Network Working Group                                       M. Boucadair
Internet-Draft                                              C. Jacquenet
Intended status: Experimental                                     Orange
Expires: September 15, 2016                                     D. Zhang
                                                     Huawei Technologies
                                                           P. Georgatsos
                                                                   CERTH
                                                          March 14, 2016


         Connectivity Provisioning Negotiation Protocol (CPNP)
         draft-boucadair-connectivity-provisioning-protocol-11

Abstract

   This document specifies the Connectivity Provisioning Negotiation
   Protocol (CPNP) which is used for dynamic negotiation of service
   parameters.

   CPNP is a generic protocol that can be used for various negotiation
   purposes that include (but are not necessarily limited to)
   connectivity provisioning services, storage facilities, Content
   Delivery Networks footprint, etc.  The protocol can be extended with
   new Information Elements.

Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119 [RFC2119].

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on September 15, 2016.




Boucadair, et al.      Expires September 15, 2016               [Page 1]


Internet-Draft                    CPNP                        March 2016


Copyright Notice

   Copyright (c) 2016 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . .   5
   3.  CPNP Functional Elements  . . . . . . . . . . . . . . . . . .   6
   4.  Order Processing Models . . . . . . . . . . . . . . . . . . .   6
   5.  Sample Use Cases  . . . . . . . . . . . . . . . . . . . . . .   8
   6.  CPNP Deployment Models  . . . . . . . . . . . . . . . . . . .  10
   7.  CPNP Negotiation Model  . . . . . . . . . . . . . . . . . . .  10
   8.  Protocol Overview . . . . . . . . . . . . . . . . . . . . . .  13
     8.1.  Client/Server Communication . . . . . . . . . . . . . . .  13
     8.2.  Server Discovery  . . . . . . . . . . . . . . . . . . . .  13
     8.3.  Policy Configuration on the CPNP Server . . . . . . . . .  13
     8.4.  CPNP Session  . . . . . . . . . . . . . . . . . . . . . .  15
     8.5.  Extended CPNP Session . . . . . . . . . . . . . . . . . .  15
     8.6.  CPNP Transaction  . . . . . . . . . . . . . . . . . . . .  16
     8.7.  CPNP Timers . . . . . . . . . . . . . . . . . . . . . . .  16
     8.8.  CPNP Operations . . . . . . . . . . . . . . . . . . . . .  16
     8.9.  Connectivity Provisioning Documents . . . . . . . . . . .  18
     8.10. Child Provisioning Quotation Orders . . . . . . . . . . .  19
     8.11. Negotiations with Multiple CPNP Servers . . . . . . . . .  20
     8.12. State Management  . . . . . . . . . . . . . . . . . . . .  20
       8.12.1.  On the Client Side . . . . . . . . . . . . . . . . .  21
       8.12.2.  On the Server Side . . . . . . . . . . . . . . . . .  23
   9.  CPNP Objects  . . . . . . . . . . . . . . . . . . . . . . . .  25
     9.1.  Attributes  . . . . . . . . . . . . . . . . . . . . . . .  25
       9.1.1.  CUSTOMER_AGREEMENT_IDENTIFIER . . . . . . . . . . . .  25
       9.1.2.  PROVIDER_AGREEMENT_IDENTIFIER . . . . . . . . . . . .  25
       9.1.3.  TRANSACTION_ID  . . . . . . . . . . . . . . . . . . .  26
       9.1.4.  SEQUENCE_NUMBER . . . . . . . . . . . . . . . . . . .  26
       9.1.5.  NONCE . . . . . . . . . . . . . . . . . . . . . . . .  26
       9.1.6.  EXPECTED_RESPONSE_TIME  . . . . . . . . . . . . . . .  26
       9.1.7.  EXPECTED_OFFER_TIME . . . . . . . . . . . . . . . . .  26



Boucadair, et al.      Expires September 15, 2016               [Page 2]


Internet-Draft                    CPNP                        March 2016


       9.1.8.  VALIDITY_OFFER_TIME . . . . . . . . . . . . . . . . .  27
       9.1.9.  CONNECTIVITY_PROVISIONING_DOCUMENT  . . . . . . . . .  27
       9.1.10. Information Elements  . . . . . . . . . . . . . . . .  27
     9.2.  Operation Messages  . . . . . . . . . . . . . . . . . . .  29
       9.2.1.  QUOTATION . . . . . . . . . . . . . . . . . . . . . .  29
       9.2.2.  PROCESSING  . . . . . . . . . . . . . . . . . . . . .  29
       9.2.3.  OFFER . . . . . . . . . . . . . . . . . . . . . . . .  31
       9.2.4.  ACCEPT  . . . . . . . . . . . . . . . . . . . . . . .  31
       9.2.5.  ACK . . . . . . . . . . . . . . . . . . . . . . . . .  31
       9.2.6.  DECLINE . . . . . . . . . . . . . . . . . . . . . . .  32
       9.2.7.  CANCEL  . . . . . . . . . . . . . . . . . . . . . . .  33
       9.2.8.  WITHDRAW  . . . . . . . . . . . . . . . . . . . . . .  33
       9.2.9.  UPDATE  . . . . . . . . . . . . . . . . . . . . . . .  34
       9.2.10. FAIL  . . . . . . . . . . . . . . . . . . . . . . . .  35
   10. Message Validation  . . . . . . . . . . . . . . . . . . . . .  36
     10.1.  On the Client Side . . . . . . . . . . . . . . . . . . .  36
     10.2.  On the Server Side . . . . . . . . . . . . . . . . . . .  37
   11. Theory of Operation . . . . . . . . . . . . . . . . . . . . .  38
     11.1.  Client Behavior  . . . . . . . . . . . . . . . . . . . .  38
       11.1.1.  Order Negotiation Cycle  . . . . . . . . . . . . . .  38
       11.1.2.  Order Withdrawal Cycle . . . . . . . . . . . . . . .  40
       11.1.3.  Order Update Cycle . . . . . . . . . . . . . . . . .  40
     11.2.  Server Behavior  . . . . . . . . . . . . . . . . . . . .  40
       11.2.1.  Order Processing . . . . . . . . . . . . . . . . . .  40
       11.2.2.  Order Withdrawal . . . . . . . . . . . . . . . . . .  42
       11.2.3.  Order Update . . . . . . . . . . . . . . . . . . . .  42
     11.3.  Sequence Numbers . . . . . . . . . . . . . . . . . . . .  42
     11.4.  Message Re-Transmission  . . . . . . . . . . . . . . . .  43
   12. Operational Guidelines  . . . . . . . . . . . . . . . . . . .  43
     12.1.  Logging on the CPNP Server . . . . . . . . . . . . . . .  43
     12.2.  Business Guidelines & Objectives . . . . . . . . . . . .  43
   13. Security Considerations . . . . . . . . . . . . . . . . . . .  44
   14. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  45
   15. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  46
   16. References  . . . . . . . . . . . . . . . . . . . . . . . . .  46
     16.1.  Normative References . . . . . . . . . . . . . . . . . .  46
     16.2.  Informative References . . . . . . . . . . . . . . . . .  46
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  48

1.  Introduction

   This document defines the Connectivity Provisioning Negotiation
   Protocol (CPNP) that is meant to dynamically exchange and negotiate
   connectivity provisioning parameters, and other service-specific
   parameters, between a Customer and a Provider.  CPNP is a tool that
   introduces automation in the service negotiation and activation
   procedures, thus fostering the overall service provisioning process.




Boucadair, et al.      Expires September 15, 2016               [Page 3]


Internet-Draft                    CPNP                        March 2016


   CPNP can be seen as a component of the dynamic negotiation meta-
   domain described in Section 3.4 of [RFC7149].

   CPNP is a generic protocol that can be used for other negotiation
   purposes than connectivity provisioning.  For example, CPNP can be
   used to request extra storage resources, to extend the footprint of a
   CDN (Content Delivery Networks), to enable additional features from a
   cloud Provider, etc.  CPNP can be extended with new Information
   Elements (IEs).

   [RFC7297] describes a Connectivity Provisioning Profile (CPP)
   template to capture connectivity requirements to be met by a
   transport infrastructure for the delivery of various services such as
   Voice over IP (VoIP), IPTV, and Virtual Private Network (VPN)
   services [RFC4026].  The CPP document defines the set of IP transfer
   parameters that reflect the guarantees that can be provided by the
   underlying transport network together with reachability scope and
   capacity needs.  CPNP uses the CPP template to encode connectivity
   provisioning clauses.

   As a reminder, several proposals have been made in the past by the
   (research) community (e.g., COPS-SLS, Service Negotiation Protocol
   (SrNP), Dynamic Service Negotiation Protocol (DSNP), Resource
   Negotiation and Pricing Protocol (RNAP), Service Negotiation and
   Acquisition Protocol (SNAP), etc.).  It is out of the scope of this
   document to elaborate on the differences between CPNP and the
   aforementioned proposals.

   This document is organized as follows:

   o  Section 3 defines the functional elements involved in CPNP
      exchanges.
   o  Section 4 introduces several order processing models and precises
      those that are targeted by CPNP.
   o  Section 5 enumerates a non-exhaustive list of use cases that could
      benefit from CPNP.
   o  Section 5 discusses CPNP deployment models.
   o  Section 7 presents the CPNP negotiation model.
   o  Section 8 provides an overview of the protocol.
   o  Section 9 specifies the CPNP objects.
   o  Section 10 describes the CPNP message validation procedure.
   o  Section 11 specifies the behavior of the involved CPNP functional
      elements.
   o  Section 12 discusses relevant operational guidelines.
   o  Section 13 discusses protocol security aspects.






Boucadair, et al.      Expires September 15, 2016               [Page 4]


Internet-Draft                    CPNP                        March 2016


2.  Terminology

   This document makes use of the following terms:

   o  Customer: Is a business role which denotes an entity that is
      involved in the definition and the possible negotiation of a
      contract, including a Connectivity Provisioning Agreement, with a
      Provider.  A connectivity provisioning contract is captured in a
      dedicated CPP template-based document, which specifies (among
      other information): the sites to be connected, border nodes,
      outsourced operations (e.g., routing, force via points).

      The right to invoke the subscribed service may be delegated by the
      Customer to third-party End Users, or brokering services.

      A Customer can be a Service Provider, an application owner, an
      enterprise, a user, etc.

   o  Network Provider (or Provider): Owns and administers one or many
      transport domain(s) (typically Autonomous System (AS)) composed of
      IP switching and transmission resources (e.g., routing, switching,
      forwarding, etc.).  Network Providers are responsible for ensuring
      connectivity services (e.g., offering global or restricted
      reachability at specific rates).  Offered connectivity services
      may not necessarily be restricted to IP.

      The policies to be enforced by the connectivity service delivery
      components can be derived from the technology-specific clauses
      that might be included in contracts agreed with the Customers.  If
      no such clauses are included in the agreement, the mapping between
      the connectivity requirements and the underlying technology-
      specific policies to be enforced is deployment-specific.

   o  Quotation Order: Denotes a request made by the Customer to the
      Provider that includes a set of requirements.  The Customer may
      express its service-specific requirements by assigning (fixed or
      loosely defined) values to the information items included in the
      commonly understood template (e.g., CPP template) describing the
      offered service.  These requirements constitute the parameters to
      be mutually agreed upon.

   o  Offer: Refers to a response made by the Provider to a Customer 's
      quotation order as to the extent at which the Provider may satisfy
      the order at the time of its receipt.  Offers reflect the
      capability of the Provider in accommodating received Customer
      orders beyond monolithic 'yes/no' answers.





Boucadair, et al.      Expires September 15, 2016               [Page 5]


Internet-Draft                    CPNP                        March 2016


      An offer may fully or partially meet the requirements of the
      corresponding order.  In the latter case, it may include
      alternative suggestions which the Customer may take into account
      by issuing a new order.

   o  Agreement: Refers to an order placed by the Customer and accepted
      by the Provider.  It signals the successful conclusion of a
      negotiation cycle.

3.  CPNP Functional Elements

   The following functional elements are defined:

   o  CPNP client (or client): Denotes a software instance that sends
      CPNP requests and receives CPNP responses.  The current operations
      that can be performed by a CPNP client are listed below:

      1.  Create a quotation order (Section 11.1.1).

      2.  Cancel an ongoing quotation order under negotiation
          (Section 11.1.1).

      3.  Accept an offer made by a server (Section 11.1.1).

      4.  Withdraw an agreement (Section 11.1.2).

      5.  Update an agreement (Section 11.1.3).

   o  CPNP server (or server): Denotes a software instance that receives
      CPNP requests and sends back CPNP responses accordingly.  The CPNP
      server is responsible for the following operations:

      1.  Process a quotation order (Section 11.2.1).

      2.  Make an offer (Section 11.2.1).

      3.  Cancel an ongoing quotation order (Section 11.2.2).

      4.  Process an order withdrawal (Section 11.2.3).

4.  Order Processing Models

   For preparing their service orders, the Customers may need to be
   aware of the offered services.  The Providers therefore should first
   proceed with the announcement of the services that they can provide.
   The service announcement process may take place at designated global
   or Provider-specific service markets, or through explicit




Boucadair, et al.      Expires September 15, 2016               [Page 6]


Internet-Draft                    CPNP                        March 2016


   interactions with the Providers.  The details of this process are
   outside the scope of a negotiation protocol.

   With or without such service announcement mechanisms in place, the
   following order processing models can be distinguished:

   The following order processing models can be distinguished:

   1.  Frozen model: The Customer cannot actually negotiate the
       parameters of the service(s) offered by a Provider.  After
       consulting the Provider's service portfolio, the Customer selects
       the service offer he/she wants to subscribe and places an order
       to the Provider.  Order handling is quite simple on the Provider
       side because the service is not customized as per Customer's
       requirements, but rather pre-designed to target a group of
       customers having similar requirements (i.e., these customers
       share the same Customer Provisioning Profile).

   2.  Negotiation-based model: Unlike the frozen model, the Customer
       documents his/her requirements in a request for a quotation,
       which is then sent to one or several Providers.  Solicited
       Providers check whether they can address these requirements or
       not, and get back to the Customer accordingly, possibly with an
       offer that may not exactly match customer's requirements (e.g., a
       100 Mbps connection cannot be provisioned given the amount of
       available resources, but an 80 Mbps connection can be provided).
       A negotiation between the Customer and the Provider(s) then
       follows to the end of reaching an agreement.

   Both frozen and negotiation-based models require the existence of
   appropriate service templates like a CPP template and their
   instantiation for expressing specific offerings from Providers and
   service requirements from Customers, respectively.  CPNP can be used
   in either model for automating the required Customer-Provider
   interactions.  Since the frozen model can be seen as a special case
   of the negotiation-based model, not only 'yes/no' answers but also
   counter offers may be issued by the Provider in response to Customer
   orders, this document focuses on the negotiation-based model.

   Order processing management on the Network Provider's side is usually
   connected with the following functional blocks:

   o  Network Provisioning (including Order Activation, Network
      Planning, etc.)
   o  Authentication, Authorization and Accounting (AAA)
   o  Network and service management (performance verification,
      complaint analysis, etc.)




Boucadair, et al.      Expires September 15, 2016               [Page 7]


Internet-Draft                    CPNP                        March 2016


   o  Sales-related functional blocks (e.g., billing, invoice
      validation, etc.)
   o  Network Impact Analysis

   CPNP does not assume any specific knowledge about these functional
   blocks, drawing an explicit line between protocol operation and the
   logic for handling connectivity provisioning requests.  Evidently
   order handling logic is subject to the information manipulated by
   these blocks.  For example, the resources that can be allocated to
   accommodate Customer's requirements may depend on network
   availability estimates as calculated by the planning functions and
   related policies as well as on the number of orders to be processed
   simultaneously over a given period of time.

   This document does not elaborate on how Customers are identified and
   subsequently managed by the Provider's Information System.

5.  Sample Use Cases

   A non-exhaustive list of CPNP use cases is provided below:

   1.  [RFC4176] introduces the L3VPN Service Order Management
       functional block which is responsible for managing the requests
       initiated by the Customers and tracks the status of the
       completion of the related operations.  CPNP can be used between
       the Customer and the Provider to negotiate L3VPN service
       parameters.

       A CPNP server could therefore be part of the L3VPN Service Order
       Management functional block discussed in [RFC4176].

   2.  CPNP can be used between two adjacent domains to deliver IP
       interconnection services (e.g., enable, update, disconnect).  For
       example, two Autonomous Systems (ASes) can be connected via
       several interconnection points.  CPNP can be used between these
       ASes to upgrade existing links, request additional resources,
       provision a new interconnection point, etc.

       See for example the framework documented in [ETICS].

   3.  An integrated Provider can use CPNP to rationalize connectivity
       provisioning needs related to its service portfolio.  A CPNP
       server function is used by network operations teams.  A CPNP
       interface to invoke CPNP negotiation cycles is exposed to service
       management teams.

   4.  Service Providers can use CPNP to initiate connectivity
       provisioning requests towards a number of Network Providers so



Boucadair, et al.      Expires September 15, 2016               [Page 8]


Internet-Draft                    CPNP                        March 2016


       that to optimize the cost of delivering their services.  Although
       multiple CPNP ordering cycles can be initiated by a Service
       Provider towards multiple Network Providers, a subset of these
       orders may actually be put into effect.

       For example, a cloud Service Provider can use CPNP to request
       more resources from Network Providers.

   5.  CPNP can be used in Machine-to-Machine (M2M) environments to
       dynamically subscribe to M2M services (e.g., access to data
       retrieved by a set of sensors, extend sensor coverage, etc.).

       Also, Internet of Things (IoT, [RFC6574]) domains may rely on
       CPNP to enable dynamic provisioning of data produced by involved
       objects, according to their specific policies, to various
       external stakeholders such as data analytics and business
       intelligence companies.  Direct CPNP-based interactions between
       IoT domains and interested parties enable open access to diverse
       sets of data across the Internet, e.g., from multiple types of
       sensors, user groups and/or geographical areas.

   6.  A Provider offering cloud services can expose a CPNP interface to
       allow Customers to dynamically negotiate related service features
       such as additional storage, processing and networking resources,
       enhanced security filters, etc.

   7.  In the inter-cloud context (also called cloud of clouds or cloud
       federation), CPNP can be used to reserve external computing and
       networking resources in other cloud environments.

   8.  CDN Providers can use CPNP to extend their footprint by
       interconnecting their CDN infrastructure [RFC6770] (see
       Figure 1).



                      ,--,--,--.             ,--,--,--.
                   ,-'          `-.       ,-'          `-.
                  (CDN Provider 'A')=====(CDN Provider 'B')
                   `-.  (CDN-A) ,-'       `-. (CDN-B)  ,-'
                      `--'--'--'             `--'--'--'

                       Figure 1: CDN Interconnection

   9.  LISP ([RFC6830]) Mapping Service Providers can use CPNP to enrich
       their mapping database by interconnecting their mapping system
       (see Figure 2).  This interconnection allows to relax the
       constraints on PxTR in favour of native LISP forwarding.  Also,



Boucadair, et al.      Expires September 15, 2016               [Page 9]


Internet-Draft                    CPNP                        March 2016


       it allows to prevent fragmented LISP mapping database.  A
       framework is described in [I-D.boucadair-lisp-idr-ms-discovery].



                     ,--,--,--.             ,--,--,--.
                  ,-'          `-.       ,-'          `-.
                 (Mapping System 'A')===(Mapping System 'B')
                  `-.          ,-'       `-.           ,-'
                     `--'--'--'             `--'--'--'

                Figure 2: LISP Mapping System Interconnect

6.  CPNP Deployment Models

   Several CPNP deployment models can be envisaged.  Two examples are
   listed below:

   o  The Customer deploys a CPNP client while one or several CPNP
      servers are deployed by the Provider.
   o  The Customer does not enable any CPNP client.  The Provider
      maintains a Customer Order Management portal.  The Customer can
      initiate connectivity provisioning quotation orders via the
      portal; appropriate CPNP messages are then generated and sent to
      the relevant CPNP server.  In this model, both the CPNP client and
      CPNP server are under the responsibility of the same
      administrative entity (i.e., Network Provider).

   Once the negotiation of connectivity provisioning parameters is
   successfully concluded that is, an order has been placed by the
   Customer, the actual network provisioning operations are initiated.
   The specification of related dynamic resource allocation and policy
   enforcement schemes, as well as how CPNP servers interact with the
   network provisioning functional blocks at Provider sides are out of
   the scope of this document.

   This document does not make any assumption about the CPNP deployment
   model either.

7.  CPNP Negotiation Model

   CPNP runs between a Customer and a Provider carrying service orders
   from the Customer and respective responses from the Provider to the
   end of reaching a connectivity service provisioning agreement.  As
   the services offered by the Provider are well-described, by means of
   the CPP template, the negotiation process is essentially a value-
   settlement process, where an agreement is pursued on the values of




Boucadair, et al.      Expires September 15, 2016              [Page 10]


Internet-Draft                    CPNP                        March 2016


   the commonly understood information items (service parameters)
   included in the service description template.

   The protocol is transparent to the content that it carries and to the
   negotiation logic, at Customer and Provider sides, that manipulates
   the content.

   The protocol aims at facilitating the execution of the negotiation
   logic by providing the required generic communication primitives.

   Since negotiations are initiated and primarily driven by the
   Customer's negotiation logic, it is reasonable to assume that the
   Customer can only call for an agreement.  An implicit approach is
   adopted for not overloading the protocol with additional messages.
   In particular, the acceptance of an offer made by the Provider
   signals a call for agreement from the Customer.  Note that it is
   almost certain the Provider to accept this call since it refers to an
   offer that itself made.  Of course, at any point the Provider or the
   Customer may quit the negotiations, each on its own grounds.

   Based on the above, CPNP adopts a Quotation Order/Offer/Answer model,
   which proceeds through the following basic steps:

   1.  The client specifies its service requirements via a Provision
       Quotation Order (PQO).  The order may include fixed or loosely
       defined values in the clauses describing service provisioning
       characteristics.

   2.  The server declines the PQO, or makes an offer to address the
       requirements of the PQO, or which may suggests a counter-
       proposals that partially addresses the requirements of the PQO
       for specific requirements that cannot be accommodated.

   3.  The client either accepts or declines the offer.  Accepting the
       offer implies a call for agreement.

   Multiple instances of CPNP may run at Customer or Provider domains.
   A CPNP client may be engaged simultaneously in multiple negotiations
   with the same or different CPNP servers (parallel negotiations, see
   Section 8.11) and a CPNP server may need to negotiate with other
   Provider(s) as part of negotiations with a CPNP client (cascaded
   negotiations, see Section 8.10).

   CPNP relies on various timers to achieve its operations.  These
   timers are used to guide the negotiation logic at both CPNP client
   and CPNP server sides, particularly in cases where the CPNP client is
   involved in parallel negotiations with several CPNP servers or in
   cases where the CPNP server is, in its turn, involved in negotiations



Boucadair, et al.      Expires September 15, 2016              [Page 11]


Internet-Draft                    CPNP                        March 2016


   with other Providers for processing a given quotation order.  Related
   to the above, CPNP allows the CPNP server to request for more time.
   This request may be accepted or rejected by the CPNP client.

   Providers may need to publish available services to the Customers
   (see Section 4).  CPNP may optionally support this functionality.
   Dedicated templates can be defined for the purpose of service
   announcements, which will be used by the CPNP clients to initiate
   their CPNP negotiation cycles.

   For simplicity, a single Offer/Answer stage is assumed within one a
   CPNP negotiation cycle.  Nevertheless, as stated before, multiple
   CPNP negotiation cycles can be undertaken by a CPNP client (see
   Figure 3).

   The model is flexible as it can accommodate changing conditions over
   time (e.g., introduction of an additional VPN site).

   +------+                  +------+ +------+                  +------+
   |Client|                  |Server| |Client|                  |Server|
   +------+                  +------+ +------+                  +------+
      |=====Quotation Order=====>|       |=====Quotation Order=====>|
      |<==========Offer==========|       |<==========Offer==========|
      |===========Accept========>|       |==========Decline========>|

     1-Step Successful Negotiation         1-Step Failed Negotiation
               Cycle                               Cycle

   +------+                  +------+ +------+                  +------+
   |Client|                  |Server| |Client|                  |Server|
   +------+                  +------+ +------+                  +------+
      |===Quotation Order(a)====>|       |===Quotation Order(i)====>|
      |<==========Offer==========|       |<==========Offer==========|
      |==========Decline========>|       |==========Decline========>|
      |===Quotation Order(b)====>|       |===Quotation Order(j)====>|
      |<==========Offer==========|       |<==========Offer==========|
      |===========Accept========>|       |==========Decline========>|
                                         |===Quotation Order(k)====>|
                                         |<==========Offer==========|
                                         |==========Decline========>|
                                         |===Quotation Order(l)====>|
                                         |<==Fail to make an offer==|

       N-Step Negotiation Cycle:         N-Step Negotiation Cycle:
         Successful Negotiation              Failed Negotiation

                   Figure 3: Overall Negotiation Process




Boucadair, et al.      Expires September 15, 2016              [Page 12]


Internet-Draft                    CPNP                        March 2016


8.  Protocol Overview

8.1.  Client/Server Communication

   CPNP is a client/server protocol which is designed to run over any
   transport protocol with UDP being the default transport mode.  No
   permanent CPNP session needs to be maintained between the client and
   the server.  There is no need to run CPNP over a reliable transport
   mode because CPNP messages are acknowledged.

   The server uses CPNP_PORT (see Section 14) to bind the CPNP service.
   The client sends CPNP messages to CPNP_PORT.  The same port used as
   the source port of the request sent to the server must be used by the
   server to reply to that request.

   CPNP is independent of the IP address family.

   CPNP retransmission is discussed in Section 11.4.

8.2.  Server Discovery

   The CPNP client can be configured with the CPNP server(s) using
   manual or dynamic configuration means.  For example, Providers may
   configure dedicated SRV records ([RFC2782]) or may use a well-known
   name/address.

   Discussions about how the client can discovers its the server(s) of
   its interest are out of the scope of this document.  The document
   assumes that a the required CPNP server can be reached by the CPNP
   client, thanks to some configuration means.

8.3.  Policy Configuration on the CPNP Server

   As an input to its decision-making process, the CPNP server may be
   connected to various external modules such as: Customer Profiles,
   Network Topology, Network Resource Management, Orders Repository, AAA
   and Network Provisioning Manager (an example is shown in Figure 4).

   These external modules provide inputs to the CPNP server, so that it
   can:

   o  Check whether a customer is entitled to initiate a provisioning
      quotation request.

   o  Check whether a customer is entitled to cancel an on-going order.






Boucadair, et al.      Expires September 15, 2016              [Page 13]


Internet-Draft                    CPNP                        March 2016


   o  Check whether administrative data (e.g., billing-related
      information) have been verified before starting handling the
      request.

   o  Check whether network capacity is available or additional capacity
      is required.

   o  Receive guidelines from network design and sales blocks (e.g.,
      pricing, network usage levels, threshold on number of CPP
      templates that can be processed over a given period of time as a
      function of the nature of the service to be delivered, etc.).

   o  Transfer completed orders to network provisioning blocks.

   The above list of CPNP server operations is not exhaustive.

            . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
            .Business & Administrative Management                   .
            .+------------------------++---------------------------+.
            .| Business Guidelines    ||    Billing & Charging     |.
            .+-----------+------------++-----------+---------------+.
            .            |                         |                .
            .            +-------------------+     |                .
            . . . . . . . . . . . . . . . . .|. . .|. . . . . . . . .
            . . . . . . . . . . . . . . . . .|. . .|. . . . . . . . .
            .Order Handling Management       |     |                .
            . +-------------------+  +-------+-----+--------------+ .
            . |Network Topology DB+--+        CPNP Server         | .
            . +-------------------+  +-+---+---+---+---+-----+----+ .
            .                          |   |   |   |   |     |      .
            . +------------------------+-+ |   |   |   |     |      .
            . |   Network Dimensioning   | |   |   |   |     |      .
            . |        & Planning        | |   |   |   |     |      .
            . +--------------------------+ |   |   |   |     |      .
            . +----------------------------+-+ |   |   | +---+----+ .
            . |                              | |   |   | |   AAA  | .
            . |   Network       +------------+ |   |   | +--------+ .
            . |  Resource       | +------------+-+ | +-+----------+ .
            . |  Management     | |   Customer   | | |   Orders   | .
            . |                 | |   Profiles   | | | Repository | .
            . +-----------------+ +--------------+ | +------------+ .
            . . . . . . . . . . . . . . . . . . . .|. . . . . . . . .
            +--------------------------------------+----------------+
            |             Network Provisioning Manager              |
            +-------------------------------------------------------+

           Figure 4: Order Handling Management Functional Block




Boucadair, et al.      Expires September 15, 2016              [Page 14]


Internet-Draft                    CPNP                        March 2016


   The following order handling modes can be also configured on the
   server:

   1.  Fully automated mode: This mode does not require any action from
       the administrator when receiving a request for a service.  The
       server can execute its decision-making process related to the
       orders received and generate corresponding offers.
   2.  Administrative validation checking: Some or all of the server's
       operations are subject to administrative validation procedures.
       This mode requires an action from the administrator for every
       request received.  The CPNP methods which can be automatically
       handled by the server or they are subject to one or several
       validation administrative checks can be configured on the server.

8.4.  CPNP Session

   Both the client and server maintain the following CPNP transport
   session information:

   A CPNP session is identified by the following items:

   o  IP address of the client
   o  Client's port number
   o  IP address of the server
   o  Server's port number

8.5.  Extended CPNP Session

   An extended PQO session is denoted by a 5-uplet defined as follows:

   o  CPNP session (Section 8.4)

   o  Incremented Sequence Number (Section 11.3)

   o  Customer Agreement Identifier: This is a unique identifier
      assigned to the order under negotiation by the client
      (Section 9.1.1).  This identifier is also used to identify the
      agreement that will result from a successful negotiation.

   o  Provider Agreement Identifier: This is a unique identifier
      assigned to the order under negotiation by the server
      (Section 9.1.2).  This identifier is also used to identify the
      agreement that will result from a successful negotiation.

   o  Transaction-ID (Section 9.1.3)






Boucadair, et al.      Expires September 15, 2016              [Page 15]


Internet-Draft                    CPNP                        March 2016


8.6.  CPNP Transaction

   A CPNP transaction occurs between a client and a server for pursuing,
   modifying, withdrawing a service agreement and comprises all CPNP
   messages exchanged between the client and the server, from the first
   request sent by the client to the final response sent by the server.
   A CPNP transaction is bound to a CPNP session.

   Because multiple CPNP transactions can be maintained by the CPNP
   client, the client must assign an identifier to uniquely identify a
   given transaction.  This identifier is denoted as Transaction-ID.

   The Transaction-ID must be randomly assigned by the CPNP client,
   according to the best current practice for generating random numbers
   [RFC4086] that cannot be guessed easily.  Transaction-ID is used for
   validating CPNP responses received by the client.

   In the context of a transaction, the client needs to randomly select
   a sequence number and assign it in the first CPNP message to send.
   This number is then incremented for each request message is
   subsequently sent within the on-going CPNP transaction (see
   Section 11.3).

8.7.  CPNP Timers

   CPNP adopts a simple retransmission procedure which relies on a
   retransmission timer denoted as RETRANS_TIMER and maximum retry
   threshold.  The use of RETRANS_TIMER and a maximum retry threshold
   are described in Section 11.

   The response timer (RESPONSE_TIMER) is set by the client to denote
   the time, in seconds, the client will wait for receiving a response
   from the server to a provisioning quotation order request (see
   Section 9.1.6).  If the timer expires, the respective quotation order
   is cancelled by the client and a CANCEL message is generated
   accordingly.

   An offer expiration timer (EXPIRE_TIMER) is set by the server to
   represent the time, in minutes, after which an offer made by the
   server will be invalid (see Section 9.1.8).

8.8.  CPNP Operations

   The current CPNP operations are listed below.  They may be augmented,
   depending on the nature of some transactions or because of security
   considerations that may necessitate a distinct CPNP client/server
   authentication phase before negotiation begins.




Boucadair, et al.      Expires September 15, 2016              [Page 16]


Internet-Draft                    CPNP                        March 2016


   o  QUOTATION:

      This operation is used by the client to initiate a provisioning
      quotation order.  Upon receipt of a QUOTATION request, the server
      may respond with a PROCESSING, OFFER or a FAIL message.  A
      QUOTATION-initiated transaction can be terminated by a FAIL
      message.

   o  PROCESSING:

      This operation is used to inform the remote party that the message
      (the order quotation or the offer) sent was received and it is
      processed.  This message can also be issued by the server to
      request more time, in which case the client may reply with an ACK
      or FAIL message depending on whether more time can or cannot be
      granted.

   o  OFFER:

      This operation is used by the server to inform the client about an
      offer that can best accommodate the requirements indicated in the
      previously received QUOTATION message.

   o  ACCEPT:

      This operation is used by the client to confirm the acceptance of
      an offer made by the server.  This message implies a call for
      agreement.  An agreement is reached when an ACK is subsequently
      received from the server, which is likely to happen; it is rather
      unlikely the server to reject an offer that it has already made.

   o  ACK:

      This operation is used by the server to acknowledge the receipt of
      an ACCEPT or WITHDRAW message, or by the client to confirm the
      time extension requested by the server for processing the last
      received quotation order.

   o  DECLINE:

      This operation is used by the client to reject an offer made by
      the server.  The on-going transaction may not be terminated
      immediately, e.g., the server/client may issue another offer/
      order.

   o  CANCEL:





Boucadair, et al.      Expires September 15, 2016              [Page 17]


Internet-Draft                    CPNP                        March 2016


      This operation is used by the client to cancel (quit) the on-going
      transaction.

   o  WITHDRAW:

      This operation is used by the client to withdraw an agreement.

   o  UPDATE:

      This operation is used by the client to update an existing
      agreement.  For example, this method can be invoked to add a new
      site.  This method will trigger a new negotiation cycle.

   o  FAIL:

      This operation is used by the server to indicate that it cannot
      accommodate the requirements documented in the PQO conveyed in the
      QUOTATION message or to inform the client about an error
      encountered when processing the received message.  In either case,
      the message implies that the server is unable to make offers and
      as such it terminates the on-going transaction.

      This message is also used by the client to reject a time extension
      request received from the server (in a PROCESSING message).  The
      message includes a status code for providing explanatory
      information.

   Evidently, the above CPNP primitives are service-independent.  CPNP
   messages may transparently carry service-specific objects which are
   handled by the negotiation logic at either side.  The document
   specifies the service objects that are required for connectivity
   provisioning negotiation (see Section 8.9).  Additional service-
   specific objects to be carried in the CPNP messages can be defined in
   the future for accommodating alternative deployment or other service
   provisioning needs.

8.9.  Connectivity Provisioning Documents

   CPNP makes use of several flavors of Connectivity Provisioning
   Documents (CPD).  These documents follow the CPP template described
   in [RFC7297].

   o  Requested Connectivity Provisioning Document (Requested CPD):

      refers to the CPD included by a CPNP client in a QUOTATION
      request.

   o  Offered Connectivity Provisioning Document (Offered CPD):



Boucadair, et al.      Expires September 15, 2016              [Page 18]


Internet-Draft                    CPNP                        March 2016


      This document is included by a CPNP server in an OFFER message.
      Its information reflects the proposal of the server to accommodate
      all or a subset of the clauses depicted in a Requested CPD.  A
      validity time is associated with the offer made.

   o  Agreed Connectivity Provisioning Document (Agreed CPD):

      If the client accepts an offer made by the server, the Offered CPD
      is included in an ACCEPT message.  This CPD is also included in an
      ACK message.  Thus, a 3-way hand-shaking procedure is followed for
      successfully concluding the negotiation.

   Figure 5 shows a typical CPNP negotiation cycle and the use of the
   different types of Connectivity Provisioning Documents.

              +------+                              +------+
              |Client|                              |Server|
              +------+                              +------+
                 |======QUOTATION (Requested CPD)=====>|
                 |<============PROCESSING==============|
                 |<========OFFER (Offered CPD)=========|
                 |=============PROCESSING=============>|
                 |=========ACCEPT (Agreed CPD)========>|
                 |<=========ACK (Agreed CPD)===========|

               Figure 5: Connectivity Provisioning Documents

   A provisioning document can include parameters with fixed values,
   loosely defined values, or a combination thereof.  A provisioning
   document is said to be concrete if all clauses have fixed values.

   A typical evolution of a negotiation cycle would start with a
   quotation order with loosely defined parameters, and then, as offers
   are made, it would conclude with concrete provisioning document for
   calling for the agreement.

8.10.  Child Provisioning Quotation Orders

   If the server detects that network resources from another Network
   Provider need to be allocated in order to accommodate the
   requirements described in a PQO (e.g., in the context of an inter-
   domain VPN service, additional PE router resources need to be
   allocated), the server may generate child PQOs to request the
   appropriate network provisioning operations (see Figure 6).  In such
   situation, the server behaves also as a CPNP client.  The server
   associates the parent order with its child PQOs.  This is typically
   achieved by locally adding the reference of the child PQO to the
   parent order.



Boucadair, et al.      Expires September 15, 2016              [Page 19]


Internet-Draft                    CPNP                        March 2016


            +------+            +--------+          +--------+
            |Client|            |Server A|          |Server B|
            +------+            +--------+          +--------+
               |                    |                    |
               |=====QUOTATION=====>|                    |
               |<====PROCESSING=====|                    |
               |                    |=====QUOTATION=====>|
               |                    |<====PROCESSING=====|
               |                    |<=======OFFER=======|
               |                    |=====PROCESSING====>|
               |                    |=======ACCEPT======>|
               |                    |<=======ACK=========|
               |<=======OFFER=======|                    |
               |=====PROCESSING====>|                    |
               |=======ACCEPT======>|                    |
               |<=======ACK=========|                    |

                     Figure 6: Example of Child Orders

8.11.  Negotiations with Multiple CPNP Servers

   A CPNP client may undertake multiple negotiations in parallel with
   several servers for practical reasons such as cost optimization and
   fail-safety.  The multiple negotiations may lead to one or many
   agreements.  Multiple negotiations with the same Provider are not
   precluded.

   The salient point underlining the parallel negotiations scenario is
   that although the negotiation protocol is strictly between two
   parties, the negotiation logic may not necessarily be.  The CPNP
   client negotiation logic may need to collectively drive parallel
   negotiations, as the negotiation with one server may affect the
   negotiation with other servers; e.g., it may need to use the
   responses from all servers as input for determining the messages (and
   their content) to subsequently send in each individual negotiation.
   Timing is therefore an important aspect at the client's.  The CPNP
   client needs to have the ability to synchronize the receipt of the
   responses from the servers.  CPNP takes into account this requirement
   by allowing clients to specify in the QUOTATION message the time by
   which the server needs to respond (see Section 9.1.6).

8.12.  State Management

   Both the client and the server maintain repositories to store on-
   going orders.  How these repositories are maintained is deployment-
   specific.  It is out of scope of this document to elaborate on such
   considerations.  Timestamps are also logged to track state change.
   Tracking may be needed for various reasons,including regulatory ones.



Boucadair, et al.      Expires September 15, 2016              [Page 20]


Internet-Draft                    CPNP                        March 2016


8.12.1.  On the Client Side

   The following lists the states which can be associated with a given
   order on the client's side:

   o  Created: when the order has been created.  It is not handled by
      the client until the administrator allows to process it.

   o  AwaitingProcessing: when the administrator approved of processing
      a created order and the order has not been handled yet.

   o  PQOSent: when the order has been sent to the server.

   o  ServerProcessing: when the server has confirmed the receipt of the
      order.

   o  OfferReceived: when an offer has been received from the server.

   o  OfferProcessing: when a received offer is currently processed by
      the client.

   o  AcceptSent: when the client confirmed the offer to the server.

   o  AcceptAck: when the offer is acknowledged by the server.

   o  Cancelled: when the order has failed or cancelled.

























Boucadair, et al.      Expires September 15, 2016              [Page 21]


Internet-Draft                    CPNP                        March 2016


                 +------------------+
                 |     Created      |-----------------+
                 +------------------+                 |
                         |                            |
                         v                            |
                 +------------------+                 |
                 |AwaitingProcessing|----------------+|
                 +------------------+                ||
                         |                           ||
                      QUOTATION                      ||
                         v                           ||
                 +------------------+                ||
                 |     PQOSent      |---CANCEL------+||
                 +------------------+               vvv
                         |                        +-----+
                     PROCESSING                   |     |
                         v                        |     |
                 +------------------+   CANCEL    |  C  |
                 | ServerProcessing |------------>|  A  |
                 +------------------+    FAIL     |  N  |
                         |                        |  C  |
                         |                        |  E  |
                       OFFER                      |  L  |
                         |                        |  L  |
                         v                        |  E  |
                 +------------------+             |  D  |
                 |  OfferReceived   |---CANCEL--->|     |
                 +------------------+             |     |
                         | PROCESSING             +-----+
                         v                          ^^^
                 +------------------+               |||
                 |  OfferProcessing |---DECLINE-----+||
                 +------------------+                ||
                         | ACCEPT                    ||
                         v                           ||
                 +------------------+                ||
                 |    AcceptSent    |---CANCEL-------+|
                 +------------------+                 |
                         | ACK                        |
                         v                            |
                 +------------------+                 |
                 |   AcceptAck      |---WITHDRAW------+
                 +------------------+

             Figure 7: CPNP Finite State Machine (Client Side)






Boucadair, et al.      Expires September 15, 2016              [Page 22]


Internet-Draft                    CPNP                        March 2016


8.12.2.  On the Server Side

   The following lists the states which can be associated with a given
   order and a corresponding offer on the server's side:

   o  PQOReceived: when the order has been received from the client.

   o  AwaitingProcessing: when the order is being processed by the
      server.  An action from the server administrator may be needed.

   o  OfferProposed: when the request has been successfully handled and
      an offer has been sent to the client.

   o  ProcessingReceived: when the server received a PROCESSING for an
      offer sent to the client.

   o  AcceptReceived: when the server received a confirmation for the
      offer from the client.

   o  AcceptAck: when the server acknowledged the offer (accepted by
      client) to the client.

   o  Cancelled: when the order has failed to be met or it has been
      cancelled by the client.  Associate resources must be released in
      the latter case, if prior reserved.

   o  ChildCreated: when a child order has been created in cases where
      resources from another Network Provider are needed.

   o  ChildPQOSent: when a child order has been sent to the remote
      server.

   o  ChildServerProcessing: when a child order is currently processed
      by the remote server.

   o  ChildOfferReceived: when an offer has been received to a child
      order from the remote server.

   o  ChildOfferProcessing: when a received offer to a child order is
      currently processed.

   o  ChildAcceptSent: when the child offer (offer received from the
      remote server in response to a child order) is confirmed to the
      remote server.

   o  ChildAcceptAck: when an accepted child offer is acknowledged by
      the remote server.




Boucadair, et al.      Expires September 15, 2016              [Page 23]


Internet-Draft                    CPNP                        March 2016


                                 +------------------+
           +---------------------|    ChildCreated  |
           |                     +------------------+
           v                            |      ^
   +------------------+                 |      |
   |   ChildPQOSent   |----------------+|      Q
   +------------------+                ||      U
           |                           ||      O
        QUOTATION                      ||      T
           v                           ||      A  +--------------------+
   +---------------------+   CANCEL    ||      T  |     PQOReceived    |
   |ChildServerProcessing|------------+||      I  +--------------------+
   +---------------------+    FAIL    vvv      O       |      |
           |                        +-----+    N    CANCEL    |
       PROCESSING                   |     |<---|-------+  PROCESSING
           v                        |     |    |              v
   +------------------+             |     |   +------------------------+
   |ChildOfferReceived|----CANCEL---|  C  |<--|   AwaitingProcessing   |
   +------------------+             |  A  |   +------------------------+
           |                        |  N  |       ^          | OFFER
         OFFER                      |  C  |       | +------------------+
           |                        |  E  |<DECLINE-|   OfferProposed  |
           |                        |  L  |       | +------------------+
           v                        |  L  |       |          |
   +------------------+             |  E  |       |      PROCESSING
   |ChildOfferReceived|---CANCEL----|  D  |       |          v
   +------------------+             |     |       | +------------------+
           |                        |     |<DECLINE-| Proc'ingReceived |
      PROCESSING                    |     |         +------------------+
           |                        +-----+       |          | ACCEPT
           v                         ^^^^^        |          v
   +------------------+              |||||        | +------------------+
   |ChildOfferProc'ing|---DECLINE----+|||+-CANCEL-|-|  AcceptReceived  |
   +------------------+               |||         | +------------------+
           |ACCEPT                    |||         |          |ACK
           v                          |||         |          v
   +------------------+               |||         | +------------------+
   |  ChildAcceptSent |---CANCEL------+|+-WITHDRAW|-|    AcceptAck     |
   +------------------+                |          | +------------------+
           | ACK                       |          |
           v                           |          |
   +------------------+                |          |
   |  ChildAcceptAck  |---WITHDRAW-----+          |
   +------------------+                           |
           |                                      |
           +--------------------------------------+

             Figure 8: CPNP Finite State Machine (Server Side)



Boucadair, et al.      Expires September 15, 2016              [Page 24]


Internet-Draft                    CPNP                        March 2016


9.  CPNP Objects

   This section defines CPNP objects using the RBNF format defined at
   [RFC5511].

      Note: The formats of CPNP messages are provided using a generic
      format.  Implementors can adapt RBNF definitions to their
      "favorite" message format.

   This document focuses on connectivity provisioning objects;
   additional Information Elements (IEs) can be defined in the future.

9.1.  Attributes

9.1.1.  CUSTOMER_AGREEMENT_IDENTIFIER

   CUSTOMER_AGREEMENT_IDENTIFIER is an identifier which is assigned by a
   client to identify an agreement.  This identifier must be unique to
   the client.

   Rules for assigning this identifier are specific to the client
   (Customer).  The value of CUSTOMER_AGREEMENT_IDENTIFIER is included
   in all CPNP messages.

   The client (Customer) assigns an identifier to an order under
   negotiation before an agreement is reached.  This identifier will be
   used to unambiguously identify the resulting agreement at the client
   side (Customer).

   The server handles CUSTOMER_AGREEMENT_IDENTIFIER as an opaque value.

9.1.2.  PROVIDER_AGREEMENT_IDENTIFIER

   PROVIDER_AGREEMENT_IDENTIFIER is an identifier which is assigned by a
   server to identify an order.  This identifier must be unique to the
   server.

   Rules for assigning this identifier are specific to the server
   (Provider).  The value of PROVIDER_AGREEMENT_IDENTIFIER is included
   in all CPNP messages, except QUOTATION messages.

   The server (Provider) assigns an identifier to an order under
   negotiation before an agreement is reached.  This identifier will be
   used to unambiguously identify the resulting agreement at the server
   side (Provider).

   The client handles PROVIDER_AGREEMENT_IDENTIFIER as an opaque value.




Boucadair, et al.      Expires September 15, 2016              [Page 25]


Internet-Draft                    CPNP                        March 2016


9.1.3.  TRANSACTION_ID

   This object conveys the Transaction-ID introduced in Section 8.6.

9.1.4.  SEQUENCE_NUMBER

   Sequence Number is a number that is monotonically incremented on
   every new CPNP message within a CPNP transaction.  This number is
   used to avoid reply attacks.

   Refer to Section 11.3.

9.1.5.  NONCE

   NONCE is a random value assigned by the CPNP server.  It is
   RECOMMENDED to assign unique NONCE values for each order.

   NONCE is then mandatory to be included in subsequent CPNP client
   operations on the associated order (including the resulting
   agreement) such as: withdraw the order or update the order.

   If the NONCE validation checks fail, the server rejects the request
   with a FAIL message including the appropriate failure reason code.

9.1.6.  EXPECTED_RESPONSE_TIME

   This attribute indicates the time by when the CPNP client is
   expecting to receive a response, for a PQO, from the CPNP server.  If
   no offer is received by then, the CPNP client will consider the
   quotation order as rejected.

   EXPECTED_RESPONSE_TIME follows the date format specified in
   [RFC1123].

9.1.7.  EXPECTED_OFFER_TIME

   This attribute indicates the time by when the CPNP server is
   expecting to make an offer to the CPNP client.  If no offer is
   received by then, the CPNP client will consider the order as
   rejected.

   The CPNP server may propose an expected offer time that does not
   match the expected response time indicated in the quotation order
   message.  The CPNP client can accept or rejects the proposed expected
   time by when the CPNP server will make an offer.

   The CPNP server can always request extra time for its processing, but
   this may be accepted or rejected by the CPNP client.



Boucadair, et al.      Expires September 15, 2016              [Page 26]


Internet-Draft                    CPNP                        March 2016


   EXPECTED_OFFER_TIME follows the date format specified in [RFC1123].

9.1.8.  VALIDITY_OFFER_TIME

   This attribute indicates the time of validity of an offer made by the
   CPNP server.  If the offer is not accepted before this date expires,
   the CPNP server will consider the CPNP client has rejected the offer;
   the CPNP server will silently clear this order.

   VALIDITY_OFFER_TIME follows date format specified in [RFC1123].

9.1.9.  CONNECTIVITY_PROVISIONING_DOCUMENT

   The RBNF format of the Connectivity Provisioning Document (CPD) is
   shown in Figure 9:

   <CONNECTIVITY_PROVISIONING_DOCUMENT> ::=
                              <Connectivity Provisioning Component> ...
   <Connectivity Provisioning Component> ::=
                              <CONNECTIVITY_PROVISIONING_PROFILE> ...
   <CONNECTIVITY_PROVISIONING_PROFILE> ::=
                              <Customer Nodes Map>
                              <SCOPE>
                              <QoS Guarantees>
                              <Availability>
                              <CAPACITY>
                              <Traffic Isolation>
                              <Conformance Traffic>
                              <Flow Identification>
                              <Overall Traffic Guarantees>
                              <Routing and Forwarding>
                              <Activation Means>
                              <Invocation Means>
                              <Notifications>
   <Customer Nodes Map> ::=  <Customer Node> ...
   <Customer Node> ::=  <IDENTIFIER>
                        <LINK_IDENTIFIER>
                        <LOCALISATION>

    Figure 9: The RBNF format of the Connectivity Provisioning Document
                                   (CPD)

9.1.10.  Information Elements

   An Information Element (IE) is an optional object which can be
   included in a CPNP message.





Boucadair, et al.      Expires September 15, 2016              [Page 27]


Internet-Draft                    CPNP                        March 2016


9.1.10.1.  Customer Description

   The client may include administrative information such as:

   o  Name
   o  Contact Information

   The format of this Information Element is as follows:

   <Customer Description> ::= <NAME> <Contact Information>
   <Contact Information> ::=  <EMAIL_ADDRESS> [<POSTAL_ADDRESS>]
                              [<TELEPHONE_NUMBER> ...]

9.1.10.2.  Provider Description

   The server may include administrative information in an offer such
   as:

   o  Name
   o  AS Number ([RFC6793])
   o  Contact Information

   The format of this Information Element is as follows:

   <Provider Description> ::= <NAME><Contact Information>[<AS_NUMBER>]

9.1.10.3.  Negotiation Options

   The client may include some negotiation options such as:

   o  Cost: the client may include an empty or a preferred COST
      attribute to request the cost from the server.  The server will
      provide the cost information in the response.
   o  Setup purpose: A client may request to setup a connectivity only
      for testing purposes during a limited period.  The order can be
      extended to become permanent if the client was satisfied during
      the test period.  This operation is achieved using UPDATE method.

   Other negotiation options may be defined in the future.

   The format of this Information Element is as follows:

   <Negotiation Options> ::= [<COST>][<PURPOSE>]








Boucadair, et al.      Expires September 15, 2016              [Page 28]


Internet-Draft                    CPNP                        March 2016


9.2.  Operation Messages

   This section specifies the RBNF format of CPNP operation messages.

9.2.1.  QUOTATION

   The format of the QUOTATION message is shown below:

   <QUOTATION Message> ::=  <VERSION>
                          <METHOD_CODE>
                          <SEQUENCE_NUMBER>
                          <TRANSACTION_ID>
                          <CUSTOMER_AGREEMENT_IDENTIFIER>
                          [<EXPECTED_RESPONSE_TIME>]
                          <REQUESTED_CONNECTIVITY_PROVISIONING_DOCUMENT>
                          [<INFORMATION_ELEMENT>...]

   A QUOTATION message must include an order identifier which is
   generated by the client.  Because several orders can be issued to
   several servers, the QUOTATION message must also include a
   Transaction-ID.

   The message may include an EXPECTED_RESPONSE_TIME which indicates by
   when the client is expecting to receive an offer from the server.
   QUOTATION message must also include a requested connectivity
   provisioning document.

   When the client sends the QUOTATION message to the server, the state
   of the order changes to "PQOSent".

9.2.2.  PROCESSING

   The format of the PROCESSING message is shown below:

   <PROCESSING Message> ::= <VERSION>
                            <METHOD_CODE>
                            <SEQUENCE_NUMBER>
                            <TRANSACTION_ID>
                            <CUSTOMER_AGREEMENT_IDENTIFIER>
                            <PROVIDER_AGREEMENT_IDENTIFIER>
                            [<EXPECTED_OFFER_TIME>]

   Upon receipt of a QUOTATION message, the server proceeds with parsing
   rules (see Section 10).  If no error is encountered, the server
   generates a PROCESSING response to the client to indicate the PQO has
   been received and it is being processed.  The server must generate an
   order identifier which identifies the order in its local order
   repository.  The server MUST copy the content of



Boucadair, et al.      Expires September 15, 2016              [Page 29]


Internet-Draft                    CPNP                        March 2016


   CUSTOMER_AGREEMENT_IDENTIFIER and TRANSACTION_ID fields as conveyed
   in the QUOTATION message.  The server may include an
   EXPECTED_OFFER_TIME by when it expects to make an offer to the
   client.

   Upon receipt of a PROCESSING message, the client verifies whether it
   has issued a PQO to that server and which contains the
   CUSTOMER_AGREEMENT_IDENTIFIER and TRANSACTION_ID.  If no such PQO is
   found, the PROCESSING message is silently ignored.  If a PQO is
   found, the client may check if it accepts the EXPECTED_OFFER_TIME and
   then, it changes to state of the order to "ServerProcessing".

   If more time is required by the server to process the quotation
   order, it may send a PROCESSING message that includes a new
   EXPECTED_OFFER_TIME.  The client can answer with an ACK message if
   more time is granted (Figure 10) or with a FAIL message if the time
   extension is rejected (Figure 11).

              +------+                              +------+
              |Client|                              |Server|
              +------+                              +------+
                 |=======QUOTATION(Requested CPD)=====>|
                 |<========PROCESSING(time1)===========|
                                   ...
                 |<========PROCESSING(MoreTime)========|
                 |============ACK(TimeGranted)========>|
                                   ...
                 |<=========OFFER(Offered CPD)=========|
                 |=============PROCESSING=============>|
                 |==========ACCEPT(Agreed CPD)========>|
                 |<==========ACK(Agreed CPD)===========|

             Figure 10: Request more negotiation time: Granted

              +------+                              +------+
              |Client|                              |Server|
              +------+                              +------+
                 |=======QUOTATION(Requested CPD)=====>|
                 |<========PROCESSING(time1)===========|
                                   ...
                 |<========PROCESSING(MoreTime)========|
                 |===========FAIL(TimeRejected)=======>|

            Figure 11: Request more negotiation time: Rejected







Boucadair, et al.      Expires September 15, 2016              [Page 30]


Internet-Draft                    CPNP                        March 2016


9.2.3.  OFFER

   The format of the OFFER message is shown below:

   <OFFER Message> ::= <VERSION>
                       <METHOD_CODE>
                       <SEQUENCE_NUMBER>
                       <TRANSACTION_ID>
                       <CUSTOMER_AGREEMENT_IDENTIFIER>
                       <PROVIDER_AGREEMENT_IDENTIFIER>
                       <NONCE>
                       <VALIDITY_OFFER_TIME>
                       <OFFERED_CONNECTIVITY_PROVISIONING_DOCUMENT>
                       [<INFORMATION_ELEMENT>...]

   The server answers with an OFFER message to a QUOTATION request
   received from the client.  The offer will be considered as rejected
   by the client if no confirmation (ACCEPT message sent by the client)
   is received by the server before the expiration of the validity time.

9.2.4.  ACCEPT

   The format of the ACCEPT message is shown below:

   <ACCEPT Message> ::=  <VERSION>
                         <METHOD_CODE>
                         <SEQUENCE_NUMBER>
                         <TRANSACTION_ID>
                         <CUSTOMER_AGREEMENT_IDENTIFIER>
                         <PROVIDER_AGREEMENT_IDENTIFIER>
                         <NONCE>
                         <AGREED_CONNECTIVITY_PROVISIONING_DOCUMENT>
                         [<INFORMATION_ELEMENT>...]

   This message is used by a client to confirm the acceptance of an
   offer received from a server.  The fields of this message are copied
   from the received OFFER message.

9.2.5.  ACK

   The format of the ACK message is shown below:

   <ACK Message> ::=  <VERSION>
                    <METHOD_CODE>
                    <SEQUENCE_NUMBER>
                    <TRANSACTION_ID>
                    <CUSTOMER_AGREEMENT_IDENTIFIER>
                    <PROVIDER_AGREEMENT_IDENTIFIER>



Boucadair, et al.      Expires September 15, 2016              [Page 31]


Internet-Draft                    CPNP                        March 2016


                    [<EXPECTED_RESPONSE_TIME>]
                    [<CONNECTIVITY_PROVISIONING_DOCUMENT>]
                    [<INFORMATION_ELEMENT>...]

   This message is issued by the server to close a CPNP transaction or
   by a client to grant more negotiation time to the server.

   This message is sent by the server as a response to an ACCEPT,
   WITHDRAW, DECLINE, or CANCEL message.  In such case, the ACK message
   must include the copy of the Connectivity Provisioning Document as
   stored by the server, in particular:

   o  A copy of the requested/offered CPD is included by the server if
      it successfully handled a CANCEL message.
   o  A copy of the updated CPD is included by the server if it
      successfully handled an UPDATE message.
   o  A copy of the offered CPD is included by the server if it
      successfully handled an ACCEPT message in the context of a
      QUOTATION transaction.
   o  An empty CPD is included by the server if it successfully handled
      a DECLINE message.

   A client may issue an ACK message as a response to a more time
   request (conveyed in PROCESSING) received from the server.  In such
   case, the ACK message must include an EXPECTED_RESPONSE_TIME that is
   likely to be set to the time extension requested by the server.

9.2.6.  DECLINE

   The format of the DECLINE message is shown below:

   <DECLINE Message> ::=  <VERSION>
                        <METHOD_CODE>
                        <SEQUENCE_NUMBER>
                        <TRANSACTION_ID>
                        <CUSTOMER_AGREEMENT_IDENTIFIER>
                        <PROVIDER_AGREEMENT_IDENTIFIER>
                        <NONCE>

   The client can issue a DECLINE message to reject an offer.
   CUSTOMER_AGREEMENT_IDENTIFIER, PROVIDER_AGREEMENT_IDENTIFIER,
   TRANSACTION_ID, and NONCE are used by the server as keys to find the
   corresponding order.  If an order matches, the server changes the
   state of this order to "Cancelled" and then returns an ACK with a
   copy of the requested CPD to the requesting client.

   If no order is found, the server returns a FAIL message to the
   requesting client.



Boucadair, et al.      Expires September 15, 2016              [Page 32]


Internet-Draft                    CPNP                        March 2016


   A flow example is shown in Figure 12.

              +------+                              +------+
              |Client|                              |Server|
              +------+                              +------+
                 |=======QUOTATION(Requested CPD)=====>|
                 |<============PROCESSING==============|
                 |<=========OFFER(Offered CPD)=========|
                 |=============PROCESSING=============>|
                 |===============DECLINE==============>|
                 |<================ACK=================|

                      Figure 12: DECLINE Flow Example

9.2.7.  CANCEL

   The format of the CANCEL message is shown below:

   <CANCEL Message> ::= <VERSION>
                        <METHOD_CODE>
                        <SEQUENCE_NUMBER>
                        <TRANSACTION_ID>
                        <CUSTOMER_AGREEMENT_IDENTIFIER>
                        [<CONNECTIVITY_PROVISIONING_DOCUMENT>]

   The client can issue a CANCEL message at any stage during the CPNP
   negotiation process before an agreement is reached.
   CUSTOMER_AGREEMENT_IDENTIFIER and TRANSACTION_ID are used by the
   server as keys to find the corresponding order.  If a quotation order
   matches, the server changes the state of this quotation order to
   "Cancelled" and then returns an ACK with a copy of the requested CPD
   to the requesting client.

   If no quotation order is found, the server returns a FAIL message to
   the requesting client.

9.2.8.  WITHDRAW

   The format of the WITHDRAW message is shown below:

   <WITHDRAW Message> ::= <VERSION>
                          <METHOD_CODE>
                          <SEQUENCE_NUMBER>
                          <TRANSACTION_ID>
                          <CUSTOMER_AGREEMENT_IDENTIFIER>
                          <PROVIDER_AGREEMENT_IDENTIFIER>
                          <NONCE>
                          [<AGREED_CONNECTIVITY_PROVISIONING_DOCUMENT>]



Boucadair, et al.      Expires September 15, 2016              [Page 33]


Internet-Draft                    CPNP                        March 2016


                          [<INFORMATION_ELEMENT>...]

   This message is used to withdraw an offer already subscribed by the
   Customer.  Figure 13 shows a typical usage of this message.

              +------+                              +------+
              |Client|                              |Server|
              +------+                              +------+
                 |============WITHDRAW(CPD)===========>|
                 |<============PROCESSING==============|
                 |<===========ACK(Empty CPD)===========|

                     Figure 13: WITHDRAW Flow Example

   The CPNP must include the same CUSTOMER_AGREEMENT_IDENTIFIER,
   PROVIDER_AGREEMENT_IDENTIFIER, and NONCE as those used when creating
   the order.

   Upon receipt of a WITHDRAW message, the server checks whether an
   order matching the request is found.  If an order is found, the state
   of the order is changed to "Cancelled" and an ACK message including
   an Empty CPD is returned to the requesting client.  If no order is
   found, the server returns a FAIL message to the requesting client.

9.2.9.  UPDATE

   The format of the UPDATE message is shown below:

   <UPDATE Message> ::= <VERSION>
                        <METHOD_CODE>
                        <SEQUENCE_NUMBER>
                        <TRANSACTION_ID>
                        <CUSTOMER_AGREEMENT_IDENTIFIER>
                        <PROVIDER_AGREEMENT_IDENTIFIER>
                        <NONCE>
                        <EXPECTED_RESPONSE_TIME>
                        <REQUESTED_CONNECTIVITY_PROVISIONING_DOCUMENT>
                        [<INFORMATION_ELEMENT>...]

   This message is sent by the CPNP client to update an existing
   connectivity provisioning agreement.  The CPNP must include the same
   CUSTOMER_AGREEMENT_IDENTIFIER, PROVIDER_AGREEMENT_IDENTIFIER, and
   NONCE as those used when creating the order.  The CPNP client
   includes a new CPD which integrates the requested modifications.  A
   new Transaction_ID must be assigned by the client.

   Upon receipt of an UPDATE message, the server checks whether an
   order, having state "Completed", matches



Boucadair, et al.      Expires September 15, 2016              [Page 34]


Internet-Draft                    CPNP                        March 2016


   CUSTOMER_AGREEMENT_IDENTIFIER, PROVIDER_AGREEMENT_IDENTIFIER, and
   NONCE.

   o  If no order is found, the CPNP server generates a FAIL error with
      the appropriate error code.
   o  If an order is found, the server checks whether it can honor the
      request:

      *  A FAIL message is sent to the client if the server cannot honor
         the request.  The client may initiate a new PQO negotiation
         cycle.
      *  An OFFER message including the updated connectivity
         provisioning document is sent to the client.  For example, the
         server maintains an order for provisioning a VPN service that
         connects sites A, B and C.  If the client sends an UPDATE
         message to remove site C, only sites A and B will be included
         in the OFFER sent by the server to the requesting client.

   A flow chart that illustrates the use of UPDATE operation is shown in
   Figure 14.

              +------+                              +------+
              |Client|                              |Server|
              +------+                              +------+
                 |=========UPDATE(Requested CPD)======>|
                 |<============PROCESSING==============|
                 |<=========OFFER(Updated CPD)=========|
                 |=============PROCESSING=============>|
                 |==========ACCEPT(Updated CPD)=======>|
                 |<==========ACK(Updated CPD)==========|

                      Figure 14: UPDATE Flow Example

9.2.10.  FAIL

   The format of the FAIL message is shown below:

   <FAIL Message> ::= <VERSION>
                      <METHOD_CODE>
                      <SEQUENCE_NUMBER>
                      <TRANSACTION_ID>
                      <CUSTOMER_AGREEMENT_IDENTIFIER>
                      <PROVIDER_AGREEMENT_IDENTIFIER>
                      <STATUS_CODE>

   This message is sent in the following cases:





Boucadair, et al.      Expires September 15, 2016              [Page 35]


Internet-Draft                    CPNP                        March 2016


   o  The server can not honor an order received from the client (i.e.,
      received in a QUOTATION or UPDATE request).
   o  The server encounters an error when processing a CPNP request
      received from the client.
   o  The client can not grant more time to a the server.  This is a
      response to a more time request conveyed in a PROCESSING message.

   The status code indicates the error code.  The following codes are
   currently supported; other codes will be defined in future versions
   of the document:

   1  (Validation Error): The message can not be validated (see
      Section 10).
   2  (Authentication Required): the request cannot be handled because
      authentication is required.
   3  (Authorization Required): the request cannot be handled because
      authorization failed.
   4  (Administratively prohibited): the request can not be handled
      because of administrative policies.
   5  (Out of Resources): the request can not be honored because there
      is not enough capacity.
   6  (Network Presence): the request can not be honored because there
      is no network presence.
   7  (More Time Rejected): the request to extend the time negotiation
      is rejected by the client.

10.  Message Validation

   Both client and server proceed with CPNP message validation.  The
   following tables summarize the validation checks to be followed.

10.1.  On the Client Side



















Boucadair, et al.      Expires September 15, 2016              [Page 36]


Internet-Draft                    CPNP                        March 2016


   Operation    Validation Checks
   ------------ --------------------------------------------------------
   PROCESSING   {Source IP address, source port, destination IP address,
                destination port, Transaction-ID, Customer Order
                Identifier} must match an existing PQO with a state set
                to "PQOSent". The sequence number carried in the packet
                must be larger than the sequence number maintained by
                the client.
   OFFER        {Source IP address, source port, destination IP address,
                destination port, Transaction-ID, Customer Order
                Identifier} must match an existing order with state set
                to "PQOSent" or {Source IP address, source port,
                destination IP address, destination port, Transaction-
                ID, Customer Order Identifier, Provider Order
                Identifier} must match an existing order with a state
                set to "ServerProcessing". The sequence number carried
                in the packet must be larger than the sequence number
                maintained by the client.
   ACK          {Source IP address, source port, destination IP address,
   (QUOTATION   destination port, Transaction-ID, Customer Order
   Transaction) Identifier, Provider Order Identifier, Offered
                Connectivity Provisioning Order} must match an order
                with a state set to "AcceptSent". The sequence number
                carried in the packet must be larger than the sequence
                number maintained by the client.
   ACK (UPDATE  {Source IP address, source port, destination IP address,
   Transaction) destination port, Transaction-ID, Customer Order
                Identifier, Provider Order Identifier, Updated
                Connectivity Provisioning Order} must match an order
                with a state set to "AcceptSent". The sequence number
                carried in the packet must be larger than the sequence
                number maintained by the client.
   ACK          {Source IP address, source port, destination IP address,
   (WITHDRAW    destination port, Transaction-ID, Customer Order
   Transaction) Identifier, Provider Order Identifier, Empty
                Connectivity Provisioning Order} must match an order
                with a state set to "Cancelled". The sequence number
                carried in the packet must be larger than the sequence
                number maintained by the client.

10.2.  On the Server Side










Boucadair, et al.      Expires September 15, 2016              [Page 37]


Internet-Draft                    CPNP                        March 2016


   Method     Validation Checks
   ---------- ----------------------------------------------------------
   QUOTATION  The source IP address passes existing access filters (if
              any).  The sequence number carried in the packet must not
              be less than the sequence number maintained by the server.
   PROCESSING The sequence number carried in the packet must be larger
              than the sequence number maintained by the server.
   ACCEPT     {Source IP address, source port, destination IP address,
              destination port, Transaction-ID, Customer Order
              Identifier, Provider Order Identifier, Nonce, Offered
              Connectivity Provisioning Order} must match an order with
              state set to "OfferProposed" or "ProcessngReceived". The
              sequence number carried in the packet must be larger than
              the sequence number maintained by the server.
   DECLINE    {Source IP address, source port, destination IP address,
              destination port, Transaction-ID, Customer Order
              Identifier, Provider Order Identifier, Nonce} must match
              an order with state set to "OfferProposed" or
              "ProcessngReceived". The sequence number carried in the
              packet must be larger than the sequence number maintained
              by the server.
   UPDATE     The source IP address passes existing access filters (if
              any) and {Customer Order Identifier, Provider Order
              Identifier, Nonce} must match an existing order with state
              "Completed".
   WITHDRAW   The source IP address passes existing access filters (if
              any) and {Customer Order Identifier, Provider Order
              Identifier, Nonce} must match an existing order with state
              "Completed".

11.  Theory of Operation

   Both CPNP client and server proceeds to message validation checks as
   specified in Section 10.

11.1.  Client Behavior

11.1.1.  Order Negotiation Cycle

   To place a provisioning quotation order, the client initiates first a
   local quotation order object identified by a unique identifier
   assigned by the client.  The state of the quotation order is set to
   "Created".  The client then generates a QUOTATION request which
   includes the assigned identifier, possibly an expected response time,
   a Transaction-ID and a Requested Connectivity Provisioning Document.
   The client may include additional Information Elements such as
   Negotiation Options.




Boucadair, et al.      Expires September 15, 2016              [Page 38]


Internet-Draft                    CPNP                        March 2016


   The client may be configured to not enforce negotiation checks on
   EXPECTED_OFFER_TIME; if so no EXPECTED_RESPONSE_TIME attribute (or
   EXPECTED_RESPONSE_TIME set to infinite) should be included in the
   quotation order.

   Once the request is sent to the server, the state of the request is
   set to "PQOSent" and a timer, if a response time is included in the
   quotation order, is set to the expiration time as included in the
   QUOTATION request.  The client also maintains a copy of the extended
   transport session details used to generate the QUOTATION request.
   The CPNP client must listen on the same port number that it used to
   send the QUOTATION request.

   If no answer is received from the server before the retransmission
   timer expires (i.e., RETRANS_TIMER, Section 8.7), the client proceeds
   to retransmission until maximum retry is reached (i.e., 3 times).
   The same sequence number is used for retransmitted packets.

   If a FAIL message is received, the client may decide to issue another
   (corrected) request towards the same server, cancel the local order,
   or contact another server.  The behavior of the client depends on the
   error code returned by the server in the FAIL message.

   If a PROCESSING message matching the CPNP transport session is
   received, the client updates the CPNP session with the
   PROVIDER_AGREEMENT_IDENTIFIER information.  If the client does not
   accept the expected offer time that may have been indicated in the
   PROCESSING message, the client may decide to cancel the quotation
   order.  If the client accepts the EXPECTED_OFFER_TIME, it changes the
   state of the order to "ServerProcessing" and sets a timer to the
   value of EXPECTED_OFFER_TIME.  If no offer is made before the timer
   expires, the client changes the state of the order to "Cancelled".

   As a response to a more time request (conveyed in a PROCESSING
   message that included a new EXPECTED_OFFER_TIME), the client may
   grant this extension by issuing an ACK message or reject the time
   extension with a FAIL message having a status code set to "More Time
   Rejected".

   If an OFFER message matching the extended CPNP session is received,
   the client checks if a PROCESSING message having the same
   PROVIDER_AGREEMENT_IDENTIFIER has been received from the server.  If
   a PROCESSING message was already received for the same order but the
   PROVIDER_AGREEMENT_IDENTIFIER does not match the identifier included
   in the OFFER message, the client ignores silently the message.  If a
   PROCESSING message having the same PROVIDER_AGREEMENT_IDENTIFIER was
   already received and matches the CPNP transaction identifier, the
   client changes the state of the order to "OfferReceived" and sets a



Boucadair, et al.      Expires September 15, 2016              [Page 39]


Internet-Draft                    CPNP                        March 2016


   timer to the value of VALIDITY_OFFER_TIME indicated in the OFFER
   message.

   If an offer is received from the server (i.e., as documented in an
   OFFER message), the client may accept or reject the offer.  The
   client accepts the offer by generating an ACCEPT message which
   confirms that the client agrees to subscribe to the offer documented
   in the OFFER message; the state of the order is passed to
   "AcceptSent".  The transaction is terminated if an ACK message is
   received from the server.  If no ACK is received from the server, the
   client proceeds with the re-transmission of the ACCEPT message.

   The client may also decide to reject the offer by sending a DECLINE
   message.  The state of the order is set by the client to "Cancelled".
   If an offer is not acceptable by the client, the client may decide to
   contact a new server or submit another order to the same server.
   Guidelines to issue an updated order or terminate the negotiation are
   specific to the client.

11.1.2.  Order Withdrawal Cycle

   A client may withdraw a completed order.  This is achieved by issuing
   a WITHDRAW message.  This message must include Customer Order
   Identifier, Provider Identifier and Nonce returned during the order
   negotiation cycle specified in Section 11.1.1.

   If no ACK is received from the server, the client proceeds with the
   re-transmission of the message.

11.1.3.  Order Update Cycle

   A client may update a completed order.  This is achieved by issuing
   an UPDATE message.  This message must include Customer Order
   Identifier, Provider Order Identifier and Nonce returned during the
   order negotiation cycle specified in Section 11.1.1.  The client must
   include in the UPDATE message an updated CPD with the requested
   changes.

   Subsequent messages exchange is similar to what is documented in
   Section 11.1.1.

11.2.  Server Behavior

11.2.1.  Order Processing

   Upon receipt of a QUOTATION message from a client, the server sets a
   CPNP session, stores Transaction-ID and generates a Provider Order
   Identifier.  Once preliminary validation checks are completed (



Boucadair, et al.      Expires September 15, 2016              [Page 40]


Internet-Draft                    CPNP                        March 2016


   Section 10), the server may return a PROCESSING message to notify the
   client the quotation order is received and it is under processing;
   the server may include an expected offer time to notify the client by
   when an offer will be proposed.  An order with state
   "AwaitingProcessing" is created by the server.  The server runs its
   decision-making process to decide which offer it can make to honor
   the received order.  The offer should be made before the expected
   offer time expires.

   If the server cannot make an offer, it sends backs a FAIL message
   with the appropriate error code.

   If the server requires more negotiation time, it must send a
   PROCESSING message with a new EXPECTED_OFFER_TIME.  The client may
   grant this extension by issuing an ACK message or reject the time
   extension with a FAIL message having a status code set to "More Time
   Rejected".  If the client doesn't grant more time, the server must
   answer before the initial expected offer time; otherwise the client
   will ignore the quotation order.

   If the server can honor the request or it can make an offer that meet
   some of the requirements, it creates an OFFER message.  The server
   must indicate the Transaction-ID, Customer Order Identifier as
   indicated in the QUOTATION message, and the Provider Order Identifier
   generated for this order.  The server must also include Nonce and the
   offered Connectivity Provisioning Document.  The server includes an
   offer validity time as well.  Once sent to the client, the server
   changes the state of the order to "OfferSent" and a timer set to the
   validity time is initiated.

   If the server determines that additional network resources from
   another network provider are needed to accommodate a quotation order,
   it will create child PQO(s) and will behave as a CPNP client to
   negotiate child PQO(s) with possible partnering providers (see
   Figure 6).

   If no PROCESSING, ACCEPT or DECLINE message is received before the
   expiry of the RETRANS_TIMER, the server re-sends the same offer to
   the client.  This procedure is repeated until maximum retry is
   reached.

   If an ACCEPT message is received before the offered validity time
   expires, the server proceeds with validation checks as specified in
   Section 10.  The state of the corresponding order is passed to
   "AcceptReceived".  The server sends back an ACK message to terminate
   the order processing cycle.





Boucadair, et al.      Expires September 15, 2016              [Page 41]


Internet-Draft                    CPNP                        March 2016


   If a CANCEL/DECLINE message is received, the server proceeds with the
   cancellation of the order.  The state of the order is then passed to
   "Cancelled".

11.2.2.  Order Withdrawal

   A client may withdraw a completed order by issuing a WITHDRAW
   message.  Upon receipt of a WITHDRAW message, the server proceeds
   with the validation checks, as specified in Section 10.

   o  If the checks fail, a FAIL message is sent back to the client with
      the appropriate error code.

   o  If the checks succeed, the server clears the clauses of the
      Connectivity Provisioning Document, changes the state of the order
      to "Cancelled", and sends back an ACK message with an Empty
      Connectivity Provisioning Document.

11.2.3.  Order Update

   A client may update an order by issuing an UPDATE message.  Upon
   receipt of an UPDATE message, the server proceeds with the validation
   checks as specified in Section 10.

   o  If the checks fail, a FAIL message is sent back to the client with
      the appropriate error code.
   o  Subsequent messages exchange is similar to what is specified in
      Section 11.1.1.  The server should generate a new Nonce value to
      be included in the offer made to the client.

11.3.  Sequence Numbers

   In each transaction, sequence numbers are used to protect the
   transaction against replay attacks.  Each communicating partner of
   the transaction maintains two sequence numbers, one for incoming
   packets and one for outgoing packets.  When a partner receives a
   message, it will check whether the sequence number in the message is
   larger than the incoming sequence number maintained locally.  If not,
   the messages will be discarded.  If the message is proved to be
   legal, the value of the incoming sequence number will be replaced by
   the value of the sequence number in the message.  When a partner
   sends out a message, it will insert the value of outgoing sequence
   number into the message and increase the outgoing sequence number
   maintained locally by 1.







Boucadair, et al.      Expires September 15, 2016              [Page 42]


Internet-Draft                    CPNP                        March 2016


11.4.  Message Re-Transmission

   If a transaction partner sends out a message and does not receive any
   expected reply before the retransmission timer expires (i.e.,
   RETRANS_TIMER), a transaction partner will try to re-transit the
   messages.  An exception is the last message (e.g., ACK) sent from the
   server in a transaction.  After sending this message, the
   retransmission timer will be disabled since no additional feedback is
   expected.

   In addition, if the partner receives a re-sent last incoming packet,
   the partner can also send out the answer to the incoming packet with
   a limited frequency.  If no answer was generated at the moment, the
   partner needs to generate a PROCESSING message as the answer.

   To benefit message re-transmission, a partner could also store the
   last incoming packet and the associated answer.  Note that the times
   of re-transmission could be decided by the local policy and re-
   transmission will not cause any change of sequence numbers.

12.  Operational Guidelines

12.1.  Logging on the CPNP Server

   The CPNP server SHOULD be configurable to log various events and
   associated information.  Such information includes:

   o  Client's IP address
   o  Any event change (e.g., new quotation order, offer sent, order
      confirm, order cancellation, order withdraw, etc.)
   o  Timestamp

12.2.  Business Guidelines & Objectives

   The CPNP server can operate in the following modes:

   1.  Fully automated mode: The CPNP server is provisioned with a set
       of business guidelines and objectives that will be used as an
       input to the decision-making process.  The CPNP server will
       service received orders that falls into these business
       guidelines; otherwise requests will be escalated to an
       administrator that will formally validate/invalidate an order
       request.  The set of policies to be configured to the CPNP server
       are specific to each administrative entity managing a CPNP
       server.

   2.  Administrative-based mode: This mode assumes some or all CPNP
       server' operations are subject to a formal administrative



Boucadair, et al.      Expires September 15, 2016              [Page 43]


Internet-Draft                    CPNP                        March 2016


       validation.  CPNP events will trigger appropriate validation
       requests that will be forwarded to the contact person(s) or
       department which is responsible for validating the orders.
       Administrative validation messages are relayed using another
       protocol (e.g., SMTP) or a dedicated tool.

   Business guidelines are local to each administrative entity.  How
   validation requests are presented to an administrator are out of
   scope of this document; each administrative entity may decide the
   appropriate mechanism to enable for that purpose.

13.  Security Considerations

   Means to defend the server against denial-of-service attacks must be
   enabled.  For example, access control lists (ACLs) can be enforced on
   the client, the server or the network in between, to allow a trusted
   client to communicate with a trusted server.

   The client and the server should be mutually authenticated.  Out of
   band mechanisms can be used instead of integrating them into CPNP.

   The client must silently discard CPNP responses received from unknown
   CPNP servers.  The use of a randomly generated Transaction-ID makes
   it hard to forge a response from a server with a spoofed IP address
   belonging to a legitimate CPNP server.  Furthermore, CPNP demands
   that messages from the server must include correct identifiers of the
   orders.  Two order identifiers are used: one generated by the client
   and a second one generated by the server.

   The Provider must enforce means to protect privacy-related
   information included the documents (see Section 8.9) exchanged using
   CPNP messages [RFC6462].  In particular, this information must not be
   revealed to external parties without the consent of Customers.
   Providers should enforce policies to make Customer fingerprinting
   difficult to achieve.  For more discussion about privacy, refer to
   [RFC6462][RFC6973].

   The NONCE and the Transaction ID attributes provide sufficient
   randomness and can effectively tolerate attacks raised by off-line
   adversaries, who do not have the capability of eavesdropping and
   intercepting the packets transported between the client and the
   server.  Only authorized clients must be able to modify agreed CPNP
   orders.  The use of a randomly generated NONCE by the server makes it
   hard to modify an agreement on behalf of a malicious third-party.

   The sequence numbers included in the CPNP messages can be used to
   detect replay attacks and antique packets intercepted from on-going
   transactions may be re-sent.  However, the protocol in its current



Boucadair, et al.      Expires September 15, 2016              [Page 44]


Internet-Draft                    CPNP                        March 2016


   version may be vulnerable to replay attacks where the replayed
   messages are intercepted from antique transactions.  Although the
   Transaction ID provided by the client could protect inter-transaction
   replay attacks, no protection is provided for the server to deal with
   this type of attack.

   The protocol does not provide security mechanisms to protect the
   confidentiality and integrity of the packets transported between the
   client and the server.  An underlying security protocol such as
   (e.g., DTLS [RFC6347], IPsec) could be used to protect the integrity
   and confidentiality for the protocol.  In this case, if it is
   possible to provide an Automated Key Management (AKM) and associate
   each transaction with a different key, inter- transaction replay
   attacks can naturally be addressed.  If the client and the server use
   a single key, an additional mechanism should be provided to protect
   inter-transaction replay attacks between them.

   The deployment option of a Customer Order Management portal operated
   by a trusted third-party (see Section 6) may facilitate the efficient
   resolution of the aforementioned security concerns.

14.  IANA Considerations

   Authors of the document request IANA to assign a UDP port for CPNP.

   A registry for CPNP methods should be created.  The following initial
   codes should be reserved:

   1:   QUOTATION
   2:   PROCESSING
   3:   OFFER
   4:   ACCEPT
   5:   DECLINE
   6:   ACK
   7:   CANCEL
   8:   WITHDRAW
   9:   UPDATE
   10:  FAIL

   A registry for CPNP error codes should be created.  The following
   initial error codes should be reserved:

   1:  Message Validation Error
   2:  Authentication Required
   3:  Authorization Failed
   4:  Administratively prohibited
   5:  Out of Resources
   6:  Network Presence Error



Boucadair, et al.      Expires September 15, 2016              [Page 45]


Internet-Draft                    CPNP                        March 2016


   7:  More Time Rejected

15.  Acknowledgements

   Thanks to Diego R.  Lopez for his comments.

16.  References

16.1.  Normative References

   [RFC1123]  Braden, R., Ed., "Requirements for Internet Hosts -
              Application and Support", STD 3, RFC 1123,
              DOI 10.17487/RFC1123, October 1989,
              <http://www.rfc-editor.org/info/rfc1123>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <http://www.rfc-editor.org/info/rfc2119>.

   [RFC4086]  Eastlake 3rd, D., Schiller, J., and S. Crocker,
              "Randomness Requirements for Security", BCP 106, RFC 4086,
              DOI 10.17487/RFC4086, June 2005,
              <http://www.rfc-editor.org/info/rfc4086>.

   [RFC5511]  Farrel, A., "Routing Backus-Naur Form (RBNF): A Syntax
              Used to Form Encoding Rules in Various Routing Protocol
              Specifications", RFC 5511, DOI 10.17487/RFC5511, April
              2009, <http://www.rfc-editor.org/info/rfc5511>.

16.2.  Informative References

   [ETICS]    EU FP7 ETICS Project, "Economics and Technologies of
              Inter-Carrier Services", January 2014, <https://www.ict-
              etics.eu/fileadmin/documents/news/
              ETICS_white_paper_final.pdf>.

   [I-D.boucadair-lisp-idr-ms-discovery]
              Boucadair, M. and C. Jacquenet, "LISP Mapping Service
              Discovery at Large", draft-boucadair-lisp-idr-ms-
              discovery-01 (work in progress), March 2016.

   [RFC2782]  Gulbrandsen, A., Vixie, P., and L. Esibov, "A DNS RR for
              specifying the location of services (DNS SRV)", RFC 2782,
              DOI 10.17487/RFC2782, February 2000,
              <http://www.rfc-editor.org/info/rfc2782>.





Boucadair, et al.      Expires September 15, 2016              [Page 46]


Internet-Draft                    CPNP                        March 2016


   [RFC4026]  Andersson, L. and T. Madsen, "Provider Provisioned Virtual
              Private Network (VPN) Terminology", RFC 4026,
              DOI 10.17487/RFC4026, March 2005,
              <http://www.rfc-editor.org/info/rfc4026>.

   [RFC4176]  El Mghazli, Y., Ed., Nadeau, T., Boucadair, M., Chan, K.,
              and A. Gonguet, "Framework for Layer 3 Virtual Private
              Networks (L3VPN) Operations and Management", RFC 4176,
              DOI 10.17487/RFC4176, October 2005,
              <http://www.rfc-editor.org/info/rfc4176>.

   [RFC6347]  Rescorla, E. and N. Modadugu, "Datagram Transport Layer
              Security Version 1.2", RFC 6347, DOI 10.17487/RFC6347,
              January 2012, <http://www.rfc-editor.org/info/rfc6347>.

   [RFC6462]  Cooper, A., "Report from the Internet Privacy Workshop",
              RFC 6462, DOI 10.17487/RFC6462, January 2012,
              <http://www.rfc-editor.org/info/rfc6462>.

   [RFC6574]  Tschofenig, H. and J. Arkko, "Report from the Smart Object
              Workshop", RFC 6574, DOI 10.17487/RFC6574, April 2012,
              <http://www.rfc-editor.org/info/rfc6574>.

   [RFC6770]  Bertrand, G., Ed., Stephan, E., Burbridge, T., Eardley,
              P., Ma, K., and G. Watson, "Use Cases for Content Delivery
              Network Interconnection", RFC 6770, DOI 10.17487/RFC6770,
              November 2012, <http://www.rfc-editor.org/info/rfc6770>.

   [RFC6793]  Vohra, Q. and E. Chen, "BGP Support for Four-Octet
              Autonomous System (AS) Number Space", RFC 6793,
              DOI 10.17487/RFC6793, December 2012,
              <http://www.rfc-editor.org/info/rfc6793>.

   [RFC6830]  Farinacci, D., Fuller, V., Meyer, D., and D. Lewis, "The
              Locator/ID Separation Protocol (LISP)", RFC 6830,
              DOI 10.17487/RFC6830, January 2013,
              <http://www.rfc-editor.org/info/rfc6830>.

   [RFC6973]  Cooper, A., Tschofenig, H., Aboba, B., Peterson, J.,
              Morris, J., Hansen, M., and R. Smith, "Privacy
              Considerations for Internet Protocols", RFC 6973,
              DOI 10.17487/RFC6973, July 2013,
              <http://www.rfc-editor.org/info/rfc6973>.

   [RFC7149]  Boucadair, M. and C. Jacquenet, "Software-Defined
              Networking: A Perspective from within a Service Provider
              Environment", RFC 7149, DOI 10.17487/RFC7149, March 2014,
              <http://www.rfc-editor.org/info/rfc7149>.



Boucadair, et al.      Expires September 15, 2016              [Page 47]


Internet-Draft                    CPNP                        March 2016


   [RFC7297]  Boucadair, M., Jacquenet, C., and N. Wang, "IP
              Connectivity Provisioning Profile (CPP)", RFC 7297,
              DOI 10.17487/RFC7297, July 2014,
              <http://www.rfc-editor.org/info/rfc7297>.

Authors' Addresses

   Mohamed Boucadair
   Orange
   Rennes  35000
   France

   Email: mohamed.boucadair@orange.com


   Christian Jacquenet
   Orange
   Rennes  35000
   France

   Email: christian.jacquenet@orange.com


   Dacheng Zhang
   Huawei Technologies

   Email: zhangdacheng@huawei.com


   Panos Georgatsos
   Centre for Research and Innovation Hellas
   78, Filikis Etairias str.
   Volos, Hellas  38334
   Greece

   Phone: +302421306070
   Email: pgeorgat@iti.gr














Boucadair, et al.      Expires September 15, 2016              [Page 48]