722 [RFC4086] that cannot be guessed easily. Transaction-ID is used for 723 validating CPNP responses received by the client. 725 In the context of a transaction, the client needs to randomly select 726 a sequence number and assign it in the first CPNP message to send. 727 This number is then incremented for each request message is 728 subsequently sent within the on-going CPNP transaction (see 729 Section 11.3). 731 8.7. CPNP Timers 733 CPNP adopts a simple retransmission procedure which relies on a 734 retransmission timer denoted as RETRANS_TIMER and maximum retry 735 threshold. The use of RETRANS_TIMER and a maximum retry threshold 736 are described in Section 11. 738 The response timer (RESPONSE_TIMER) is set by the client to denote 739 the time, in seconds, the client will wait for receiving a response 740 from the server to a provisioning quotation order request (see 741 Section 9.1.6). If the timer expires, the respective quotation order 742 is cancelled by the client and a CANCEL message is generated 743 accordingly. 745 An offer expiration timer (EXPIRE_TIMER) is set by the server to 746 represent the time, in minutes, after which an offer made by the 747 server will be invalid (see Section 9.1.8). 749 8.8. CPNP Operations 751 The current CPNP operations are listed below. They may be augmented, 752 depending on the nature of some transactions or because of security 753 considerations that may necessitate a distinct CPNP client/server 754 authentication phase before negotiation begins. 756 o QUOTATION: 758 This operation is used by the client to initiate a provisioning 759 quotation order. Upon receipt of a QUOTATION request, the server 760 may respond with a PROCESSING, OFFER or a FAIL message. A 761 QUOTATION-initiated transaction can be terminated by a FAIL 762 message. 764 o PROCESSING: 766 This operation is used to inform the remote party that the message 767 (the order quotation or the offer) sent was received and it is 768 processed. This message can also be issued by the server to 769 request more time, in which case the client may reply with an ACK 770 or FAIL message depending on whether more time can or cannot be 771 granted. 773 o OFFER: 775 This operation is used by the server to inform the client about an 776 offer that can best accommodate the requirements indicated in the 777 previously received QUOTATION message. 779 o ACCEPT: 781 This operation is used by the client to confirm the acceptance of 782 an offer made by the server. This message implies a call for 783 agreement. An agreement is reached when an ACK is subsequently 784 received from the server, which is likely to happen; it is rather 785 unlikely the server to reject an offer that it has already made. 787 o ACK: 789 This operation is used by the server to acknowledge the receipt of 790 an ACCEPT or WITHDRAW message, or by the client to confirm the 791 time extension requested by the server for processing the last 792 received quotation order. 794 o DECLINE: 796 This operation is used by the client to reject an offer made by 797 the server. The on-going transaction may not be terminated 798 immediately, e.g., the server/client may issue another offer/ 799 order. 801 o CANCEL: 803 This operation is used by the client to cancel (quit) the on-going 804 transaction. 806 o WITHDRAW: 808 This operation is used by the client to withdraw an agreement. 810 o UPDATE: 812 This operation is used by the client to update an existing 813 agreement. For example, this method can be invoked to add a new 814 site. This method will trigger a new negotiation cycle. 816 o FAIL: 818 This operation is used by the server to indicate that it cannot 819 accommodate the requirements documented in the PQO conveyed in the 820 QUOTATION message or to inform the client about an error 821 encountered when processing the received message. In either case, 822 the message implies that the server is unable to make offers and 823 as such it terminates the on-going transaction. 825 This message is also used by the client to reject a time extension 826 request received from the server (in a PROCESSING message). The 827 message includes a status code for providing explanatory 828 information. 830 Evidently, the above CPNP primitives are service-independent. CPNP 831 messages may transparently carry service-specific objects which are 832 handled by the negotiation logic at either side. The document 833 specifies the service objects that are required for connectivity 834 provisioning negotiation (see Section 8.9). Additional service- 835 specific objects to be carried in the CPNP messages can be defined in 836 the future for accommodating alternative deployment or other service 837 provisioning needs. 839 8.9. Connectivity Provisioning Documents 841 CPNP makes use of several flavors of Connectivity Provisioning 842 Documents (CPD). These documents follow the CPP template described 843 in [RFC7297]. 845 o Requested Connectivity Provisioning Document (Requested CPD): 847 refers to the CPD included by a CPNP client in a QUOTATION 848 request. 850 o Offered Connectivity Provisioning Document (Offered CPD): 852 This document is included by a CPNP server in an OFFER message. 853 Its information reflects the proposal of the server to accommodate 854 all or a subset of the clauses depicted in a Requested CPD. A 855 validity time is associated with the offer made. 857 o Agreed Connectivity Provisioning Document (Agreed CPD): 859 If the client accepts an offer made by the server, the Offered CPD 860 is included in an ACCEPT message. This CPD is also included in an 861 ACK message. Thus, a 3-way hand-shaking procedure is followed for 862 successfully concluding the negotiation. 864 Figure 5 shows a typical CPNP negotiation cycle and the use of the 865 different types of Connectivity Provisioning Documents. 867 +------+ +------+ 868 |Client| |Server| 869 +------+ +------+ 870 |======QUOTATION (Requested CPD)=====>| 871 |<============PROCESSING==============| 872 |<========OFFER (Offered CPD)=========| 873 |=============PROCESSING=============>| 874 |=========ACCEPT (Agreed CPD)========>| 875 |<=========ACK (Agreed CPD)===========| 877 Figure 5: Connectivity Provisioning Documents 879 A provisioning document can include parameters with fixed values, 880 loosely defined values, or a combination thereof. A provisioning 881 document is said to be concrete if all clauses have fixed values. 883 A typical evolution of a negotiation cycle would start with a 884 quotation order with loosely defined parameters, and then, as offers 885 are made, it would conclude with concrete provisioning document for 886 calling for the agreement. 888 8.10. Child Provisioning Quotation Orders 890 If the server detects that network resources from another Network 891 Provider need to be allocated in order to accommodate the 892 requirements described in a PQO (e.g., in the context of an inter- 893 domain VPN service, additional PE router resources need to be 894 allocated), the server may generate child PQOs to request the 895 appropriate network provisioning operations (see Figure 6). In such 896 situation, the server behaves also as a CPNP client. The server 897 associates the parent order with its child PQOs. This is typically 898 achieved by locally adding the reference of the child PQO to the 899 parent order. 901 +------+ +--------+ +--------+ 902 |Client| |Server A| |Server B| 903 +------+ +--------+ +--------+ 904 | | | 905 |=====QUOTATION=====>| | 906 |<====PROCESSING=====| | 907 | |=====QUOTATION=====>| 908 | |<====PROCESSING=====| 909 | |<=======OFFER=======| 910 | |=====PROCESSING====>| 911 | |=======ACCEPT======>| 912 | |<=======ACK=========| 913 |<=======OFFER=======| | 914 |=====PROCESSING====>| | 915 |=======ACCEPT======>| | 916 |<=======ACK=========| | 918 Figure 6: Example of Child Orders 920 8.11. Negotiations with Multiple CPNP Servers 922 A CPNP client may undertake multiple negotiations in parallel with 923 several servers for practical reasons such as cost optimization and 924 fail-safety. The multiple negotiations may lead to one or many 925 agreements. Multiple negotiations with the same Provider are not 926 precluded. 928 The salient point underlining the parallel negotiations scenario is 929 that although the negotiation protocol is strictly between two 930 parties, the negotiation logic may not necessarily be. The CPNP 931 client negotiation logic may need to collectively drive parallel 932 negotiations, as the negotiation with one server may affect the 933 negotiation with other servers; e.g., it may need to use the 934 responses from all servers as input for determining the messages (and 935 their content) to subsequently send in each individual negotiation. 936 Timing is therefore an important aspect at the client's. The CPNP 937 client needs to have the ability to synchronize the receipt of the 938 responses from the servers. CPNP takes into account this requirement 939 by allowing clients to specify in the QUOTATION message the time by 940 which the server needs to respond (see Section 9.1.6). 942 8.12. State Management 944 Both the client and the server maintain repositories to store on- 945 going orders. How these repositories are maintained is deployment- 946 specific. It is out of scope of this document to elaborate on such 947 considerations. Timestamps are also logged to track state change. 948 Tracking may be needed for various reasons,including regulatory ones. 950 8.12.1. On the Client Side 952 The following lists the states which can be associated with a given 953 order on the client's side: 955 o Created: when the order has been created. It is not handled by 956 the client until the administrator allows to process it. 958 o AwaitingProcessing: when the administrator approved of processing 959 a created order and the order has not been handled yet. 961 o PQOSent: when the order has been sent to the server. 963 o ServerProcessing: when the server has confirmed the receipt of the 964 order. 966 o OfferReceived: when an offer has been received from the server. 968 o OfferProcessing: when a received offer is currently processed by 969 the client. 971 o AcceptSent: when the client confirmed the offer to the server. 973 o AcceptAck: when the offer is acknowledged by the server. 975 o Cancelled: when the order has failed or cancelled. 977 +------------------+ 978 | Created |-----------------+ 979 +------------------+ | 980 | | 981 v | 982 +------------------+ | 983 |AwaitingProcessing|----------------+| 984 +------------------+ || 985 | || 986 QUOTATION || 987 v || 988 +------------------+ || 989 | PQOSent |---CANCEL------+|| 990 +------------------+ vvv 991 | +-----+ 992 PROCESSING | | 993 v | | 994 +------------------+ CANCEL | C | 995 | ServerProcessing |------------>| A | 996 +------------------+ FAIL | N | 997 | | C | 998 | | E | 999 OFFER | L | 1000 | | L | 1001 v | E | 1002 +------------------+ | D | 1003 | OfferReceived |---CANCEL--->| | 1004 +------------------+ | | 1005 | PROCESSING +-----+ 1006 v ^^^ 1007 +------------------+ ||| 1008 | OfferProcessing |---DECLINE-----+|| 1009 +------------------+ || 1010 | ACCEPT || 1011 v || 1012 +------------------+ || 1013 | AcceptSent |---CANCEL-------+| 1014 +------------------+ | 1015 | ACK | 1016 v | 1017 +------------------+ | 1018 | AcceptAck |---WITHDRAW------+ 1019 +------------------+ 1021 Figure 7: CPNP Finite State Machine (Client Side) 1023 8.12.2. On the Server Side 1025 The following lists the states which can be associated with a given 1026 order and a corresponding offer on the server's side: 1028 o PQOReceived: when the order has been received from the client. 1030 o AwaitingProcessing: when the order is being processed by the 1031 server. An action from the server administrator may be needed. 1033 o OfferProposed: when the request has been successfully handled and 1034 an offer has been sent to the client. 1036 o ProcessingReceived: when the server received a PROCESSING for an 1037 offer sent to the client. 1039 o AcceptReceived: when the server received a confirmation for the 1040 offer from the client. 1042 o AcceptAck: when the server acknowledged the offer (accepted by 1043 client) to the client. 1045 o Cancelled: when the order has failed to be met or it has been 1046 cancelled by the client. Associate resources must be released in 1047 the latter case, if prior reserved. 1049 o ChildCreated: when a child order has been created in cases where 1050 resources from another Network Provider are needed. 1052 o ChildPQOSent: when a child order has been sent to the remote 1053 server. 1055 o ChildServerProcessing: when a child order is currently processed 1056 by the remote server. 1058 o ChildOfferReceived: when an offer has been received to a child 1059 order from the remote server. 1061 o ChildOfferProcessing: when a received offer to a child order is 1062 currently processed. 1064 o ChildAcceptSent: when the child offer (offer received from the 1065 remote server in response to a child order) is confirmed to the 1066 remote server. 1068 o ChildAcceptAck: when an accepted child offer is acknowledged by 1069 the remote server. 1071 +------------------+ 1072 +---------------------| ChildCreated | 1073 | +------------------+ 1074 v | ^ 1075 +------------------+ | | 1076 | ChildPQOSent |----------------+| Q 1077 +------------------+ || U 1078 | || O 1079 QUOTATION || T 1080 v || A +--------------------+ 1081 +---------------------+ CANCEL || T | PQOReceived | 1082 |ChildServerProcessing|------------+|| I +--------------------+ 1083 +---------------------+ FAIL vvv O | | 1084 | +-----+ N CANCEL | 1085 PROCESSING | |<---|-------+ PROCESSING 1086 v | | | v 1087 +------------------+ | | +------------------------+ 1088 |ChildOfferReceived|----CANCEL---| C |<--| AwaitingProcessing | 1089 +------------------+ | A | +------------------------+ 1090 | | N | ^ | OFFER 1091 OFFER | C | | +------------------+ 1092 | | 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. 1312 9.2.1. QUOTATION 1314 The format of the QUOTATION message is shown below: 1316 ::= 1317 1318 1319 1320 1321 [] 1322 1323 [...] 1325 A QUOTATION message must include an order identifier which is 1326 generated by the client. Because several orders can be issued to 1327 several servers, the QUOTATION message must also include a 1328 Transaction-ID. 1330 The message may include an EXPECTED_RESPONSE_TIME which indicates by 1331 when the client is expecting to receive an offer from the server. 1332 QUOTATION message must also include a requested connectivity 1333 provisioning document. 1335 When the client sends the QUOTATION message to the server, the state 1336 of the order changes to "PQOSent". 1338 9.2.2. PROCESSING 1340 The format of the PROCESSING message is shown below: 1342 ::= 1343 1344 1345 1346 1347 1348 [] 1350 Upon receipt of a QUOTATION message, the server proceeds with parsing 1351 rules (see Section 10). If no error is encountered, the server 1352 generates a PROCESSING response to the client to indicate the PQO has 1353 been received and it is being processed. The server must generate an 1354 order identifier which identifies the order in its local order 1355 repository. The server MUST copy the content of 1356 CUSTOMER_AGREEMENT_IDENTIFIER and TRANSACTION_ID fields as conveyed 1357 in the QUOTATION message. The server may include an 1358 EXPECTED_OFFER_TIME by when it expects to make an offer to the 1359 client. 1361 Upon receipt of a PROCESSING message, the client verifies whether it 1362 has issued a PQO to that server and which contains the 1363 CUSTOMER_AGREEMENT_IDENTIFIER and TRANSACTION_ID. If no such PQO is 1364 found, the PROCESSING message is silently ignored. If a PQO is 1365 found, the client may check if it accepts the EXPECTED_OFFER_TIME and 1366 then, it changes to state of the order to "ServerProcessing". 1368 If more time is required by the server to process the quotation 1369 order, it may send a PROCESSING message that includes a new 1370 EXPECTED_OFFER_TIME. The client can answer with an ACK message if 1371 more time is granted (Figure 10) or with a FAIL message if the time 1372 extension is rejected (Figure 11). 1374 +------+ +------+ 1375 |Client| |Server| 1376 +------+ +------+ 1377 |=======QUOTATION(Requested CPD)=====>| 1378 |<========PROCESSING(time1)===========| 1379 ... 1380 |<========PROCESSING(MoreTime)========| 1381 |============ACK(TimeGranted)========>| 1382 ... 1383 |<=========OFFER(Offered CPD)=========| 1384 |=============PROCESSING=============>| 1385 |==========ACCEPT(Agreed CPD)========>| 1386 |<==========ACK(Agreed CPD)===========| 1388 Figure 10: Request more negotiation time: Granted 1390 +------+ +------+ 1391 |Client| |Server| 1392 +------+ +------+ 1393 |=======QUOTATION(Requested CPD)=====>| 1394 |<========PROCESSING(time1)===========| 1395 ... 1396 |<========PROCESSING(MoreTime)========| 1397 |===========FAIL(TimeRejected)=======>| 1399 Figure 11: Request more negotiation time: Rejected 1401 9.2.3. OFFER 1403 The format of the OFFER message is shown below: 1405 ::= 1406 1407 1408 1409 1410 1411 1412 1413 1414 [...] 1416 The server answers with an OFFER message to a QUOTATION request 1417 received from the client. The offer will be considered as rejected 1418 by the client if no confirmation (ACCEPT message sent by the client) 1419 is received by the server before the expiration of the validity time. 1421 9.2.4. ACCEPT 1423 The format of the ACCEPT message is shown below: 1425 ::= 1426 1427 1428 1429 1430 1431 1432 1433 [...] 1435 This message is used by a client to confirm the acceptance of an 1436 offer received from a server. The fields of this message are copied 1437 from the received OFFER message. 1439 9.2.5. ACK 1441 The format of the ACK message is shown below: 1443 ::= 1444 1445 1446 1447 1448 1450 [] 1451 [] 1452 [...] 1454 This message is issued by the server to close a CPNP transaction or 1455 by a client to grant more negotiation time to the server. 1457 This message is sent by the server as a response to an ACCEPT, 1458 WITHDRAW, DECLINE, or CANCEL message. In such case, the ACK message 1459 must include the copy of the Connectivity Provisioning Document as 1460 stored by the server, in particular: 1462 o A copy of the requested/offered CPD is included by the server if 1463 it successfully handled a CANCEL message. 1464 o A copy of the updated CPD is included by the server if it 1465 successfully handled an UPDATE message. 1466 o A copy of the offered CPD is included by the server if it 1467 successfully handled an ACCEPT message in the context of a 1468 QUOTATION transaction. 1469 o An empty CPD is included by the server if it successfully handled 1470 a DECLINE message. 1472 A client may issue an ACK message as a response to a more time 1473 request (conveyed in PROCESSING) received from the server. In such 1474 case, the ACK message must include an EXPECTED_RESPONSE_TIME that is 1475 likely to be set to the time extension requested by the server. 1477 9.2.6. DECLINE 1479 The format of the DECLINE message is shown below: 1481 ::= 1482 1483 1484 1485 1486 1487 1489 The client can issue a DECLINE message to reject an offer. 1490 CUSTOMER_AGREEMENT_IDENTIFIER, PROVIDER_AGREEMENT_IDENTIFIER, 1491 TRANSACTION_ID, and NONCE are used by the server as keys to find the 1492 corresponding order. If an order matches, the server changes the 1493 state of this order to "Cancelled" and then returns an ACK with a 1494 copy of the requested CPD to the requesting client. 1496 If no order is found, the server returns a FAIL message to the 1497 requesting client. 1499 A flow example is shown in Figure 12. 1501 +------+ +------+ 1502 |Client| |Server| 1503 +------+ +------+ 1504 |=======QUOTATION(Requested CPD)=====>| 1505 |<============PROCESSING==============| 1506 |<=========OFFER(Offered CPD)=========| 1507 |=============PROCESSING=============>| 1508 |===============DECLINE==============>| 1509 |<================ACK=================| 1511 Figure 12: DECLINE Flow Example 1513 9.2.7. CANCEL 1515 The format of the CANCEL message is shown below: 1517 ::= 1518 1519 1520 1521 1522 [] 1524 The client can issue a CANCEL message at any stage during the CPNP 1525 negotiation process before an agreement is reached. 1526 CUSTOMER_AGREEMENT_IDENTIFIER and TRANSACTION_ID are used by the 1527 server as keys to find the corresponding order. If a quotation order 1528 matches, the server changes the state of this quotation order to 1529 "Cancelled" and then returns an ACK with a copy of the requested CPD 1530 to the requesting client. 1532 If no quotation order is found, the server returns a FAIL message to 1533 the requesting client. 1535 9.2.8. WITHDRAW 1537 The format of the WITHDRAW message is shown below: 1539 ::= 1540 1541 1542 1543 1544 1545 1546 [] 1548 [...] 1550 This message is used to withdraw an offer already subscribed by the 1551 Customer. Figure 13 shows a typical usage of this message. 1553 +------+ +------+ 1554 |Client| |Server| 1555 +------+ +------+ 1556 |============WITHDRAW(CPD)===========>| 1557 |<============PROCESSING==============| 1558 |<===========ACK(Empty CPD)===========| 1560 Figure 13: WITHDRAW Flow Example 1562 The CPNP must include the same CUSTOMER_AGREEMENT_IDENTIFIER, 1563 PROVIDER_AGREEMENT_IDENTIFIER, and NONCE as those used when creating 1564 the order. 1566 Upon receipt of a WITHDRAW message, the server checks whether an 1567 order matching the request is found. If an order is found, the state 1568 of the order is changed to "Cancelled" and an ACK message including 1569 an Empty CPD is returned to the requesting client. If no order is 1570 found, the server returns a FAIL message to the requesting client. 1572 9.2.9. UPDATE 1574 The format of the UPDATE message is shown below: 1576 ::= 1577 1578 1579 1580 1581 1582 1583 1584 1585 [...] 1587 This message is sent by the CPNP client to update an existing 1588 connectivity provisioning agreement. The CPNP must include the same 1589 CUSTOMER_AGREEMENT_IDENTIFIER, PROVIDER_AGREEMENT_IDENTIFIER, and 1590 NONCE as those used when creating the order. The CPNP client 1591 includes a new CPD which integrates the requested modifications. A 1592 new Transaction_ID must be assigned by the client. 1594 Upon receipt of an UPDATE message, the server checks whether an 1595 order, having state "Completed", matches 1596 CUSTOMER_AGREEMENT_IDENTIFIER, PROVIDER_AGREEMENT_IDENTIFIER, and 1597 NONCE. 1599 o If no order is found, the CPNP server generates a FAIL error with 1600 the appropriate error code. 1601 o If an order is found, the server checks whether it can honor the 1602 request: 1604 * A FAIL message is sent to the client if the server cannot honor 1605 the request. The client may initiate a new PQO negotiation 1606 cycle. 1607 * An OFFER message including the updated connectivity 1608 provisioning document is sent to the client. For example, the 1609 server maintains an order for provisioning a VPN service that 1610 connects sites A, B and C. If the client sends an UPDATE 1611 message to remove site C, only sites A and B will be included 1612 in the OFFER sent by the server to the requesting client. 1614 A flow chart that illustrates the use of UPDATE operation is shown in 1615 Figure 14. 1617 +------+ +------+ 1618 |Client| |Server| 1619 +------+ +------+ 1620 |=========UPDATE(Requested CPD)======>| 1621 |<============PROCESSING==============| 1622 |<=========OFFER(Updated CPD)=========| 1623 |=============PROCESSING=============>| 1624 |==========ACCEPT(Updated CPD)=======>| 1625 |<==========ACK(Updated CPD)==========| 1627 Figure 14: UPDATE Flow Example 1629 9.2.10. FAIL 1631 The format of the FAIL message is shown below: 1633 ::= 1634 1635 1636 1637 1638 1639 1641 This message is sent in the following cases: 1643 o The server can not honor an order received from the client (i.e., 1644 received in a QUOTATION or UPDATE request). 1645 o The server encounters an error when processing a CPNP request 1646 received from the client. 1647 o The client can not grant more time to a the server. This is a 1648 response to a more time request conveyed in a PROCESSING message. 1650 The status code indicates the error code. The following codes are 1651 currently supported; other codes will be defined in future versions 1652 of the document: 1654 1 (Validation Error): The message can not be validated (see 1655 Section 10). 1656 2 (Authentication Required): the request cannot be handled because 1657 authentication is required. 1658 3 (Authorization Required): the request cannot be handled because 1659 authorization failed. 1660 4 (Administratively prohibited): the request can not be handled 1661 because of administrative policies. 1662 5 (Out of Resources): the request can not be honored because there 1663 is not enough capacity. 1664 6 (Network Presence): the request can not be honored because there 1665 is no network presence. 1666 7 (More Time Rejected): the request to extend the time negotiation 1667 is rejected by the client. 1669 10. Message Validation 1671 Both client and server proceed with CPNP message validation. The 1672 following tables summarize the validation checks to be followed. 1674 10.1. On the Client Side 1675 Operation Validation Checks 1676 ------------ -------------------------------------------------------- 1677 PROCESSING {Source IP address, source port, destination IP address, 1678 destination port, Transaction-ID, Customer Order 1679 Identifier} must match an existing PQO with a state set 1680 to "PQOSent". The sequence number carried in the packet 1681 must be larger than the sequence number maintained by 1682 the client. 1683 OFFER {Source IP address, source port, destination IP address, 1684 destination port, Transaction-ID, Customer Order 1685 Identifier} must match an existing order with state set 1686 to "PQOSent" or {Source IP address, source port, 1687 destination IP address, destination port, Transaction- 1688 ID, Customer Order Identifier, Provider Order 1689 Identifier} must match an existing order with a state 1690 set to "ServerProcessing". The sequence number carried 1691 in the packet must be larger than the sequence number 1692 maintained by the client. 1693 ACK {Source IP address, source port, destination IP address, 1694 (QUOTATION destination port, Transaction-ID, Customer Order 1695 Transaction) Identifier, Provider Order Identifier, Offered 1696 Connectivity Provisioning Order} must match an order 1697 with a state set to "AcceptSent". The sequence number 1698 carried in the packet must be larger than the sequence 1699 number maintained by the client. 1700 ACK (UPDATE {Source IP address, source port, destination IP address, 1701 Transaction) destination port, Transaction-ID, Customer Order 1702 Identifier, Provider Order Identifier, Updated 1703 Connectivity Provisioning Order} must match an order 1704 with a state set to "AcceptSent". The sequence number 1705 carried in the packet must be larger than the sequence 1706 number maintained by the client. 1707 ACK {Source IP address, source port, destination IP address, 1708 (WITHDRAW destination port, Transaction-ID, Customer Order 1709 Transaction) Identifier, Provider Order Identifier, Empty 1710 Connectivity Provisioning Order} must match an order 1711 with a state set to "Cancelled". The sequence number 1712 carried in the packet must be larger than the sequence 1713 number maintained by the client. 1715 10.2. On the Server Side 1716 Method Validation Checks 1717 ---------- ---------------------------------------------------------- 1718 QUOTATION The source IP address passes existing access filters (if 1719 any). The sequence number carried in the packet must not 1720 be less than the sequence number maintained by the server. 1721 PROCESSING The sequence number carried in the packet must be larger 1722 than the sequence number maintained by the server. 1723 ACCEPT {Source IP address, source port, destination IP address, 1724 destination port, Transaction-ID, Customer Order 1725 Identifier, Provider Order Identifier, Nonce, Offered 1726 Connectivity Provisioning Order} must match an order with 1727 state set to "OfferProposed" or "ProcessngReceived". The 1728 sequence number carried in the packet must be larger than 1729 the sequence number maintained by the server. 1730 DECLINE {Source IP address, source port, destination IP address, 1731 destination port, Transaction-ID, Customer Order 1732 Identifier, Provider Order Identifier, Nonce} must match 1733 an order with state set to "OfferProposed" or 1734 "ProcessngReceived". The sequence number carried in the 1735 packet must be larger than the sequence number maintained 1736 by the server. 1737 UPDATE The source IP address passes existing access filters (if 1738 any) and {Customer Order Identifier, Provider Order 1739 Identifier, Nonce} must match an existing order with state 1740 "Completed". 1741 WITHDRAW The source IP address passes existing access filters (if 1742 any) and {Customer Order Identifier, Provider Order 1743 Identifier, Nonce} must match an existing order with state 1744 "Completed". 1746 11. Theory of Operation 1748 Both CPNP client and server proceeds to message validation checks as 1749 specified in Section 10. 1751 11.1. Client Behavior 1753 11.1.1. Order Negotiation Cycle 1755 To place a provisioning quotation order, the client initiates first a 1756 local quotation order object identified by a unique identifier 1757 assigned by the client. The state of the quotation order is set to 1758 "Created". The client then generates a QUOTATION request which 1759 includes the assigned identifier, possibly an expected response time, 1760 a Transaction-ID and a Requested Connectivity Provisioning Document. 1761 The client may include additional Information Elements such as 1762 Negotiation Options. 1764 The client may be configured to not enforce negotiation checks on 1765 EXPECTED_OFFER_TIME; if so no EXPECTED_RESPONSE_TIME attribute (or 1766 EXPECTED_RESPONSE_TIME set to infinite) should be included in the 1767 quotation order. 1769 Once the request is sent to the server, the state of the request is 1770 set to "PQOSent" and a timer, if a response time is included in the 1771 quotation order, is set to the expiration time as included in the 1772 QUOTATION request. The client also maintains a copy of the extended 1773 transport session details used to generate the QUOTATION request. 1774 The CPNP client must listen on the same port number that it used to 1775 send the QUOTATION request. 1777 If no answer is received from the server before the retransmission 1778 timer expires (i.e., RETRANS_TIMER, Section 8.7), the client proceeds 1779 to retransmission until maximum retry is reached (i.e., 3 times). 1780 The same sequence number is used for retransmitted packets. 1782 If a FAIL message is received, the client may decide to issue another 1783 (corrected) request towards the same server, cancel the local order, 1784 or contact another server. The behavior of the client depends on the 1785 error code returned by the server in the FAIL message. 1787 If a PROCESSING message matching the CPNP transport session is 1788 received, the client updates the CPNP session with the 1789 PROVIDER_AGREEMENT_IDENTIFIER information. If the client does not 1790 accept the expected offer time that may have been indicated in the 1791 PROCESSING message, the client may decide to cancel the quotation 1792 order. If the client accepts the EXPECTED_OFFER_TIME, it changes the 1793 state of the order to "ServerProcessing" and sets a timer to the 1794 value of EXPECTED_OFFER_TIME. If no offer is made before the timer 1795 expires, the client changes the state of the order to "Cancelled". 1797 As a response to a more time request (conveyed in a PROCESSING 1798 message that included a new EXPECTED_OFFER_TIME), the client may 1799 grant this extension by issuing an ACK message or reject the time 1800 extension with a FAIL message having a status code set to "More Time 1801 Rejected". 1803 If an OFFER message matching the extended CPNP session is received, 1804 the client checks if a PROCESSING message having the same 1805 PROVIDER_AGREEMENT_IDENTIFIER has been received from the server. If 1806 a PROCESSING message was already received for the same order but the 1807 PROVIDER_AGREEMENT_IDENTIFIER does not match the identifier included 1808 in the OFFER message, the client ignores silently the message. If a 1809 PROCESSING message having the same PROVIDER_AGREEMENT_IDENTIFIER was 1810 already received and matches the CPNP transaction identifier, the 1811 client changes the state of the order to "OfferReceived" and sets a 1812 timer to the value of VALIDITY_OFFER_TIME indicated in the OFFER 1813 message. 1815 If an offer is received from the server (i.e., as documented in an 1816 OFFER message), the client may accept or reject the offer. The 1817 client accepts the offer by generating an ACCEPT message which 1818 confirms that the client agrees to subscribe to the offer documented 1819 in the OFFER message; the state of the order is passed to 1820 "AcceptSent". The transaction is terminated if an ACK message is 1821 received from the server. If no ACK is received from the server, the 1822 client proceeds with the re-transmission of the ACCEPT message. 1824 The client may also decide to reject the offer by sending a DECLINE 1825 message. The state of the order is set by the client to "Cancelled". 1826 If an offer is not acceptable by the client, the client may decide to 1827 contact a new server or submit another order to the same server. 1828 Guidelines to issue an updated order or terminate the negotiation are 1829 specific to the client. 1831 11.1.2. Order Withdrawal Cycle 1833 A client may withdraw a completed order. This is achieved by issuing 1834 a WITHDRAW message. This message must include Customer Order 1835 Identifier, Provider Identifier and Nonce returned during the order 1836 negotiation cycle specified in Section 11.1.1. 1838 If no ACK is received from the server, the client proceeds with the 1839 re-transmission of the message. 1841 11.1.3. Order Update Cycle 1843 A client may update a completed order. This is achieved by issuing 1844 an UPDATE message. This message must include Customer Order 1845 Identifier, Provider Order Identifier and Nonce returned during the 1846 order negotiation cycle specified in Section 11.1.1. The client must 1847 include in the UPDATE message an updated CPD with the requested 1848 changes. 1850 Subsequent messages exchange is similar to what is documented in 1851 Section 11.1.1. 1853 11.2. Server Behavior 1855 11.2.1. Order Processing 1857 Upon receipt of a QUOTATION message from a client, the server sets a 1858 CPNP session, stores Transaction-ID and generates a Provider Order 1859 Identifier. Once preliminary validation checks are completed ( 1860 Section 10), the server may return a PROCESSING message to notify the 1861 client the quotation order is received and it is under processing; 1862 the server may include an expected offer time to notify the client by 1863 when an offer will be proposed. An order with state 1864 "AwaitingProcessing" is created by the server. The server runs its 1865 decision-making process to decide which offer it can make to honor 1866 the received order. The offer should be made before the expected 1867 offer time expires. 1869 If the server cannot make an offer, it sends backs a FAIL message 1870 with the appropriate error code. 1872 If the server requires more negotiation time, it must send a 1873 PROCESSING message with a new EXPECTED_OFFER_TIME. The client may 1874 grant this extension by issuing an ACK message or reject the time 1875 extension with a FAIL message having a status code set to "More Time 1876 Rejected". If the client doesn't grant more time, the server must 1877 answer before the initial expected offer time; otherwise the client 1878 will ignore the quotation order. 1880 If the server can honor the request or it can make an offer that meet 1881 some of the requirements, it creates an OFFER message. The server 1882 must indicate the Transaction-ID, Customer Order Identifier as 1883 indicated in the QUOTATION message, and the Provider Order Identifier 1884 generated for this order. The server must also include Nonce and the 1885 offered Connectivity Provisioning Document. The server includes an 1886 offer validity time as well. Once sent to the client, the server 1887 changes the state of the order to "OfferSent" and a timer set to the 1888 validity time is initiated. 1890 If the server determines that additional network resources from 1891 another network provider are needed to accommodate a quotation order, 1892 it will create child PQO(s) and will behave as a CPNP client to 1893 negotiate child PQO(s) with possible partnering providers (see 1894 Figure 6). 1896 If no PROCESSING, ACCEPT or DECLINE message is received before the 1897 expiry of the RETRANS_TIMER, the server re-sends the same offer to 1898 the client. This procedure is repeated until maximum retry is 1899 reached. 1901 If an ACCEPT message is received before the offered validity time 1902 expires, the server proceeds with validation checks as specified in 1903 Section 10. The state of the corresponding order is passed to 1904 "AcceptReceived". The server sends back an ACK message to terminate 1905 the order processing cycle. 1907 If a CANCEL/DECLINE message is received, the server proceeds with the 1908 cancellation of the order. The state of the order is then passed to 1909 "Cancelled". 1911 11.2.2. Order Withdrawal 1913 A client may withdraw a completed order by issuing a WITHDRAW 1914 message. Upon receipt of a WITHDRAW message, the server proceeds 1915 with the validation checks, as specified in Section 10. 1917 o If the checks fail, a FAIL message is sent back to the client with 1918 the appropriate error code. 1920 o If the checks succeed, the server clears the clauses of the 1921 Connectivity Provisioning Document, changes the state of the order 1922 to "Cancelled", and sends back an ACK message with an Empty 1923 Connectivity Provisioning Document. 1925 11.2.3. Order Update 1927 A client may update an order by issuing an UPDATE message. Upon 1928 receipt of an UPDATE message, the server proceeds with the validation 1929 checks as specified in Section 10. 1931 o If the checks fail, a FAIL message is sent back to the client with 1932 the appropriate error code. 1933 o Subsequent messages exchange is similar to what is specified in 1934 Section 11.1.1. The server should generate a new Nonce value to 1935 be included in the offer made to the client. 1937 11.3. Sequence Numbers 1939 In each transaction, sequence numbers are used to protect the 1940 transaction against replay attacks. Each communicating partner of 1941 the transaction maintains two sequence numbers, one for incoming 1942 packets and one for outgoing packets. When a partner receives a 1943 message, it will check whether the sequence number in the message is 1944 larger than the incoming sequence number maintained locally. If not, 1945 the messages will be discarded. If the message is proved to be 1946 legal, the value of the incoming sequence number will be replaced by 1947 the value of the sequence number in the message. When a partner 1948 sends out a message, it will insert the value of outgoing sequence 1949 number into the message and increase the outgoing sequence number 1950 maintained locally by 1. 1952 11.4. Message Re-Transmission 1954 If a transaction partner sends out a message and does not receive any 1955 expected reply before the retransmission timer expires (i.e., 1956 RETRANS_TIMER), a transaction partner will try to re-transit the 1957 messages. An exception is the last message (e.g., ACK) sent from the 1958 server in a transaction. After sending this message, the 1959 retransmission timer will be disabled since no additional feedback is 1960 expected. 1962 In addition, if the partner receives a re-sent last incoming packet, 1963 the partner can also send out the answer to the incoming packet with 1964 a limited frequency. If no answer was generated at the moment, the 1965 partner needs to generate a PROCESSING message as the answer. 1967 To benefit message re-transmission, a partner could also store the 1968 last incoming packet and the associated answer. Note that the times 1969 of re-transmission could be decided by the local policy and re- 1970 transmission will not cause any change of sequence numbers. 1972 12. Operational Guidelines 1974 12.1. Logging on the CPNP Server 1976 The CPNP server SHOULD be configurable to log various events and 1977 associated information. Such information includes: 1979 o Client's IP address 1980 o Any event change (e.g., new quotation order, offer sent, order 1981 confirm, order cancellation, order withdraw, etc.) 1982 o Timestamp 1984 12.2. Business Guidelines & Objectives 1986 The CPNP server can operate in the following modes: 1988 1. Fully automated mode: The CPNP server is provisioned with a set 1989 of business guidelines and objectives that will be used as an 1990 input to the decision-making process. The CPNP server will 1991 service received orders that falls into these business 1992 guidelines; otherwise requests will be escalated to an 1993 administrator that will formally validate/invalidate an order 1994 request. The set of policies to be configured to the CPNP server 1995 are specific to each administrative entity managing a CPNP 1996 server. 1998 2. Administrative-based mode: This mode assumes some or all CPNP 1999 server' operations are subject to a formal administrative 2000 validation. CPNP events will trigger appropriate validation 2001 requests that will be forwarded to the contact person(s) or 2002 department which is responsible for validating the orders. 2003 Administrative validation messages are relayed using another 2004 protocol (e.g., SMTP) or a dedicated tool. 2006 Business guidelines are local to each administrative entity. How 2007 validation requests are presented to an administrator are out of 2008 scope of this document; each administrative entity may decide the 2009 appropriate mechanism to enable for that purpose. 2011 13. Security Considerations 2013 Means to defend the server against denial-of-service attacks must be 2014 enabled. For example, access control lists (ACLs) can be enforced on 2015 the client, the server or the network in between, to allow a trusted 2016 client to communicate with a trusted server. 2018 The client and the server should be mutually authenticated. Out of 2019 band mechanisms can be used instead of integrating them into CPNP. 2021 The client must silently discard CPNP responses received from unknown 2022 CPNP servers. The use of a randomly generated Transaction-ID makes 2023 it hard to forge a response from a server with a spoofed IP address 2024 belonging to a legitimate CPNP server. Furthermore, CPNP demands 2025 that messages from the server must include correct identifiers of the 2026 orders. Two order identifiers are used: one generated by the client 2027 and a second one generated by the server. 2029 The Provider must enforce means to protect privacy-related 2030 information included the documents (see Section 8.9) exchanged using 2031 CPNP messages [RFC6462]. In particular, this information must not be 2032 revealed to external parties without the consent of Customers. 2033 Providers should enforce policies to make Customer fingerprinting 2034 difficult to achieve. For more discussion about privacy, refer to 2035 [RFC6462][RFC6973]. 2037 The NONCE and the Transaction ID attributes provide sufficient 2038 randomness and can effectively tolerate attacks raised by off-line 2039 adversaries, who do not have the capability of eavesdropping and 2040 intercepting the packets transported between the client and the 2041 server. Only authorized clients must be able to modify agreed CPNP 2042 orders. The use of a randomly generated NONCE by the server makes it 2043 hard to modify an agreement on behalf of a malicious third-party. 2045 The sequence numbers included in the CPNP messages can be used to 2046 detect replay attacks and antique packets intercepted from on-going 2047 transactions may be re-sent. However, the protocol in its current 2048 version may be vulnerable to replay attacks where the replayed 2049 messages are intercepted from antique transactions. Although the 2050 Transaction ID provided by the client could protect inter-transaction 2051 replay attacks, no protection is provided for the server to deal with 2052 this type of attack. 2054 The protocol does not provide security mechanisms to protect the 2055 confidentiality and integrity of the packets transported between the 2056 client and the server. An underlying security protocol such as 2057 (e.g., DTLS [RFC6347], IPsec) could be used to protect the integrity 2058 and confidentiality for the protocol. In this case, if it is 2059 possible to provide an Automated Key Management (AKM) and associate 2060 each transaction with a different key, inter- transaction replay 2061 attacks can naturally be addressed. If the client and the server use 2062 a single key, an additional mechanism should be provided to protect 2063 inter-transaction replay attacks between them. 2065 The deployment option of a Customer Order Management portal operated 2066 by a trusted third-party (see Section 6) may facilitate the efficient 2067 resolution of the aforementioned security concerns. 2069 14. IANA Considerations 2071 Authors of the document request IANA to assign a UDP port for CPNP. 2073 A registry for CPNP methods should be created. The following initial 2074 codes should be reserved: 2076 1: QUOTATION 2077 2: PROCESSING 2078 3: OFFER 2079 4: ACCEPT 2080 5: DECLINE 2081 6: ACK 2082 7: CANCEL 2083 8: WITHDRAW 2084 9: UPDATE 2085 10: FAIL 2087 A registry for CPNP error codes should be created. The following 2088 initial error codes should be reserved: 2090 1: Message Validation Error 2091 2: Authentication Required 2092 3: Authorization Failed 2093 4: Administratively prohibited 2094 5: Out of Resources 2095 6: Network Presence Error 2096 7: More Time Rejected 2098 15. Acknowledgements 2100 Thanks to Diego R. Lopez for his comments. 2102 16. References 2104 16.1. Normative References 2106 [RFC1123] Braden, R., Ed., "Requirements for Internet Hosts - 2107 Application and Support", STD 3, RFC 1123, 2108 DOI 10.17487/RFC1123, October 1989, 2109 . 2111 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 2112 Requirement Levels", BCP 14, RFC 2119, 2113 DOI 10.17487/RFC2119, March 1997, 2114 . 2116 [RFC4086] Eastlake 3rd, D., Schiller, J., and S. Crocker, 2117 "Randomness Requirements for Security", BCP 106, RFC 4086, 2118 DOI 10.17487/RFC4086, June 2005, 2119 . 2121 [RFC5511] Farrel, A., "Routing Backus-Naur Form (RBNF): A Syntax 2122 Used to Form Encoding Rules in Various Routing Protocol 2123 Specifications", RFC 5511, DOI 10.17487/RFC5511, April 2124 2009, . 2126 16.2. Informative References 2128 [ETICS] EU FP7 ETICS Project, "Economics and Technologies of 2129 Inter-Carrier Services", January 2014, . 2133 [I-D.boucadair-lisp-idr-ms-discovery] 2134 Boucadair, M. and C. Jacquenet, "LISP Mapping Service 2135 Discovery at Large", draft-boucadair-lisp-idr-ms- 2136 discovery-01 (work in progress), March 2016. 2138 [RFC2782] Gulbrandsen, A., Vixie, P., and L. Esibov, "A DNS RR for 2139 specifying the location of services (DNS SRV)", RFC 2782, 2140 DOI 10.17487/RFC2782, February 2000, 2141 . 2143 [RFC4026] Andersson, L. and T. Madsen, "Provider Provisioned Virtual 2144 Private Network (VPN) Terminology", RFC 4026, 2145 DOI 10.17487/RFC4026, March 2005, 2146 . 2148 [RFC4176] El Mghazli, Y., Ed., Nadeau, T., Boucadair, M., Chan, K., 2149 and A. Gonguet, "Framework for Layer 3 Virtual Private 2150 Networks (L3VPN) Operations and Management", RFC 4176, 2151 DOI 10.17487/RFC4176, October 2005, 2152 . 2154 [RFC6347] Rescorla, E. and N. Modadugu, "Datagram Transport Layer 2155 Security Version 1.2", RFC 6347, DOI 10.17487/RFC6347, 2156 January 2012, . 2158 [RFC6462] Cooper, A., "Report from the Internet Privacy Workshop", 2159 RFC 6462, DOI 10.17487/RFC6462, January 2012, 2160 . 2162 [RFC6574] Tschofenig, H. and J. Arkko, "Report from the Smart Object 2163 Workshop", RFC 6574, DOI 10.17487/RFC6574, April 2012, 2164 . 2166 [RFC6770] Bertrand, G., Ed., Stephan, E., Burbridge, T., Eardley, 2167 P., Ma, K., and G. Watson, "Use Cases for Content Delivery 2168 Network Interconnection", RFC 6770, DOI 10.17487/RFC6770, 2169 November 2012, . 2171 [RFC6793] Vohra, Q. and E. Chen, "BGP Support for Four-Octet 2172 Autonomous System (AS) Number Space", RFC 6793, 2173 DOI 10.17487/RFC6793, December 2012, 2174 . 2176 [RFC6830] Farinacci, D., Fuller, V., Meyer, D., and D. Lewis, "The 2177 Locator/ID Separation Protocol (LISP)", RFC 6830, 2178 DOI 10.17487/RFC6830, January 2013, 2179 . 2181 [RFC6973] Cooper, A., Tschofenig, H., Aboba, B., Peterson, J., 2182 Morris, J., Hansen, M., and R. Smith, "Privacy 2183 Considerations for Internet Protocols", RFC 6973, 2184 DOI 10.17487/RFC6973, July 2013, 2185 . 2187 [RFC7149] Boucadair, M. and C. Jacquenet, "Software-Defined 2188 Networking: A Perspective from within a Service Provider 2189 Environment", RFC 7149, DOI 10.17487/RFC7149, March 2014, 2190 . 2192 [RFC7297] Boucadair, M., Jacquenet, C., and N. Wang, "IP 2193 Connectivity Provisioning Profile (CPP)", RFC 7297, 2194 DOI 10.17487/RFC7297, July 2014, 2195 . 2197 Authors' Addresses 2199 Mohamed Boucadair 2200 Orange 2201 Rennes 35000 2202 France 2204 Email: mohamed.boucadair@orange.com 2206 Christian Jacquenet 2207 Orange 2208 Rennes 35000 2209 France 2211 Email: christian.jacquenet@orange.com 2213 Dacheng Zhang 2214 Huawei Technologies 2216 Email: zhangdacheng@huawei.com 2218 Panos Georgatsos 2219 Centre for Research and Innovation Hellas 2220 78, Filikis Etairias str. 2221 Volos, Hellas 38334 2222 Greece 2224 Phone: +302421306070 2225 Email: pgeorgat@iti.gr