IP Connectivity Provisioning Profile (CPP)

Independent Submission                                      M. Boucadair
Request for Comments: 7297                                  C. Jacquenet
Category: Informational                                   France Telecom
ISSN: 2070-1721                                                  N. Wang
                                                    University of Surrey
                                                               July 2014


               IP Connectivity Provisioning Profile (CPP)

Abstract

   This document describes the Connectivity Provisioning Profile (CPP)
   and proposes a CPP template to capture IP/MPLS connectivity
   requirements to be met within a service delivery context (e.g., Voice
   over IP or IP TV).  The CPP defines the set of IP transfer parameters
   to be supported by the underlying transport network together with a
   reachability scope and bandwidth/capacity needs.  Appropriate
   performance metrics, such as one-way delay or one-way delay
   variation, are used to characterize an IP transfer service.  Both
   global and restricted reachability scopes can be captured in the CPP.

   Such a generic CPP template is meant to (1) facilitate the automation
   of the service negotiation and activation procedures, thus
   accelerating service provisioning, (2) set (traffic) objectives of
   Traffic Engineering functions and service management functions, and
   (3) improve service and network management systems with 'decision-
   making' capabilities based upon negotiated/offered CPPs.

Status of This Memo

   This document is not an Internet Standards Track specification; it is
   published for informational purposes.

   This is a contribution to the RFC Series, independently of any other
   RFC stream.  The RFC Editor has chosen to publish this document at
   its discretion and makes no statement about its value for
   implementation or deployment.  Documents approved for publication by
   the RFC Editor are not a candidate for any level of Internet
   Standard; see Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc7297.

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   Copyright (c) 2014 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
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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Connectivity Provisioning Interface (CPI) . . . . . . . .   3
     1.2.  Rationale . . . . . . . . . . . . . . . . . . . . . . . .   4
     1.3.  Reference Architecture  . . . . . . . . . . . . . . . . .   7
   2.  Scope of This Document  . . . . . . . . . . . . . . . . . . .   9
   3.  Connectivity Provisioning Profile (CPP) . . . . . . . . . . .   9
     3.1.  Customer Nodes Map  . . . . . . . . . . . . . . . . . . .   9
     3.2.  Scope . . . . . . . . . . . . . . . . . . . . . . . . . .  10
     3.3.  QoS Guarantees  . . . . . . . . . . . . . . . . . . . . .  11
     3.4.  Availability  . . . . . . . . . . . . . . . . . . . . . .  11
     3.5.  Capacity  . . . . . . . . . . . . . . . . . . . . . . . .  12
     3.6.  Conformance Traffic . . . . . . . . . . . . . . . . . . .  13
     3.7.  Overall Traffic Guarantees  . . . . . . . . . . . . . . .  13
     3.8.  Traffic Isolation . . . . . . . . . . . . . . . . . . . .  13
     3.9.  Flow Identification . . . . . . . . . . . . . . . . . . .  13
     3.10. Routing and Forwarding  . . . . . . . . . . . . . . . . .  14
     3.11. Activation Means  . . . . . . . . . . . . . . . . . . . .  15
     3.12. Invocation Means  . . . . . . . . . . . . . . . . . . . .  15
     3.13. Notifications . . . . . . . . . . . . . . . . . . . . . .  16
   4.  CPP Template  . . . . . . . . . . . . . . . . . . . . . . . .  16
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .  18
   6.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  18
   7.  Informative References  . . . . . . . . . . . . . . . . . . .  18

1.  Introduction

   This document describes the Connectivity Provisioning Profile (CPP)
   and proposes a CPP template to capture IP/MPLS connectivity
   requirements to be met within a service delivery context (e.g., Voice
   over IP, IP TV, and VPN services).

   In this document, the IP connectivity service is the IP transfer
   capability characterized by a (Source Nets, Destination Nets,
   Guarantees, Scope) tuple where "Source Nets" is a group of unicast IP
   addresses, "Destination Nets" is a group of IP unicast and/or
   multicast addresses, and "Guarantees" reflects the guarantees
   (expressed in terms of Quality Of Service (QoS), performance, and
   availability, for example) to properly forward traffic to the said
   "Destination".  Finally, the "Scope" denotes the (network) perimeter
   (e.g., between Provider Edge (PE) routers or Customer Nodes) where
   the said guarantees need to be provided.

1.1.  Connectivity Provisioning Interface (CPI)

   Figure 1 shows the various connectivity provisioning interfaces
   covered by CPP: the Customer-Network CPI, the Service-Network CPI,
   and the Network-Network CPI.  Services and applications whose
   parameters are captured by means of a CPP exchanged through the
   Service-Network CPI may be provided by the same administrative entity
   that operates the underlying network or by another entity (for
   example, a Content Provider).

                  +---------+
                  |Service A|
                  +---+-----+
                      |    +---------+
                      |CPI |Service B|
                      |    +-+-------+
                      |      |CPI
   +----------+     +-+------+-------+     +------------+
   | Customer |-----|Network Provider|-----|Peer Network|
   +----------+ CPI +----------------+ CPI +------------+

              Figure 1: Connectivity Provisioning Interfaces

   The interfaces depicted in Figure 1 can be summarized as shown in
   Figure 2.

   The Customer shown in Figure 2 may be another Network Provider (e.g.,
   an IP transit provider), a Service Provider (e.g., an IP telephony
   Service Provider) that requires the invocation of resources provided
   by a Network Provider, or an enterprise that wants to interconnect
   its various sites by subscribing to a VPN service provided by a
   Network Provider.  The proposed CPP can be used to expose, capture,
   and facilitate the negotiation of the service parameters between
   these various entities, thereby presenting a common template for
   describing the available connectivity services.

                            +----------------+
                            |   Customer     |
                            +-------+--------+
                                    + CPI
                            +-------+--------+
                            |Network Provider|
                            +----------------+

        Figure 2: CPP: Generic Connectivity Provisioning Interfaces

   In the rest of this document, "Customer" is used as a generic term to
   denote the business entity that subscribes to connectivity services
   offered by a Network Provider (see Figure 2).

1.2.  Rationale

   Procedures for the design and the operation of IP services have
   become increasingly diverse and complex.  The time it takes to
   negotiate service parameters and then proceed with the corresponding
   resource allocation can thus be measured in days, if not weeks.  Yet,
   experience has shown that the bilateral discussions that usually take
   place between a Customer and a Network Provider never rely upon some
   kind of standard checklist where the Customer would be invited to
   tick all the parameters that apply to its environment.  These
   parameters would then be negotiated with the Network Provider, as a
   function of the available resources, the Customer's expectations, the
   provider's network planning policy, etc.

   The definition of a clear interface between the service (including
   third-party applications) and the network layers would therefore
   facilitate the said discussion, thereby improving the overall service
   delivery procedure by optimizing the design of the network
   infrastructures.  Indeed, the CPP interface aims at exposing and
   characterizing, in a technology-agnostic manner, the IP transfer
   requirements to be met when invoking IP transfer capabilities of a
   network operated by a Network Provider between a set of Customer
   Nodes (e.g., Multimedia Gateway (Section 11.2.7 of [RFC2805]),
   Session Border Controller [RFC5853], etc.).

   These requirements include: reachability scope (e.g., limited scope,
   Internet-wide), direction, bandwidth requirements, QoS parameters
   (e.g., one-way delay [RFC2679], loss [RFC2680], or one-way delay
   variation [RFC3393]), protection, and high-availability guidelines
   (e.g., restoration in less than 50 ms, 100 ms, or 1 second).

   These requirements are then translated into IP/MPLS-related technical
   clauses (e.g., need for recovery means, definition of the class of
   service, need for control-plane protection, etc.).  In a later stage,
   these various clauses will be addressed by the activation of adequate
   network features and technology-specific actions (e.g., Multiprotocol
   Label Switching Traffic Engineering (MPLS-TE, [RFC3346]), Resource
   Reservation Protocol (RSVP, [RFC2205]), Open Shortest Path First
   (OSPF), Intermediate System to Intermediate System (IS-IS), etc.), by
   means of CPP-derived configuration information.

   For traffic conformance purposes, a CPP also includes flow
   identification and classification rules to be followed by
   participating nodes whenever they have to process traffic according
   to a specific service as defined by the said CPP.

   The CPP template aims to capture connectivity needs and to represent
   and value these requirements in a standardized manner.  Service- and
   Customer-specific IP provisioning rules may lead to a dramatic
   increase of the number of IP transfer classes that need to be
   (pre-)engineered in the network.  Instantiating each CPP into a
   distinct class of service should therefore be avoided for the sake of
   performance and scalability.

   Therefore, application-agnostic IP provisioning practices should be
   recommended, since the requirements captured in the CPP can be used
   to identify which network class of service is to be used to meet
   those requirements/guarantees.  From that standpoint, the CPP concept
   is meant to design a limited number of generic classes so that
   individual CPP documents, by capturing the connectivity requirements
   of services, applications, and Customers, can be easily mapped to
   these classes.

   CPP may also be used as a guideline for network dimensioning and
   planning teams of a Network Provider to ensure that appropriate
   resources (e.g., network cards, routers, link capacity, etc.) have
   been provisioned.  Otherwise, (underlying) transport networks would
   not be able to meet the objectives expressed in all CPP requests.

   Such a generic CPP template:

   o  Facilitates the automation of the service negotiation and
      activation procedures, thus improving service delivery times;

   o  Can help set Traffic Engineering function and service management
      function objectives, for example, as a function of the number of
      CPP templates to be processed over a specific period of time; and

   o  Improves service and network management systems by adding
      'decision-making' capabilities based upon negotiated/offered CPPs.

   In addition, this CPP abstraction makes a clear distinction between
   the connectivity provisioning requirements and the associated
   technology-specific rules that need to be applied by participating
   nodes and that are meant to accommodate such requirements.

   The CPP defines the set of IP/MPLS transfer guarantees to be offered
   by the underlying transport network together with a reachability
   scope and capacity needs.  Appropriate performance metrics, such as
   one-way delay or one-way delay variation, are used to characterize
   the IP transfer service.  Guarantees related to availability and
   resiliency are also included in the CPP.

   The CPP can be used in an integrated business environment (where the
   service and network infrastructures are managed by the same
   administrative entity) or another business environment (where an
   administrative entity manages the service while another manages the
   network infrastructure).  In the following sections, no assumption is
   made about the business environment (integrated or not).

   Service differentiation at the network layer can be enforced by
   tweaking various parameters that belong to distinct dimensions (e.g.,
   forwarding, routing, processing of incoming traffic, traffic
   classification, etc.).  This document does not make any assumption on
   how network services are implemented within a networking
   infrastructure.

   Activating unicast or multicast capabilities to deliver a
   connectivity service can be explicitly requested by a Customer in a
   CPP or can be an engineering decision of a Network Provider based on
   the analysis of the Customer connectivity provisioning requirements.

   Examples of CPP usage include the northbound interface introduced by
   the Application-Based Network Operations (ABNO) framework [NET-OPS]
   and the technique for exposing network services and their
   characteristics defined in [RFC7149].

1.3.  Reference Architecture

   Customer Nodes belong to a Customer (including corporate Customers)
   or a service infrastructure (see Figure 1).  In some contexts,
   Customer Nodes can be provided and managed by the Network Provider.
   The connectivity between these Customer Nodes reflects the IP
   transfer capability implemented thanks to the allocation of a set of
   IP resources.  IP transfer capabilities are considered by higher-
   layer services (such as transport- and application-layer services) as
   black boxes.  Appropriate notifications and reports would be
   communicated (through dedicated means) to Customer Nodes to assess
   the compliance of the experienced IP transfer service against what
   has been negotiated with the corresponding CPP.  These notifications
   may also be used to assess the efficiency of the various policies
   enforced in the networking infrastructure to accommodate the
   requirements detailed in the CPP.

   The CPP reference architectures are depicted in Figures 3, 4, and 5.

   The Customer infrastructure can be connected over networking
   infrastructures managed by one or several Network Providers.

          .--. .--.. .--..--.
         (                   '.--.
      .-.' Customer Infrastructure'.-.
      (                                )
     +-------------+               +-------------+
     |Customer Node|.--. .--.. .--.|Customer Node|
     +-------------+               +-------------+
           |                            |
    +--------------+             +--------------+
    |Provider Node |.--. .--.. . |Provider Node |
    +--------------+             +--------------+
          (                             )
        .-.'         Network            '.-.
        (                                   )
         (      .     .    .    .    .    .)
           '.-_-.'.-_-._.'.-_-.'.-_-.'.--.'

    Figure 3: Reference Architecture: Connectivity Service Provided by
      the Same Network Provider Using Distinct Interconnection Nodes

          .--. .--.. .--..--.
         (                   '.--.
      .-.' Customer Infrastructure'.-.
      (                                )
     +-------------+               +-------------+
     |Customer Node|.--. .--.. .--.|Customer Node|
     +-------------+               +-------------+
           |                            |
        +-----------------------------------+
        |        Provider Node              |
        +-----------------------------------+
          (                             )
        .-.'         Network            '.-.
        (                                   )
         (      .     .    .    .    .    .)
           '.-_-.'.-_-._.'.-_-.'.-_-.'.--.'

    Figure 4: Reference Architecture: Connectivity Service Provided by
       the Same Network Provider Using a Single Interconnection Node

          .--. .--.. .--..--.
         (                   '.--.
      .-.' Customer Infrastructure'.-.
      (                                )
     +-------------+               +-------------+
     |Customer Node|.--. .--.. .--.|Customer Node|
     +-------------+               +-------------+
           |                            |
    +--------------+             +--------------+
    |Provider Node |             |Provider Node |
    +--------------+             +--------------+
     (            .--.)           (           .--.)
   .-.'   Network A  '.-.      .-.'   Network B  '.-.
     (                  )      (                    )
     (.     .    .    .)        (.     .    .     .)
      '.-_-.'.-_-._..'             '.-_-.'.-_-._..'

    Figure 5: Reference Architecture: Connectivity Services Provided by
                        Distinct Network Providers

2.  Scope of This Document

   This document details the clauses of the CPP.  Candidate protocols
   (e.g., [CPNP]) that can be used to negotiate and enforce a given CPP
   are not discussed in this document.

   In addition to CPP clauses, other clauses may be included in an
   agreement between a Customer and a Provider (e.g., contact point,
   escalation procedure, incidents management, billing, etc.).  It is
   out of the scope of this document to detail all those additional
   clauses.

   Examples of how to translate CPP clauses into specific policies are
   provided for illustration purposes.  It is out of the scope of this
   document to provide an exhaustive list of the technical means to meet
   the objectives detailed in a CPP.

   CPP was mainly designed to target IP connectivity services.
   Nevertheless, it can be used for other non-IP transport schemes.  It
   is out of the scope of this document to assess the applicability of
   CPP to these non-IP schemes.

   This document covers both unicast and multicast connectivity
   services.  Both Any-Source Multicast (ASM, [RFC1112]) and Source-
   Specific Multicast (SSM, [RFC4607]) modes can be captured in a CPP.

3.  Connectivity Provisioning Profile (CPP)

   A CPP can be seen as the inventory of connectivity provisioning
   requirements with regard to the IP transfer service.  CPP clauses are
   elaborated in the following sub-sections.  The CPP template is
   provided in Section 4.

3.1.  Customer Nodes Map

   A CPP must include the list of Customer Nodes (e.g., Customer Edges
   (CEs)) to be connected to the underlying IP transport network.

   These nodes should be unambiguously identified (e.g., using a unique
   Service_identifier, Media Access Control (MAC) addresses, etc.).  For
   each Customer Node, a border link or a node that belongs to the
   domain that connects the Customer Nodes should be identified.

   This clause can specify geolocation information of Customer Nodes.

   Based on the location of the Customer Node, appropriate operations to
   retrieve the corresponding border link or "Provider Node" (e.g., PE)
   should be undertaken.  This operation can be manual or automated.

   A "service site" would be located behind a given Customer Node.  A
   site identifier may be captured in the CPP for the provisioning of
   managed VPN services [RFC4026], for instance, Site_identifier.

   A Customer Node may be connected to several Provider Nodes.  Multiple
   Customer Nodes may be connected to the same Provider Node as shown in
   Figure 4.

3.2.  Scope

   The scope clause specifies the reachability of each of the involved
   Customer Nodes, from both incoming and outgoing traffic perspectives,
   thereby yielding specific traffic directionality considerations.  It
   is defined as an unidirectional parameter.  Both directions should be
   described in the CPP.

   The reachability scope specifies the set of destination prefixes that
   can be reached from a given Customer site (identified by a group of
   source prefixes).  Both global and restricted reachability scopes can
   be captured in the CPP.  A global reachability scope means that a
   Customer site can reach any destination in the Internet and can be
   reached from any remote host.  A restricted reachability scope means
   no global reachability is allowed; only a set of destinations can be
   reached from a Customer site, and/or only a set of sources can reach
   the Customer site.  Both incoming and outgoing reachability scopes
   are specified in the CPP.

   Both IPv4 and IPv6 reachability scopes may be specified.

   The reachability scope clause can include multicast and/or unicast
   addresses.  For SSM, a group of unicast source addresses can be
   specified in addition to destination multicast addresses.

   The scope clause can also be used to delimit a topological (or
   geographical) network portion beyond which the performance and
   availability guarantees do not apply.  A scope may be defined by a
   set of "Ingress" points and "Egress" points.  Several types may be
   considered, such as:

   (1) "1:1" Pipe model.  Only point-to-point communications are
       allowed.

   (2) "1:N" Hose model.  Only communications from one site towards a
       set of destinations are allowed.

   (3) "1:any" Unspecified hose model.  All outbound communications are
       allowed.

   The Ingress and Egress points could be Customer Nodes / Provider
   Nodes or external nodes, provided that these nodes are unambiguously
   identified (e.g., IPv6 prefix), or a set of IP destinations.

3.3.  QoS Guarantees

   QoS guarantees denote a set of IP transfer performance metrics that
   characterize the quality of the IP transfer treatment to be
   experienced (when crossing an IP transport infrastructure) by a flow
   issued from or forwarded to a (set of) "Customer Node(s)".

   IP performance metrics can be expressed as qualitative or
   quantitative parameters (both quantitative and qualitative guarantees
   cannot be specified in the same CPP).  Quantitative guarantees may be
   specified as an average value, as a maximum bound, or as a percentile
   over an interval of measurements that should be indicated in the
   measurement method.

   Several performance metrics have been defined, such as:

   o  Traffic Loss [RFC2680]

   o  One-way delay [RFC2679]

   o  One-way delay variation [RFC3393]

   These parameters may be specific to a given path or a given scope
   (e.g., between two Customer Nodes).  IP performance metric values
   indicated in a CPP should reflect the measurement between a set of
   Customer Nodes or between a Customer Node and a set of Provider
   Nodes.

   Quantitative guarantees can only be specified for in-profile traffic
   (i.e., up to a certain traffic rate).  A CPP can include throughput
   guarantees; when specified, these guarantees are equivalent to
   quantitative or qualitative loss guarantees.

   The Meta-QoS-Class concept can be used when qualitative metrics are
   used [RFC5160].

3.4.  Availability

   This clause specifies the percentage of the time during which the
   agreed IP performance guarantees apply.  The clause can be expressed
   as a maximum or an average.  The exact meaning of the clause value is
   defined during the CPP negotiation process.

   The guarantees cover both QoS deterioration (i.e., IP transfer
   service is available, but it is below the agreed performance bounds),
   physical failures, or service unavailability in general.  In order to
   meet the availability guarantees, several engineering practices may
   be enforced at the border between the Customer and the Network
   Provider, such as multi-homing designs.

   The following mechanisms are provided as examples to show that
   different technical options may be chosen to meet the service
   availability objectives:

   o  When an Interior Gateway Protocol (IGP) instance is running
      between the "Customer Node" and the "Provider Node", activate a
      dedicated protocol, such as Bidirectional Forwarding Detection
      (BFD, [RFC5881][RFC5883]), to control IGP availability and to
      ensure sub-second IGP adjacency failure detection.

   o  Use of the Label Switched Path Ping (LSP Ping) capability to
      detect LSP availability (check whether the LSP is in place or not)
      [RFC4379][RFC6424][RFC6425][RFC6426][RFC6829].

   o  Pre-install backup LSPs for fast-reroute purposes when an MPLS
      network connects Customer Nodes [RFC4090].

   o  Enable Virtual Router Redundancy Protocol (VRRP, [RFC5798]).

   o  Enable IP Fast Reroute features (e.g., [RFC5286] or [RFC6981]).

3.5.  Capacity

   This clause characterizes the required capacity to be provided by the
   underlying IP transport network.  This capacity is bound to a defined
   "Scope" (see Section 3.2) and IP transfer performance guarantees (see
   Sections 3.3 and 3.4).

   The capacity may be expressed for both traffic directions (i.e.,
   incoming and outgoing) and for every border link.  The capacity
   clause defines the limits of the application of quantitative
   guarantees.

   It is up to the administrative entity, which manages the IP transport
   network, to appropriately dimension its network [RFC5136] to meet the
   capacity requirements expressed in all negotiated CPPs.

3.6.  Conformance Traffic

   When capacity information (see Section 3.5) is included in the CPP,
   requirements for out-of-profile traffic treatment need to be also
   expressed in the CPP.

   Shaping/policing filters may be applied so as to assess whether
   traffic is within the capacity profile or out of profile.  Out-of-
   profile traffic may be discarded or assigned another class (e.g.,
   using Lower Effort Per-Domain Behavior (LE PDB) [RFC3662]).

   Packet MTU conditions may also be indicated in the CPP.

3.7.  Overall Traffic Guarantees

   Overall traffic guarantees are defined when the Capacity
   (Section 3.5) and Conformance Traffic (Section 3.6) clauses are not
   specified.  Or, if they are actually specified, then out-of-profile
   traffic is assigned another class of service but is not discarded.
   Such guarantees can only be qualitative delay and/or qualitative loss
   or throughput guarantees.

   If overall traffic guarantees are not specified, best effort
   forwarding is implied.

3.8.  Traffic Isolation

   This clause indicates if the traffic issued by or destined to
   "Customer Nodes" should be isolated when crossing the IP transport
   network.  This clause can also be used to specify additional security
   protection requirements (including privacy protection requirements).

   This clause can then be translated into VPN policy provisioning
   information, such as the information pertaining to the activation of
   dedicated tunnels using IPsec, BGP/MPLS VPN facilities [RFC4364], or
   a combination thereof.  The activation of such features should be
   consistent with the availability and performance guarantees that have
   been negotiated.

3.9.  Flow Identification

   To identify the flows that need to be handled within the context of a
   given CPP, flow identifiers should be indicated in the CPP.  Flow
   identifiers are used for traffic classification purposes.  An example
   of packet classifier is defined in [RFC2475].

   A flow identifier may be composed of (but not limited to) the
   following parameters:

   o  Source IP address,

   o  Source port number,

   o  Destination IP address,

   o  Destination port number,

   o  Type of Service (ToS) or Differentiated Services Code Point (DSCP)
      field,

   o  Tail-end tunnel endpoint, or

   o  Any combination thereof.

   Distinct treatments may be implemented for elastic and non-elastic
   traffic (e.g., see the "Constraints on traffic" clause defined in
   [RFC5160]).

   Flow classification rules may be specific to a given link or may be
   applied for a group or all border links.  This should be clearly
   captured in the CPP.

   Some practices such as DSCP re-marking may be indicated in the CPP.
   Re-marking action is under the responsibility of underlying nodes
   that intervene to deliver the connectivity service.  Re-marking can
   be enforced for both outgoing and incoming traffic received from or
   destined to Customer Nodes.  These re-marking actions must not alter
   the service-specific marking integrity (e.g., VPN service).

   This clause may specify policies (e.g., DSCP re-marking) to be
   enforced at the egress nodes on packets received from Customer Nodes.
   If no such policy is specified, the Network Provider enforces its
   local policies (e.g., clear DSCP marking) on packets leaving its
   administrative domain.

3.10.  Routing and Forwarding

   This clause is used to specify outsourced routing actions, such as
   installing dedicated routes to convey the traffic to its (service)
   destination.  These dedicated routes may be computed, selected, and
   installed for Traffic Engineering or resilience purposes.  For
   Traffic Engineering, these paths can be used to intelligently divert
   traffic away from some nodes/links that may potentially suffer from
   congestion or avoid crossing competitors' networks.  For resilience,
   backup paths are typically pre-installed in order to bypass nodes/
   links under protection.

   This clause is also used to specify intermediate functions that must
   be invoked in the forwarding path (e.g., redirect the traffic to a
   firewall, invoke topology hiding features, etc.) or specify
   geographic routing restrictions.

   A requirement for setting up a logical routing topology [RFC4915]
   [RFC5120] may also be considered, e.g., to facilitate the management
   of the nodes that are involved in the forwarding of the traffic as
   defined in the CPP.

   This practice should be indicated in the CPP; otherwise, path
   computation is left to the underlying IP routing capabilities.  The
   forwarding behavior (e.g., Per-Domain Behavior (PDB) [RFC3086]) may
   also be specified in a CPP but remains optional.  If indicated,
   consistency with the IP performance bounds defined in the CPP should
   be carefully ensured.

   For illustration purposes, a routing policy would avoid satellite
   links for Voice over IP (VoIP) deployments since this may degrade the
   offered service.

3.11.  Activation Means

   This clause indicates the required action(s) to be undertaken to
   activate access to the IP connectivity service.

   Examples of these actions would be the activation of an IGP instance,
   the establishment of a BGP [RFC4271] or Multiprotocol BGP (MP-BGP)
   session [RFC4760], Protocol Independent Multicast (PIM, [RFC4601]),
   etc.

3.12.  Invocation Means

   Two types are defined:

   Implicit:  This clause indicates that no explicit means to invoke the
      connectivity service is required.  Access to the connectivity
      service is primarily conditioned by the requested network
      capacity.

   Explicit:  This clause indicates the need for explicit means to
      access the connectivity service.  Examples of such means include
      the use of RSVP [RFC2205], RSVP-TE [RFC3209], Internet Group
      Management Protocol (IGMP, [RFC3376]), or Multicast Listener
      Discovery (MLD, [RFC3810]).  Appropriate admission control
      procedures [RFC6601] would have to be enforced, e.g., to check
      whether the capacity actually used is not above the agreed
      threshold.

3.13.  Notifications

   For operation purposes (e.g., supervision) and service fulfillment
   needs, management platforms need to be notified about critical events
   that may impact the delivery of the service.

   The notification procedure should be indicated in the CPP.  This
   procedure may specify the type of information to be sent, the
   interval, the data model, etc.

   Notifications can be sent to the management platform by using Simple
   Network Management Protocol (SNMP, [RFC3416]), Syslog notifications
   [RFC5424], Connectivity Provisioning Negotiation Protocol (CPNP)
   signals [CPNP], Network Configuration Protocol (NETCONF) Event
   Notifications [RFC5277], or a phone call!

4.  CPP Template

   Figure 6 provides the Routing Backus-Naur Form (RBNF, [RFC5511])
   format of the CPP template.

   A CPP document includes several connectivity provisioning components;
   each of these is structured as a CPP.  The CPP may include additional
   optional information elements such as metrics used for Service
   Assurance purposes, activation schedule, etc.

   <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>
                              <Optional Information Element> ...
   <Customer Nodes Map> ::=  <Customer Node> ...
   <Customer Node> ::=  <IDENTIFIER>
                        <LINK_IDENTIFIER>
                        <LOCALIZATION>

                          Figure 6: CPP Template

   The description of these clauses is provided in Section 3.

   The CPP may also include a Customer's administrative information,
   such as a name and other contact details.  An example of the RBNF
   format of the Customer's information is shown in Figure 7.

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

                   Figure 7: Customer Description Clause

   The CPP may include administrative information of the Network
   Provider too (name, Autonomous System number(s), and other contact
   details).  An example of the RBNF format of the provider's
   information is shown in Figure 8.

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

                   Figure 8: Provider Description Clause

5.  Security Considerations

   This document does not define an architecture or specify a protocol.
   Yet, the means to provide guarantees about the identity of a Customer
   and its ability to expose connectivity requirements to a Network
   Provider through a CPP need to be investigated.  Likewise, the means
   to provide guarantees about the identity of a Network Provider and
   the ability to expose its capabilities, let alone capture the
   requirements of a Customer through a CPP, should be carefully
   studied.

   CPP documents should be protected against illegitimate modifications
   (e.g., modification, withdrawal); authorization means should be
   enabled.  These means are deployment-specific.

   The Network Provider must enforce means to protect privacy-related
   information captured in a CPP document [RFC6462].  In particular,
   this information must not be revealed to external parties without the
   consent of Customers.  Network Providers should enforce policies to
   make Customer fingerprinting more difficult to achieve.  For more
   discussion about privacy, refer to [RFC6462] and [RFC6973].

6.  Acknowledgements

   Some of the items in this document are the result of several
   discussions with E. Mykoniati and D. Griffin.  Special thanks to
   them.

   Many thanks to P. Georgatsos for the discussions and the detailed
   review of this document.

   Thanks to S. Shah, G. Huston, D. King, and S. Bryant for reviewing
   the document and providing useful comments.

7.  Informative References

   [CPNP]     Boucadair, M., Jacquenet, C., and D. Zhang, "Connectivity
              Provisioning Negotiation Protocol (CPNP)", Work in
              Progress, June 2014.

   [NET-OPS]  King, D. and A. Farrel, "A PCE-based Architecture for
              Application-based Network Operations", Work in Progress,
              February 2014.

   [RFC1112]  Deering, S., "Host extensions for IP multicasting", STD 5,
              RFC 1112, August 1989.

   [RFC2205]  Braden, B., Zhang, L., Berson, S., Herzog, S., and S.
              Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1
              Functional Specification", RFC 2205, September 1997.

   [RFC2475]  Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z.,
              and W. Weiss, "An Architecture for Differentiated
              Services", RFC 2475, December 1998.

   [RFC2679]  Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way
              Delay Metric for IPPM", RFC 2679, September 1999.

   [RFC2680]  Almes, G., Kalidindi, S., and M. Zekauskas, "A One-way
              Packet Loss Metric for IPPM", RFC 2680, September 1999.

   [RFC2805]  Greene, N., Ramalho, M., and B. Rosen, "Media Gateway
              Control Protocol Architecture and Requirements", RFC 2805,
              April 2000.

   [RFC3086]  Nichols, K. and B. Carpenter, "Definition of
              Differentiated Services Per Domain Behaviors and Rules for
              their Specification", RFC 3086, April 2001.

   [RFC3209]  Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
              and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
              Tunnels", RFC 3209, December 2001.

   [RFC3346]  Boyle, J., Gill, V., Hannan, A., Cooper, D., Awduche, D.,
              Christian, B., and W. Lai, "Applicability Statement for
              Traffic Engineering with MPLS", RFC 3346, August 2002.

   [RFC3376]  Cain, B., Deering, S., Kouvelas, I., Fenner, B., and A.
              Thyagarajan, "Internet Group Management Protocol, Version
              3", RFC 3376, October 2002.

   [RFC3393]  Demichelis, C. and P. Chimento, "IP Packet Delay Variation
              Metric for IP Performance Metrics (IPPM)", RFC 3393,
              November 2002.

   [RFC3416]  Presuhn, R., "Version 2 of the Protocol Operations for the
              Simple Network Management Protocol (SNMP)", STD 62, RFC
              3416, December 2002.

   [RFC3662]  Bless, R., Nichols, K., and K. Wehrle, "A Lower Effort
              Per-Domain Behavior (PDB) for Differentiated Services",
              RFC 3662, December 2003.

   [RFC3810]  Vida, R. and L. Costa, "Multicast Listener Discovery
              Version 2 (MLDv2) for IPv6", RFC 3810, June 2004.

   [RFC4026]  Andersson, L. and T. Madsen, "Provider Provisioned Virtual
              Private Network (VPN) Terminology", RFC 4026, March 2005.

   [RFC4090]  Pan, P., Swallow, G., and A. Atlas, "Fast Reroute
              Extensions to RSVP-TE for LSP Tunnels", RFC 4090, May
              2005.

   [RFC4271]  Rekhter, Y., Li, T., and S. Hares, "A Border Gateway
              Protocol 4 (BGP-4)", RFC 4271, January 2006.

   [RFC4364]  Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
              Networks (VPNs)", RFC 4364, February 2006.

   [RFC4379]  Kompella, K. and G. Swallow, "Detecting Multi-Protocol
              Label Switched (MPLS) Data Plane Failures", RFC 4379,
              February 2006.

   [RFC4601]  Fenner, B., Handley, M., Holbrook, H., and I. Kouvelas,
              "Protocol Independent Multicast - Sparse Mode (PIM-SM):
              Protocol Specification (Revised)", RFC 4601, August 2006.

   [RFC4607]  Holbrook, H. and B. Cain, "Source-Specific Multicast for
              IP", RFC 4607, August 2006.

   [RFC4760]  Bates, T., Chandra, R., Katz, D., and Y. Rekhter,
              "Multiprotocol Extensions for BGP-4", RFC 4760, January
              2007.

   [RFC4915]  Psenak, P., Mirtorabi, S., Roy, A., Nguyen, L., and P.
              Pillay-Esnault, "Multi-Topology (MT) Routing in OSPF", RFC
              4915, June 2007.

   [RFC5120]  Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi
              Topology (MT) Routing in Intermediate System to
              Intermediate Systems (IS-ISs)", RFC 5120, February 2008.

   [RFC5136]  Chimento, P. and J. Ishac, "Defining Network Capacity",
              RFC 5136, February 2008.

   [RFC5160]  Levis, P. and M. Boucadair, "Considerations of Provider-
              to-Provider Agreements for Internet-Scale Quality of
              Service (QoS)", RFC 5160, March 2008.

   [RFC5277]  Chisholm, S. and H. Trevino, "NETCONF Event
              Notifications", RFC 5277, July 2008.

   [RFC5286]  Atlas, A. and A. Zinin, "Basic Specification for IP Fast
              Reroute: Loop-Free Alternates", RFC 5286, September 2008.

   [RFC5424]  Gerhards, R., "The Syslog Protocol", RFC 5424, March 2009.

   [RFC5511]  Farrel, A., "Routing Backus-Naur Form (RBNF): A Syntax
              Used to Form Encoding Rules in Various Routing Protocol
              Specifications", RFC 5511, April 2009.

   [RFC5798]  Nadas, S., "Virtual Router Redundancy Protocol (VRRP)
              Version 3 for IPv4 and IPv6", RFC 5798, March 2010.

   [RFC5853]  Hautakorpi, J., Camarillo, G., Penfield, R., Hawrylyshen,
              A., and M. Bhatia, "Requirements from Session Initiation
              Protocol (SIP) Session Border Control (SBC) Deployments",
              RFC 5853, April 2010.

   [RFC5881]  Katz, D. and D. Ward, "Bidirectional Forwarding Detection
              (BFD) for IPv4 and IPv6 (Single Hop)", RFC 5881, June
              2010.

   [RFC5883]  Katz, D. and D. Ward, "Bidirectional Forwarding Detection
              (BFD) for Multihop Paths", RFC 5883, June 2010.

   [RFC6424]  Bahadur, N., Kompella, K., and G. Swallow, "Mechanism for
              Performing Label Switched Path Ping (LSP Ping) over MPLS
              Tunnels", RFC 6424, November 2011.

   [RFC6425]  Saxena, S., Swallow, G., Ali, Z., Farrel, A., Yasukawa,
              S., and T. Nadeau, "Detecting Data-Plane Failures in
              Point-to-Multipoint MPLS - Extensions to LSP Ping", RFC
              6425, November 2011.

   [RFC6426]  Gray, E., Bahadur, N., Boutros, S., and R. Aggarwal, "MPLS
              On-Demand Connectivity Verification and Route Tracing",
              RFC 6426, November 2011.

   [RFC6462]  Cooper, A., "Report from the Internet Privacy Workshop",
              RFC 6462, January 2012.

   [RFC6601]  Ash, G. and D. McDysan, "Generic Connection Admission
              Control (GCAC) Algorithm Specification for IP/MPLS
              Networks", RFC 6601, April 2012.

   [RFC6829]  Chen, M., Pan, P., Pignataro, C., and R. Asati, "Label
              Switched Path (LSP) Ping for Pseudowire Forwarding
              Equivalence Classes (FECs) Advertised over IPv6", RFC
              6829, January 2013.

   [RFC6973]  Cooper, A., Tschofenig, H., Aboba, B., Peterson, J.,
              Morris, J., Hansen, M., and R. Smith, "Privacy
              Considerations for Internet Protocols", RFC 6973, July
              2013.

   [RFC6981]  Bryant, S., Previdi, S., and M. Shand, "A Framework for IP
              and MPLS Fast Reroute Using Not-Via Addresses", RFC 6981,
              August 2013.

   [RFC7149]  Boucadair, M. and C. Jacquenet, "Software-Defined
              Networking: A Perspective from within a Service Provider
              Environment", RFC 7149, March 2014.

Authors' Addresses

   Mohamed Boucadair
   France Telecom
   Rennes  35000
   France

   EMail: mohamed.boucadair@orange.com


   Christian Jacquenet
   France Telecom
   Rennes  35000
   France

   EMail: christian.jacquenet@orange.com


   Ning Wang
   University of Surrey
   Guildford
   UK

   EMail: n.wang@surrey.ac.uk