Internet Draft Diana Rawlins
Expiration: March 2001 WorldCom
File: draft-ietf-rap-acct-fr-pib-01.txt Amol Kulkarni
Intel
Kwok Ho Chan
Nortel Networks
Dinesh Dutt
Cisco
Framework of COPS-PR Policy Information Base for Accounting Usage
Last Updated March 2 2001
Status of this Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026.
Internet-Drafts are working documents of the Internet Engineering
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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].
Abstract
Currently there are no policy classes defined for the PEP to convey
provisioned policy usage feedback to the PDP. The purpose of this
document is to define the accounting framework PIB that specifies the
policy classes common for COPS accounting type reports. The basic
operation and objects for reporting usage information are defined in
[COPS]. A specific clientSI accounting type object named REPORT is
defined in [COPS-PR]. This document further describes operational
behavior that is implied in [COPS] and [COPS-PR.]
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Table Of Contents
1 Introduction.....................................................3
2 General Concepts.................................................3
2.1 Overview.......................................................3
2.2 Normal Operation...............................................3
2.3 Failover.......................................................4
2.4 Context........................................................4
2.5 Delete Request States..........................................4
2.6 Periodic nature of report accounting...........................4
3 Definition of Accounting Type Report Policy......................5
4 Summary of the Accounting Framework Policy Information Base......6
4.1 SPPI ACCESS clause report-only.................................6
4.2 Textual Conventions Counts.....................................6
4.3 Accounting Type Report Group and PRCs..........................6
4.3.1 The Accounting Type Report Resume Table......................7
4.3.2 The Accounting Type Report Linkage Table.....................7
4.3.3 The Filter Usage Table.......................................7
5 The Accounting Framework PIB Module..............................7
6 Security Considerations.........................................13
7 Acknowledgements................................................13
8 Authors' Addresses..............................................13
9 References......................................................13
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1 Introduction
Policy usage reported by the PEP makes a richer set of information
available to the PDP for decision-making. This report accounting
information can influence future decisions made by the PDP and the
resulting policy installed by the PDP at the PEP. For example, A PDP
determining policy for a SIP signaled multimedia session may need to
base the decision in part on usage information related to previously
installed QoS policy decisions. Further, the PDP may coordinate this
usage information with other external systems to determine the future
policy such as the case with the PDP coordinating multimedia session
QoS and clearinghouse authorizations [SIP-AAA-QOS]
The scope of this document is to describe the policy class framework
for policy usage monitored and reported by the PEP and collected at
the PDP. The charging and billing models as well as other accounting
events detectable by the PDP are beyond the scope of this framework.
2 General Concepts
2.1 Overview
There are two aspects to defining policies for an accounting type
report the selection aspect and the policy usage aspect. The
usage policy and selection policy are associated with one another.
The usage criteria policy class defines what metrics are monitored,
recorded and reported by the PEP. The selection criteria policy class
specifies the conditions for the monitoring and recording of the
associated usage policy. For example, a usage policy may be defined
to provide counts of packets received. The selection criteria policy
may identify the filter on which to base the packet counts. A third
policy may be used to associate, or link, the selection and usage
policies. The linking is performed by the accounting type report
linkage policy.
2.2 Normal Operation
The PDP specifies the minimum accounting interval in the Accounting
Timer object that is included in the Client Accept message during
connection establishment. This specifies the maximum frequency with
which the PEP issues unsolicited accounting type reports. The PEP
notifies the PDP of the selection criteria policy classes and usage
policy classes it supports during the initial request for
configuration data using the frwkPRCSupportTable entries[FR-PIB].
The PDP responds to the initial request for configuration with a
DECISION that installs policies. The PDP may also specify maximum
reporting intervals associated with each of the policies. The PEP
monitors and records the usage per the selection criteria defined by
the PDP. Periodically the PEP reports the usage with an accounting
type REPORT.
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The PDP is the collection point for the usage information monitored
and reported by the PEP clients within the administrative domain. The
PDP may also collect other accounting event information that is
outside the scope of this document.
2.3 Failover
In the event the connection is lost between the PEP and PDP, the PEP
continues to track usage information as long as it continues to
operate with the installed policy. When the locally installed policy
at the PEP expires, the usage policy data also expires.
Upon successful reconnection where the PEP is still caching policy,
the PDP indicates to the PEP that the PEP may resume sending of the
accounting type report messages. The PDP does this deterministically.
It issues an unsolicited decision containing the
frwkAtRptResumeIndicator set to resume reporting. The PDP is aware of
the request state Handle(s) and the supported PRCs either through the
state synchronization mechanism or because the PDP considers itself
synchronized with the PEP upon reconnection.
2.4 Context
The monitoring and recording of usage policies is subject to context
switches in a manner similar to enforcement policy. The usage policy
is monitored, recorded and reported while the associated PIB instance
is active. The PEP should retain existing accounting data during
inactive contexts and resume it's monitoring and reporting when the
PIB instance becomes active again.
2.5 Delete Request States
The PEP may send any outstanding accounting data monitored during the
interval to the PDP via an unsolicited report immediately prior to
issuing a Delete Request State if the time interval since the last
report is not less than the interval defined by the Accounting Timer.
This is also the case when the PDP initiates the Delete Request State
with a decision request delete state. In this case where a PDP
initiates a Decision Request State Remove, the PEP acknowledges with
the Report, but the actual Delete Request State may be delayed until
the next reporting interval has completed.
2.6 Periodic nature of report accounting
The PDP informs the PEP of the minimal accounting interval it
supports in the Accounting Timer object during client connection
establishment. The PDP may specify accounting intervals in the
specific accounting policies per the PEP's indicated capabilities.
The PDP may also halt reporting for a request state by issuing an
unsolicited decision with the frwkAtRptResumeIndicator set to halt
reporting. Any usage information associated with that request state
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at the PEP since the last accounting interval is discarded by the
PEP.
Generally the accounting policy is periodic in nature and the
reporting is unsolicited. The unsolicited reports are supplied within
the interval decided by the PDP. Note that periodic unsolicited
reports (as dictated by timer intervals) use a deterministic amount
of network resources.
There may be instances where the nature of the accounting policy for
a given client type or accounting PIB module is such that it is
useful for the PDP to control when it receives the feedback. The PDP
may therefore have the capability to solicit the accounting report
for a request state.
3 Definition of Accounting Type Report Policy
There are three basic types of policy used to define what the PEP is
to monitor, record and report. These are the selection criteria
policy, the usage policy and the accounting type report linkage
policy.
The selection criteria policy is installed by the PDP. It defines the
conditions used by the PEP to monitor and record a usage policy.
Generally, the selection criterion is an existing PRC such as the
frwkIPFilterTable. This PRC is useful for specifying conditions on
which to base usage - i.e. count the number of packets received for
this filter. The filter (source address, destination address, etc.)
in this case defines the conditions. In the case of the accounting
framework PIB, the frwkIPFilterTable is the only PRC used to base
selection on.
The usage policy defines what attributes are monitored and recorded
by the PEP. These policies have an ACCESS clause of Report.
Generally, the usage policies specify counts related to a specific
action such as a packet being dropped. The accounting framework PIB
defines one usage policy class, frwkAtRptFilterStats. It counts
packets and bytes as well as records the timestamp when the last
packet was received. Usage PRCs may be generic, collecting basic
statistics, or they may be specific to a particular usage. The PDP
decides which PRC(s) best suit(s) its requirements. The PEP may
support only one usage PRC, in which case all statistics are gathered
using instances of that PRC. Alternatively, the PEP may support
multiple usage PRCs. The PDP then decides which PRC to associate with
a particular selection criterion.
The accounting type report linkage permits the same selection
criteria instance to be re-used for various usage policies. For
example, the same IP Filter selection criteria could be the basis of
different usage policies such as packet count, drop count, and remark
count. The accounting type report linkage references the selection
criteria instance as well as defines the policy class of the usage
PRC. As noted above, the selection criteria policy may be used for
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enforcement policies as well as usage policies. This is the case with
the frwkIPFilterTable.
----------------- ------------------ -----------------
| | | | | |
| Select Criteria | |Linkage Instance | |Usage Instance |
| | |-instance ID | |- instance ID |
| -instance ID |<--|-PRID of selection|--->|- PRID of Linkage|
| -conditions... | |-PRC of usage | |- counts... |
| | | | | |
----------------- ------------------ -----------------
Figure 1
Figure 1 illustrates the relationship between a selection criteria,
linkage and usage policies.
The PDP is not aware of the instance identifier of the usage policy
when installing the selection criteria and accounting type report
linkage policies. The usage policy is enabled on the PEP by the
installation of an accounting type report linkage and the PEP
designates the instance identifier. The usage policy class always
contains an attribute of type Prid. This attribute contains the value
of the accounting type report linkage PRID [COPS-PR] installed by the
PDP that is associated with the usage policy. Note that the Prid type
is a textual convention for an object identifier that is the PRC of
the table used for the selection criteria and where the last sub-
identifier is an instance ID of the accounting type report linkage.
4 Summary of the Accounting Framework Policy Information Base
4.1 SPPI ACCESS clause report-only
The selection criteria and linkage policy classes follow the
definitions specified by [SPPI.] This structure specifies well-
defined policy classes and their instances residing in a common,
virtual repository [FR-PIB.] The additional PIB-ACCESS clause
attribute of "report-only" denotes the usage policy class reported by
the PEP.
4.2 Textual Conventions Counts
The usage policy attributes are often defined in the terms of counts.
This type is a non-negative value that is incremented. This value is
to "stick" at the maximum value if the maximum value is reached
before the reporting interval. It is reset to the value zero after
the usage is reported to the PDP and continues the incremental
operation. A textual convention defining the counts is defined in the
Accounting Framework PIB.
4.3 Accounting Type Report Group and PRCs
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It is useful to define reporting intervals and restart
characteristics as well as the common usage and selection criteria
polices. These policy classes are common to account type reporting
for various technologies and apply to ALL SUBJECT-CATEGORIES. The
policy classes belong to a new group, Accounting Type Report Group.
The policy classes in the Accounting Type Report Group are:
1) Accounting Type Report Device Intervals Table
2) Accounting Type Report Linkage Table
3) Accounting Type Filter Statistics Usage Table
4.3.1 The Accounting Type Report Resume Table
This table contains one row. It indicates that the PDP, to which a
PEP having cached usage policy has reconnected, is ready to receive
the accounting type report messages from the PEP.
4.3.2 The Accounting Type Report Linkage Table
This table links the selection criteria instance with the usage
instance. It specifies the PRID of the selection criteria and the PRC
of the usage instance. This table permits the reuse of a selection
criteria instance for multiple usage policies.
The linkage table also permits the definition of a maximum reporting
interval to use when issuing the accounting type reports for the
usage instance. This interval is defined in units of the Accounting
Timer Interval specified in the client accept message.
4.3.3 The Filter Usage Table
This table describes the packet counts, byte counts, last timestamp
when a packet was received and the PRID of the associated Accounting
Type Report Linkage instance. The count and timestamp information is
monitored and recorded by the PEP and supplied to the PDP with the
accounting type report message within the maximum interval specified.
5 The Accounting Framework PIB Module
ACCOUNTING-FRAMEWORK-PIB PIB-DEFINITIONS ::= BEGIN
IMPORTS
ExtUTCTime, Unsigned32, Unsigned64,
Integer32, MODULE-IDENTITY, OBJECT-TYPE
FROM COPS-PR-SPPI
TruthValue, TEXTUAL-CONVENTION
FROM SNMPv2-TC
PolicyInstanceId, PolicyReferenceId
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FROM COPS-PR-SPPI-TC;
RoleCombination
FROM POLICY-DEVICE-AUX-MIB;
acctPolFrameworkPib MODULE-IDENTITY
SUBJECT-CATEGORIES { all }
LAST-UPDATED "200011171000Z"
ORGANIZATION "IETF RAP WG"
CONTACT-INFO "
Diana Rawlins
WorldCom
901 International Parkway
Richardson, TX 75081
Phone: 972 729 1044
Email: diana.rawlins@wcom.com
Amol Kulkarni
JF3-206
2111 NE 25th Ave
Hillsboro, Oregon 97124
Phone: 503-712-1168
Email: amol.kulkarni@intel.com
Kwok Ho Chan
Nortel Networks, Inc.
600 Technology Park Drive
Billerica, MA 01821 USA
Phone: 978-288-8175
Email: khchan@nortelnetworks.com "
DESCRIPTION
"The PIB module containing the base set of policy rule
classes that are required for support of all accounting
and reporting policies"
::= { tbd }
--
-- The accounting type report group
--
frwkAtRptGroupClasses
OBJECT IDENTIFIER ::= { acctPolFrameworkPib 2 }
--
-- Textual Conventions
--
Count ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"A count represents a value used by attributes that
record policy usage. A count is of value zero or
greater and is incremented according to defined
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policy usage. When the maximum value is reached, the
value sticks. The value is reset to zero upon
reporting the value to the PDP."
SYNTAX Unsigned64 ( 0..18446744073709551615)
--
-- resume reporting indicator
--
frwkAtRptResumeTable OBJECT-TYPE
SYNTAX SEQUENCE OF FrwkAtRptResumeEntry
PIB-ACCESS install
STATUS current
DESCRIPTION
"This class contains a single PRI that indicates
that the PEP is to resume the sending of
accounting type reports."
::= { frwkAtRptGroupClasses 1}
frwkAtRptResumeEntry OBJECT-TYPE
SYNTAX FrwkAtRptResumeEntry
STATUS current
DESCRIPTION
"An instance of this class can indicate when to
resume sending accounting type reports
by the PEP."
PIB-INDEX { frwkAtRptResumeId}
::= { frwkAtRptResumeTable 1}
FrwkAtRptResumeEntry ::= SEQUENCE {
frwkAtRptResumeId InstanceId,
frwkAtRptResumeIndicator INTEGER
}
frwkAtRptResumeId OBJECT-TYPE
SYNTAX InstanceID
STATUS current
DESCRIPTION
" An arbitrary integer index that uniquely identifies an
instance of the frwkAtRptResumeTable class."
::= { frwkAtRptResumeEntry 1}
frwkAtRptResumeIndicator OBJECT-TYPE
SYNTAX INTEGER {
NO_REPORTS(0),
SEND_REPORTS(1)
}
STATUS current
DESCRIPTION
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"The value indicates if the PEP is to send cached
usage policies via accounting type report messages.
The enumeration values are:
(0) DonËt send accounting type report messages
(1) Resume accounting type report messages. Send
cached usage policies now "
::= { frwkAtRptResumeEntry 2 }
--
-- The Accounting Type Report Linkage Table
--
frwkAtRptLinkTable OBJECT-TYPE
SYNTAX SEQUENCE OF FrwkAtRptLinkEntry
PIB-ACCESS notify
STATUS current
DESCRIPTION
"This class associates the selection criteria with the
usage policy. It also permit the defining of the max
interval used for reporting the usage instance."
::= { frwkAtRptGroupClasses 2}
frwkAtRptLinkEntry OBJECT-TYPE
SYNTAX FrwkAtRptLinkEntry
STATUS current
DESCRIPTION
"This class associates the selection criteria with the
usage policy. It also permit the defining of the max
interval used for reporting the usage instance."
PIB-INDEX {frwkAtRptLinkId}
UNIQUENESS { frwkAtRptLinkId,
frwkAtRptLinkSel,
frwkAtRptLinkUsage }
::= {frwkAtRptLinkTable 1}
FrwkAtRptLinkEntry ::= SEQUENCE {
frwkAtRptLinkId InstanceID,
frwkAtRptLinkSel Prid,
frwkAtRptLinkUsage OBJECT IDENTIFIER,
frwkAtRptLinkInterval Integer32
}
frwkAtRptLinkId OBJECT-TYPE
SYNTAX InstanceID
STATUS current
DESCRIPTION
" An arbitrary integer index that uniquely identifies an
instance of the frwkAtRptLinkTable class."
::= { frwkAtRptLinkEntry 1}
frwkAtRptLinkSel OBJECT-TYPE
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SYNTAX Prid
STATUS current
DESCRIPTION
"The PRID of the selection criteria instance that
defines the conditions to use by the PEP for
monitoring the usage."
::= { frwkAtRptLinkEntry 2}
frwkAtRptLinkUsage OBJECT-TYPE
SYNTAX OBJECT IDENTIFIER
STATUS current
DESCRIPTION
"The PRC of the usage policy class that the PEP uses to
monitor,record and report."
::= { frwkAtRptLinkEntry 3}
frwkAtRptInterval OBJECT-TYPE
SYNTAX Integer32
STATUS current
DESCRIPTION
"Maximum interval in units of the value of the
Accounting Timer specificed by the PDP in the client
accept message. A frwkAtRptInterval of 1 is equal to
the value of the Accounting Timer. This value must be 1
or greater. "
::= { frwkAtRptLinkEntry 4}
--
-- The filter statistics usage
--
frwkAtRptFilterStatsUsageTable OBJECT-TYPE
SYNTAX SEQUENCE OF FrwkAtRptFilterStatsUsageEntry
PIB-ACCESS report-only
STATUS current
DESCRIPTION
"This class defines the usage attributes that the PEP
is to monitor, record and report. It contains the
of the PRID of the linkage instance associating
the selection criteria instance with the usage
instance."
::= { frwkAtRptGroupClasses 3}
frwkAtRptFilterStatsUsageEntry OBJECT-TYPE
SYNTAX FrwkAtRptFilterStatsUsageEntry
STATUS current
DESCRIPTION
"Defines the attributes the PEP is to monitor,
record and report."
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PIB-INDEX {frwkAtRptFilterStatsUsageId}
UNIQUENESS { frwkAtRptFilterStatsUsageLinkPRID }
::= {frwkAtRptFilterStatsUsageTable 1}
FrwkAtRptFilterStatsUsageEntry ::= SEQUENCE {
frwkAtRptFilterStatsUsageId InstanceID,
frwkAtRptFilterStatsUsageLinkPRID Prid,
frwkAtRptFilterStatsUsagePacketCount Counts,
frwkAtRptFilterStatsUsageByteCount Counts,
fwkAtRptFilterStatsUsageTimeStamp ExtUTCTime
}
frwkAtRptFilterStatsUsageId OBJECT-TYPE
SYNTAX InstanceId
STATUS current
DESCRIPTION
"Arbitrary integer index that uniquely identifies
an instance of the class."
::= { frwkAtRptFilterStatsUsageEntry 1 }
frwkAtRptFilterStatsUsageLinkPRID OBJECT-TYPE
SYNTAX Prid
STATUS current
DESCRIPTION
"The PRID of the Linkage policy instance used to base
this usage policy instance upon."
::= { frwkAtRptFilterStatsUsageEntry 2 }
frwkAtRptFilterStatsUsagePacketCount OBJECT-TYPE
SYNTAX Unsigned32
STATUS current
DESCRIPTION
"The count of packets matching the specified filter
during the reporting interval."
::= {frwkAtRptFilterStatsUsageEntry 3}
frwkAtRptFilterStatsUsageByteCount OBJECT-TYPE
SYNTAX Unsigned64
STATUS current
DESCRIPTION
"The byte count of packets matching the
specified filter during the reporting interval."
::= { frwkAtRptFilterStatsUsageEntry 4}
frwkAtRptFilterStatsSelectTimeStamp OBJECT-TYPE
SYNTAX ExtUTCTime
STATUS current
DESCRIPTION
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"The last timestamp when a packet was received."
::= { frwkAtRptFilterStatsSelectEntry 5}
END
6 Security Considerations
The accounting information is sensitive and requires that
authorized messaging occur between the PEP and the PDP. This
protection can be accomplished with IPSEC between the PEP and the
PDP or using the security mechanisms described in the base COPS
protocol.
7 Acknowledgements
The authors would like to thank Dave Durham and Russell Fenger of
Intel and John K. Gallant of WorldCom for their contribution to
this document.
8 Authors' Addresses
Diana Rawlins
WorldCom
901 International Parkway
Richardson, Texas 75081
Phone: 972-729-1044
Email: Diana.Rawlins@wcom.com
Amol Kulkarni
JF3-206
2111 NE 25th Ave
Hillsboro, Oregon 97124
Phone: 503-712-1168
Email: amol.kulkarni@intel.com
Kwok Ho Chan
Nortel Networks, Inc.
600 Technology Park Drive
Billerica, MA 01821 USA
Phone: 978-288-8175
Email: khchan@nortelnetworks.com
Dinesh G Dutt
Cisco Systems, Inc.
170 Tasman Dr.
San Jose, CA 95134-1706
Phone: 408-527-0955
Email: ddutt@cisco.com
9 References
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[COPS] Boyle, J., Cohen, R., Durham, D., Herzog, S., Rajan, R.,
and A. Sastry, "The COPS (Common Open Policy Service) Protocol"
RFC 2748, January 2000.
[COPS-PR] K. Chan, D. Durham, S. Gai, S. Herzog, K. McCloghrie, F.
Reichmeyer, J. Seligson, A. Smith, R. Yavatkar, "COPS Usage for
Policy Provisioning," draft-ietf-rap-cops-pr-05.txt, March 2000.
[SPPI] K. McCloghrie, et.al., "Structure of Policy Provisioning
Information," draft-ietf-rap-sppi-05.txt, February 2001.
[FR-PIB] M. Fine, K. McCloghrie, J. Seligson, K. Chan, S. Hahn, A.
Smith, F. Reichmeyer "Framework Policy Information Base", draft-
ietf-rap-frameworkpib-03.txt, November 2000
[DSPIB] M. Fine, K. McCloghrie, J. Seligson, K. Chan, S. Han, A.
Smith, F. Reichmeyer, "Differentiated Services Quality of Service
Policy Information Base", draft-ietf-diffserv-pib-02.txt, November
2000
[SIP-AAA-QOS] Gross, G.,Sinnreich, H. Rawlins D., Havinis, T. " QoS
and AAA Usage with SIP Based IP Communications" draft-gross-sipaq-
00.txt, November 2000.
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