Network Working Group M. Boucadair
Internet Draft C. Jacquenet
Document: draft-jacquenet-ip-fwd-pib-01.txt France Telecom
Category: Experimental June 2003
Expires December 2003
An IP Forwarding Policy Information Base
<draft-jacquenet-ip-fwd-pib-01.txt>
Status of this Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC 2026 [1].
Internet-Drafts are working documents of the Internet Engineering
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Abstract
This draft specifies a set of Policy Rule Classes (PRC) for the
enforcement of an IP forwarding policy by network devices. Instances
of such classes reside in a virtual information store, which is
called the IP Forwarding Policy Information Base (PIB). The
corresponding IP forwarding policy provisioning data are intended for
use by a COPS-PR IP TE Client-Type, and they complement the PRC
classes that have been defined in the Framework PIB.
Table of Contents
1. Introduction...............................................2
2. Conventions used in this document..........................3
3. Changes since the Previous Version.........................3
4. PIB Overview...............................................3
5. The IP Forwarding Policy Information Base..................4
6. Security Considerations....................................9
7. References.................................................9
8. Acknowledgments...........................................10
9. Authors' Addresses........................................10
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10. Full Copyright Statement..................................11
1. Introduction
The deployment of value-added IP services over the Internet has
become one of the most competing challenges for service providers, as
well as a complex technical issue.
Within the context of network resource provisioning and allocation,
the Common Open Policy Service protocol (COPS, [2]) and its usage for
the support of Policy Provisioning ([3]) is one of the most promising
candidate protocols that should help service providers in dynamically
enforcing IP routing and traffic engineering policies.
An IP routing/TE policy consists in appropriately provisioning and
allocating/de-allocating the switching and the transmission resources
of an IP network (i.e. the routers and the links that connect these
routers, respectively), according to e.g. rate, one-way delay, inter-
packet delay variation, etc.) that have been possibly negotiated
between the customers and the service providers, and according to (a
set of)routing metrics, which can also reflect the network
conditions.
Thus, the enforcement of IP routing/TE policies yields the need for
an introduction of a high level of automation for the dynamic
provisioning of the configuration data that will be taken into
account by the routers to select the appropriate IP routes.
Within the context of this document, the actual enforcement of an IP
forwarding policy is primarily based upon the activation of both
intra- and inter-domain dynamic routing protocols that will be
activated by the routers to select, install, maintain and possibly
withdraw IP routes.
Such routes have been selected so that they comply as much as
possible with the aforementioned QoS requirements and/or specific
routing constraints, possibly depending on the type of traffic that
will be conveyed along these routes.
It is therefore necessary to provide the route selection processes
with the information that will depict the routing policies that are
to be enforced within a domain and, whenever appropriate, the
aforementioned constraints and metrics, given the dynamic routing
protocols actually support traffic engineering capabilities for the
calculation and the selection of such routes.
Some of these capabilities are currently being specified in [4] and
[5] for the OSPF (Open Shortest Path First) and the IS-IS
(Intermediate System to Intermediate System routing protocol, [6])
interior routing protocols respectively, while there is a comparable
effort for the BGP4 (Border Gateway Protocol, version 4) protocol, as
described in [7], for example.
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To provide the route selection processes with the aforementioned
information, one possibility is to use the COPS-PR protocol, together
with a collection of policy provisioning data that will be stored in
a virtual information store, called a Policy Information Base.
This draft describes a collection of Policy Rule Classes that will be
stored and dynamically maintained in an IP forwarding PIB. The "rule"
and "role" concepts, which have been defined in [8], are adopted by
this document to distribute the IP routing policy provisioning data
over the COPS-PR protocol.
The corresponding IP forwarding policy provisioning data are intended
for use by a COPS-PR IP TE Client-Type ([9]), and they complement the
PRC classes that have been defined in the Framework PIB ([10]).
This document is organized as follows:
- Section 4 provides an overview of the organization of the IP
forwarding PIB,
- Section 5 provides a description of the PRC classes of the IP
forwarding PIB, according to the semantics of the Structure of
Policy Provisioning Information (SPPI, [11]).
2. Conventions used in this document
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 [12].
3. Changes since the Previous Version
- Some elaboration has been provided as far as the interaction with
other relevant PIB specification efforts is concerned,
- The references section has been updated.
4. PIB Overview
The dynamic enforcement of an IP forwarding policy relies upon the
activation of intra- and inter-domain routing protocols that will
have the ability to take into account configuration information for
the computation and the selection of routes, which will comply as
much as possible with the constraints and requirements that MAY have
been contractually defined between customers and service providers.
This document specifies an IP forwarding PIB that mainly aims at
storing and maintaining the information related to the IP routes that
have been installed in the routers' Forwarding Information Bases, so
that service providers maintain and update the adequate knowledge of
the network's resources availability, from an IP routing perspective.
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As such, this PIB has been designed so that it SHOULD be gracefully
complemented by PIB modules that will reflect the IGP- and BGP-
inferred routing policies to be enforced, in terms of cost metrics'
values to be assigned and updated whenever needed.
Also, the accounting PIB module which is described in [13] aims at
providing the most accurate feedback (to service providers) on how
efficient the enforcement of a given IP forwarding policy (as
specified in this document) actually is.
The choice of this PIB organization is basically twofold:
- Make the PIB implementation simple,
- Provide the appropriate granularity of policy provisioning data
that will be manipulated according to the requirements and
technical choices of service providers.
Therefore, the IP forwarding PIB is currently organized into the
following provisioning classes:
1. The Forwarding Classes (ipFwdClasses): the information
contained in these classes is meant to provide a detailed
description of the IP routes as they have been selected by the
routers of a given domain,
2. The Statistics Classes (ipFwdStatsClasses): the information
contained in these classes is meant to provide statistics on
the use of the IP routes currently depicted in the IP
forwarding PIB.
5. The IP Forwarding Policy Information Base
IP-FWD-PIB PIB-DEFINITIONS ::= BEGIN
IMPORTS
Unsigned32, Integer32, MODULE-IDENTITY,
MODULE-COMPLIANCE, OBJECT-TYPE, OBJECT-GROUP
FROM COPS-PR-SPPI
InstanceId, ReferenceId, Prid, TagId
FROM COPS-PR-SPPI-TC
InetAddress, InetAddressType
FROM INET-ADDRESS-MIB
Count, TEXTUAL-CONVENTION
FROM ACCT-FR-PIB-TC
TruthValue, TEXTUAL-CONVENTION
FROM SNMPv2-TC
RoleCombination, PrcIdentifier
FROM FRAMEWORK-ROLE-PIB
SnmpAdminString
FROM SNMP-FRAMEWORK-MIB;
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ipFwdPib MODULE-IDENTITY
SUBJECT-CATEGORIES { tbd } -- IP TE client-type to be
-- assigned by IANA
LAST-UPDATED "200301220900Z"
ORGANIZATION "France Telecom"
CONTACT-INFO "
Mohamed Boucadair
France Telecom R & D
42, rue des Coutures
BP 6243
14066 CAEN CEDEX 04
France
Phone: +33 2 31 75 92 31
E-Mail: mohamed.boucadair@francetelecom.com"
DESCRIPTION
"The PIB module containing a set of policy rule classes
that describe the IP routes that have been computed by
means of routing/TE policy enforcement, as well as
route traffic statistics."
REVISION "200306251000Z"
DESCRIPTION
"Initial version."
::= { pib tbd } -- tbd to be assigned by IANA
ipFwdClasses OBJECT IDENTIFIER ::= { ipFwdPib 1 }
ipFwdStatsClasses OBJECT IDENTIFIER ::= { ipFwdPib 2 }
--
-- Forwarding classes. The information contained in these classes
-- is meant to provide a detailed description of the available IP
-- routes. One table has been specified so far, but there is room
-- for depicting different kinds of routes, like MPLS (MultiProtocol
-- Label Switching, ([14]) LSP (Label switched Paths) paths.
--
--
--
--
-- The ipFwdTable
--
ipFwdTable OBJECT-TYPE
SYNTAX SEQUENCE OF ipRouteEntry
PIB-ACCESS notify
STATUS current
DESCRIPTION
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"This table describes the IP routes that are installed
in the forwarding tables of the routers."
::= { ipFwdClasses 1 }
ipRouteEntry OBJECT-TYPE
SYNTAX ipRouteEntry
STATUS current
DESCRIPTION
"A particular route to a particular destination."
PIB-INDEX { ipRoutePrid }
UNIQUENESS { ipRouteDest,
ipRouteMask,
ipRoutePhbId,
ipRouteNextHopAddress
ipRouteNextHopMask
ipRouteIfIndex }
::= { ipFwdTable 1 }
ipRouteEntry ::= SEQUENCE {
ipRoutePrid InstanceId,
ipRouteDestAddrType InetAddressType,
ipRouteDest InetAddress,
ipRouteMask Unsigned32,
ipRouteNextHopAddrType InetAddressType,
ipRouteNextHopAddress InetAddress,
ipRouteNextHopMask Unsigned32,
ipRoutePhbId Integer32,
ipRouteOrigin Integer32,
ipRouteIfIndex Unsigned32
}
ipRoutePrid OBJECT-TYPE
SYNTAX InstanceId
STATUS current
DESCRIPTION
"An integer index that uniquely identifies this route
entry among all the route entries."
::= { ipRouteEntry 1 }
ipRouteDestAddrType OBJECT-TYPE
SYNTAX InetAddressType
STATUS current
DESCRIPTION
"The address type enumeration value ([15]) used to
specify the type of a route's destination IP address."
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::= { ipRouteEntry 2 }
ipRouteDest OBJECT-TYPE
SYNTAX InetAddress
STATUS current
DESCRIPTION
"The IP address to match against the packet's
destination address."
::= { ipRouteEntry 3 }
ipRouteMask OBJECT-TYPE
SYNTAX Unsigned32 (0..128)
STATUS current
DESCRIPTION
"Indicates the length of a mask for the matching of the
destination IP address. Masks are constructed by
setting bits in sequence from the most-significant bit
downwards for ipRouteMask bits length. All other bits
in the mask, up to the number needed to fill the length
of the address ipRouteDest are cleared to zero. A zero
bit in the mask then means that the corresponding bit
in the address always matches."
::= { ipRouteEntry 4 }
ipRouteNextHopAddrType OBJECT-TYPE
SYNTAX InetAddressType
STATUS current
DESCRIPTION
"The address type enumeration value used to specify the
type of the next hop's IP address."
::= { ipRouteEntry 5 }
ipRouteNextHopAddress OBJECT-TYPE
SYNTAX InetAddress
STATUS current
DESCRIPTION
"On remote routes, the address of the next router en
route; Otherwise, 0.0.0.0."
::= { ipRouteEntry 6 }
ipRouteNextHopMask OBJECT-TYPE
SYNTAX Unsigned32 (0..128)
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STATUS current
DESCRIPTION
"Indicates the length of a mask for the matching of the
next hop's IP address. Masks are constructed by setting
bits in sequence from the most-significant bit
downwards for ipRouteNextHopMask bits length. All other
bits in the mask, up to the number needed to fill the
length of the address ipRouteNextHop are cleared to
zero. A zero bit in the mask then means that the
corresponding bit in the address always matches."
::= { ipRouteEntry 7 }
ipRoutePhbId OBJECT-TYPE
SYNTAX Integer32 (-1 | 0..63)
STATUS current
DESCRIPTION
"The binary encoding that uniquely identifies a Per Hop
Behaviour (PHB, [16]) or a set of PHBs associated to
the DiffServ Code Point (DSCP) marking of the IP
datagrams that will be conveyed along this route. A
value of -1 indicates that a specific PHB ID value has
not been defined, and thus, all PHB ID values are
considered a match."
::= { ipRouteEntry 8 }
ipRouteOriginOBJECT-TYPE
SYNTAX INTEGER {
OSPF (0)
IS-IS (1)
BGP (2)
STATIC (3)
OTHER (4)
}
STATUS current
DESCRIPTION
"The value indicates the origin of the route. Either
the route has been computed by OSPF, by IS-IS,
announced by BGP4, is static, or else."
::= { ipRouteEntry 9 }
ipRouteIfIndex OBJECT-TYPE
SYNTAX Unsigned32 (0..65535)
STATUS current
DESCRIPTION
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"The ifIndex value that identifies the local interface
through which the next hop of this route is
accessible."
::= { ipRouteEntry 10 }
--
-- Route statistics classes. The information contained
-- in the yet-to-be defined tables aim at reporting statistics about
-- COPS control traffic, route traffic and potential errors. The
-- next version of the draft will provide a first table that will be
-- based upon the use of the "count" clause.
--
--
END
6. Security Considerations
The traffic engineering policy provisioning data as they are
described in this PIB will be used for configuring the appropriate
network elements that will be involved in the dynamic enforcement of
the corresponding routing and traffic engineering policies, by means
of a COPS-PR communication that will convey this information.
The function of dynamically provisioning network elements with such
configuration information implies that only an authorized COPS-PR
communication takes place.
From this perspective, this draft does not introduce any additional
security issues other than those that have been identified in the
COPS-PR specification, and it is therefore recommended that the IPSec
([17]) protocol suite be used to secure the above-mentioned
authorized communication.
7. References
[1] Bradner, S., "The Internet Standards Process -- Revision 3",
BCP 9, RFC 2026, October 1996.
[2] Boyle, J., Cohen, R., Durham, D., Herzog, S., Raja R., Sastry
A., "The COPS (Common Open Policy Service) Protocol", RFC 2748,
Proposed Standard, January 2000.
[3] Ho Chan, K., Durham, D., Gai, S., Herzog, S., McLoghrie, K.,
Reichmeyer, F., Seligson, J., Smith, A., Yavatkar, R., "COPS
Usage for Policy Provisioning (COPS-PR)", RFC 3084, March 2001.
[4] Katz, D., Yeung, D., Kompella, K., "Traffic Engineering
Extensions to OSPF", draft-katz-yeung-ospf-traffic-10.txt, Work
in Progress, June 2003.
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[5] Smit, H., Li, T., "IS-IS Extensions for Traffic Engineering",
draft-ietf-isis-traffic-04.txt, Work in Progress, December
2002.
[6] ISO/IEC 10589, "Intermediate System to Intermediate System,
Intra-Domain Routing Exchange Protocol for use in Conjunction
with the Protocol for Providing the Connectionless-mode Network
Service (ISO 8473)", June 1992.
[7] Jacquenet, C., "Providing Quality of Service Indication by the
BGP-4 Protocol: the QOS_NLRI Attribute", draft-jacquenet-qos-
nrli-05.txt, Work in Progress, June 2003.
[8] Moore, B. et al., "Policy Core Information Model -- Version 1
Specification", RFC 3060, February 2001.
[9] Jacquenet, C., "A COPS client-type for IP traffic engineering",
draft-jacquenet-ip-te-cops-04.txt, Work in Progress, January
2003.
[10] Sahita, R., et al., "Framework Policy Information Base", RFC
3318, March 2003.
[11] McLoghrie, K., et al., "Structure of Policy Provisioning
Information (SPPI)", RFC 3159, August 2001.
[12] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997
[13] Boucadair, M., "An IP TE PIB for Accounting purposes", draft-
boucadair-ipte-acct-pib-02.txt, Work in Progress, June 2003.
[14] Rosen, E., et al., "Multiprotocol Label Switching
Architecture", RFC 3031, January 2001.
[15] Daniele, M., Haberman, B., Routhier, S., Schoenwaelder, J.,
"Textual Conventions for Internet Network Addresses", RFC 3291,
May 2002.
[16] Black, D., Brim, S., Carpenter, B., Le Faucheur, F., "Per Hop
Behaviour Identification Codes", RFC 3140, June 2001.
[17] Kent, S., Atkinson, R., "Security Architecture for the Internet
Protocol", RFC 2401, November 1998.
8. Acknowledgments
Part of this work is funded by the European Commission, within the
context of the MESCAL (Management of End-to-End Quality of Service
Across the Internet At Large, http://www.mescal.org) project, which
is itself part of the IST (Information Society Technologies) research
program.
The authors would also like to thank all the partners of the MESCAL
project for the fruitful discussions that have been conducted so far
within the context of the traffic engineering specification effort of
the project.
9. Authors' Addresses
Mohamed Boucadair
France Telecom R & D
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DMI/SIR
42, rue des Coutures
BP 6243
14066 Caen Cedex 4
France
Phone: +33 2 31 75 92 31
Email: mohamed.boucadair@francetelecom.com
Christian Jacquenet
France Telecom Long Distance
3, avenue Franois Chteau
CS 36901
35069 Rennes CEDEX
France
Phone: +33 2 99 87 63 31
Email: christian.jacquenet@francetelecom.com
10. Full Copyright Statement
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