| Rfc | 7297 |
|---|
| Title | IP Connectivity Provisioning Profile (CPP) |
|---|
| Author | M. Boucadair, C.
Jacquenet, N. Wang |
|---|
| Date | July 2014 |
|---|
| Format: | TXT, HTML |
|---|
| Status: | INFORMATIONAL |
|---|
|
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.
Copyright Notice
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
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document.
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