draft-ietf-rap-feedback-frwk-01.txt   draft-ietf-rap-feedback-frwk-02.txt 
Internet Draft Diana Rawlins Internet Draft Diana Rawlins
Expiration: May 2002 WorldCom Expiration: September 2002 WorldCom
File: draft-ietf-rap-feedback-frwk-01.txt Amol Kulkarni File: draft-ietf-rap-feedback-frwk-02.txt Amol Kulkarni
Intel Intel
Martin Bokaemper
Unisphere Networks
Kwok Ho Chan
Nortel Networks
Framework of COPS-PR Policy Usage Feedback Framework of COPS-PR Policy Usage Feedback
Last Updated November 20, 2001 Last Updated March 1, 2002
Status of this Memo Status of this Memo
This document is an Internet-Draft and is in full conformance with This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026. all provisions of Section 10 of RFC2026.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet- other groups may also distribute working documents as Internet-
Drafts. Drafts.
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Conventions used in this document Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL
NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL"
in this document are to be interpreted as described in [RFC-2119]. in this document are to be interpreted as described in [RFC-2119].
Abstract Abstract
Common Open Policy Services Protocol [COPS], RFC 2748, defined the Common Open Policy Services Protocol [COPS], RFC 2748, defined the
capability of reporting information to the PDP. The types of capability of reporting information to the PDP. The types of
report information are success, failure and accounting of an report information are success, failure and accounting of an
installed state. This document focuses on the accounting report installed state. This document focuses on the COPS Report Type of
type and the necessary framework for the monitoring and reporting Accounting and the necessary framework for the monitoring and
of usage feedback for an installed state. reporting of usage feedback for an installed state.
Table of Contents Table of Contents
1 Introduction...................................................3 1 Introduction...................................................3
2 Overview.......................................................3 2 Overview.......................................................3
3 Requirements for Normal Operations.............................3 3 Requirements for Normal Operations.............................3
4 Periodic Nature of Policy Usage Feedback.......................4 4 Periodic Nature of Policy Usage Feedback.......................4
4.1 Reporting Intervals..........................................4 4.1 Reporting Intervals..........................................4
5 Suspension, Resumption and Halting of Usage Monitoring and 5 Suspension, Resumption and Halting of Usage Monitoring and
Reporting........................................................5 Reporting........................................................5
6 Solicited Feedback.............................................5 6 Solicited Feedback.............................................5
7 Usage reports on shared objects................................5 7 Usage reports on shared objects................................5
8 Context........................................................6 8 Context........................................................6
9 Delete Request States..........................................6 9 Delete Request States..........................................6
10 Failover......................................................6 10 Failover......................................................6
11 Security Considerations.......................................6 11 Security Considerations.......................................6
12 Authors' Addresses............................................6 12 Authors' Addresses............................................7
13 References....................................................7 13 References....................................................7
1 Introduction 1 Introduction
Policy usage reported by the PEP makes a richer set of information Policy usage reported by the PEP makes a richer set of information
available to the PDP for decision-making. This report accounting available to the PDP for decision-making. This feedback on policy
information can impact future decisions made by the PDP and the usage can impact future decisions made by the PDP and the
resulting policy installed by the PDP at the PEP. For example, a resulting policy installed by the PDP at the PEP. For example, a
PDP making policy for a SIP signaled multimedia session may need PDP making policy for a SIP signaled multimedia session may need
to base the decision in part on usage information related to to base the decision in part on usage information related to
previously installed QoS policy decisions. Furthermore, the PDP previously installed QoS policy decisions. Furthermore, the PDP
may coordinate this usage information with other external systems may coordinate this usage information with other external systems
to determine the future policy such as the case with the PDP to determine the future policy such as the case with the PDP
coordinating multimedia session QoS and clearinghouse coordinating multimedia session QoS and clearinghouse
authorizations [SIP-AAA-QOS.] authorizations [SIP-AAA-QOS.]
The scope of this document is to describe the framework for policy The scope of this document is to describe the framework for policy
usage monitored and reported by the PEP and collected at the PDP. usage monitored and reported by the PEP and collected at the PDP.
The charging, rating and billing models as well as other The charging, rating and billing models as well as other
accounting or statistics gathering events detectable by the PDP accounting or statistics gathering events detectable by the PDP
are beyond the scope of this framework. are beyond the scope of this framework.
2 Overview 2 Overview
There are two aspects to defining policies for usage feedback. One There are three main aspects to define policies for usage
aspect is defining what to monitor and the second is defining what feedback:
to report. The selection criteria policy specifies the conditions - which objects are monitored
for the monitoring and recording of the associated usage policy. - the metrics to be monitored and reported for these objects
It is a PRID that defines an entity such as an IP filter or - when the reports are delivered
dropper. The usage criteria policy class defines what metrics are
recorded and reported by the PEP to the PDP in the Report message. In the framework a selection criteria policy specifies one or more
For example, a usage policy may be defined to provide counts of objects that should be monitored ű for example a dropper or the
packets received. The selection criteria policy may identify the instances of an IP Filter for all its interfaces.
filter on which to base the packet counts. A third policy may be
used to associated, or link, the selection and usage policies. The A usage feedback class is used to specify which metrics are to be
linkage criteria associate what needs to be monitored to what collected for a set of objects - instances of the specified class
needs to be reported. The valid combinations of selection PRCs for carry the usage information when it is reported.
a usage PRC must be identified and well understood between the PDP The valid combinations of monitored object classes and usage
and the PEP. feedback classes are reported by the PEP as capabilities.
Finally selection criteria policy and usage feedback class are
bound together in a linkage policy, which also contains the
information when reports are generated. Reports are usually sent
periodically but more restrictions can be placed on the generation
of reports, like thresholds or a change in the data.
3 Requirements for Normal Operations 3 Requirements for Normal Operations
Per [COPS], the PDP specifies the minimum feedback interval in the Per [COPS], the PDP specifies the minimum feedback interval in the
Accounting Timer object that is included in the Client Accept Accounting Timer object that is included in the Client Accept
message during connection establishment. This specifies the message during connection establishment. This specifies the
maximum frequency with which the PEP issues unsolicited accounting maximum frequency with which the PEP issues unsolicited accounting
type reports. The purpose of this interval is to pace the number type report messages. The purpose of this interval is to pace the
of report messages sent to the PDP. It is not the goal of the number of report messages sent to the PDP. It is not the goal of
interval defined by the ACCT Timer value to provide precision the interval defined by the ACCT Timer value to provide precision
synchronization or timing. synchronization or timing.
The selection and usage criteria for feedback reporting are The selection and the associated usage criteria and intervals for
defined by the PDP. Feedback policies, which define the necessary feedback reporting are defined by the PDP. Feedback policies,
selection and usage criteria, are included by the PDP in a which define the necessary selection and linkages to usage
Decision message to the PEP. The usage is then periodically feedback criteria, are included by the PDP in a Decision message
reported by the PEP at intervals no more frequently than specified to the PEP. The usage feedback is then periodically reported by
in the Accounting Timer object, except as noted in the following the PEP at intervals defined in the linkage policies at a rate no
sections. (There are exceptions where reports containing feedback more frequently than specified in the Accounting Timer object.
are provided prior the interval in several cases described in Note that there are exceptions where reports containing feedback
sections 6 and 7.) The PDP may also solicit usage feedback which are provided prior the Accounting Timer interval in several cases
is to be reported back immediately by the PEP. Usage information described in sections 6 and 7.) The PDP may also solicit usage
may be cleared upon reporting. This is specified in the usage feedback which is to be reported back immediately by the PEP.
policy criteria. Usage information may be cleared upon reporting. This is
specified in the usage policy criteria.
The PEP monitors and tracks the usage information. The PDP is the The PEP monitors and tracks the usage feedback information. The
collection point for the policy usage information reported by the PDP is the collection point for the policy usage feedback
PEP clients within the administrative domain. The PDP may also information reported by the PEP clients within the administrative
collect other accounting event information that is outside the domain. The PDP may also collect other accounting event
scope of this document. information that is outside the scope of this document.
4 Periodic Nature of Policy Usage Feedback 4 Periodic Nature of Policy Usage Feedback
Generally the accounting policy is periodic in nature and the Generally the policy usage feedback is periodic in nature and the
reporting is unsolicited. The unsolicited reports are supplied per reporting is unsolicited. The unsolicited reports are supplied per
the interval defined by the PDP. The periodic unsolicited reports the interval defined by the PDP. The periodic unsolicited reports
are dictated by timer intervals and use a deterministic amount of are dictated by timer intervals and use a deterministic amount of
network resources. network resources.
The PDP informs the PEP of the minimal feedback interval during The PDP informs the PEP of the minimal feedback interval during
client connection establishment with the Accounting Timer object. client connection establishment with the Accounting Timer object.
The PDP may specify feedback intervals in the specific usage The PDP may specify feedback intervals in the specific usage
policies as well. The unsolicited monitoring and reporting by the feedback policies as well. The unsolicited monitoring and
PEP may be suspended and resumed at the direction of the PDP. reporting by the PEP may be suspended and resumed at the direction
of the PDP.
4.1 Reporting Intervals 4.1 Reporting Intervals
The generation of usage feedback by the PEP to the PDP is done The generation of usage feedback by the PEP to the PDP is done
under different conditions that include feedback on demand, under different conditions that include feedback on demand,
periodic feedback or feedback when a defined threshold is reached. periodic feedback or feedback when a defined threshold is reached.
The periodic feedback for a usage policy can be further defined in The periodic feedback for a usage policy can be further defined in
terms of providing feedback if there is a change or providing terms of providing feedback if there is a change or providing
feedback periodically regardless of a change in value. feedback periodically regardless of a change in value.
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The PDP may direct the PEP to suspend usage feedback report The PDP may direct the PEP to suspend usage feedback report
messages and then at a later time instruct the PEP to resume the messages and then at a later time instruct the PEP to resume the
reporting of feedback. The PDP may also instruct the PEP to reporting of feedback. The PDP may also instruct the PEP to
suspend the monitoring and tracking of usage which also results in suspend the monitoring and tracking of usage which also results in
the suppression of the feedback reports until the PDP later tells the suppression of the feedback reports until the PDP later tells
the PEP to resume the monitoring (and reporting). When the PDP the PEP to resume the monitoring (and reporting). When the PDP
suspends monitoring or suspends reporting, it also specifies suspends monitoring or suspends reporting, it also specifies
whether the PEP is to provide an unsolicited feedback report of whether the PEP is to provide an unsolicited feedback report of
the current monitored usage of the affected usage policy. The PDP the current monitored usage of the affected usage policy. The PDP
may suspend and resume monitoring and reporting for specific usage may suspend and resume monitoring and reporting for specific usage
policies or for all usage policies. policies or for all of the usage feedback policies.
Halting of usage monitoring and feedback is done by issuing a
Decision Remove of the feedback usage policies. The PEP is to stop
any monitoring and reporting associated with the policy
immediately.
6 Solicited Feedback 6 Solicited Feedback
There may be instances when it is useful for the PDP to control There may be instances when it is useful for the PDP to control
the feedback per an on-demand basis rather than a periodic basis. the feedback per an on-demand basis rather than a periodic basis.
The PDP may solicit the PEP for usage feedback with a Decision. The PDP may solicit the PEP for usage feedback with a Decision.
The PDP may solicit usage feedback at any time during the The PDP may solicit usage feedback at any time during the
accounting interval defined by the ACCT Timer. The PEP responds accounting interval defined by the ACCT Timer. The PEP responds
immediately and reports the appropriate usage policies and should immediately and reports the appropriate usage policies and should
continue to follow the usage feedback interval schedule continue to follow the usage feedback interval schedule
established during connection acceptance. established during connection acceptance.
7 Usage reports on shared objects 7 Usage reports on shared objects
While some objects in a contextĺs namespace directly represent While some objects in a contextĂs namespace directly represent
unique objects of the PEPĺs configuration, other COPS objects can unique objects of the PEPĂs configuration, other COPS objects can
be shared between multiple actual assignments in the PEP. be shared between multiple actual assignments in the PEP.
Whenever the PEP creates multiple actual configuration instances Whenever the PEP creates multiple actual configuration instances
from the same COPS objects, these assignments can potentially from the same COPS objects, these assignments can potentially
collect their own statistics independently. Since the individual collect their own statistics independently. Since the individual
assignments do not have a direct representation as COPS objects, assignments do not have a direct representation as COPS objects,
additional information must be provided to uniquely identify the additional information must be provided to uniquely identify the
assignment that generates the usage information. assignment that generates the usage information.
The feedback framework allows this information to be distributed The feedback framework allows this information to be distributed
between a Selection Criteria PRC and the corresponding Usage PRC, between a selection criteria PRC and the corresponding usage
however both PRCs together always must contain sufficient feedback PRC, however both PRCs together always must contain
information for the finest granularity of usage collection sufficient information for the finest granularity of usage
supported by the PEP. collection supported by the PEP.
If all the additional information is not part of the Selection If all the additional information is not part of the selection
Criteria PRC, all matching assignments are selected to collect criteria PRC, all matching assignments are selected to collect
usage information. The necessary data to differentiate these usage information. The necessary data to differentiate these
assignments is part of the Usage PRC. assignments is part of the usage feedback PRC.
Implementations based on the feedback framework should always Implementations based on the feedback framework should always
provide a Selection Criteria PRC that contains a complete set of provide a selection criteria PRC that contains a complete set of
information to select a unique assignment, while underspecified information to select a unique assignment, while underspecified
Selection Criteria PRCs (together with extended Usage PRCs) are selection criteria PRCs (together with extended usage feedback
optional. PRCs) are optional.
8 Context 8 Context
The monitoring and recording of usage policies is subject to The monitoring and recording of usage policies is subject to
context switches in a manner similar to that of the enforcement context switches in a manner similar to that of the enforcement
policy. Usage policy is monitored, recorded and reported while the policy. Usage policy is monitored, recorded and reported while the
associated policy information context is active. When the context associated policy information context is active. When the context
is deactivated a report containing the usage policies for that is deactivated a report message containing the usage feedback
context is provided to the PDP. The PEP does not perform any policies for that context is provided to the PDP. The PEP does not
monitoring, tracking or reporting of policy usage for a given perform any monitoring, tracking or reporting of policy usage for
context while the context is inactive. a given context while the context is inactive.
9 Delete Request States 9 Delete Request States
The PEP MUST send any outstanding usage data monitored during the The PEP MUST send any outstanding usage feedback data monitored
feedback interval to the PDP via an unsolicited report immediately during the feedback interval to the PDP via an unsolicited report
prior to issuing a Delete Request State. This is also the case message immediately prior to issuing a Delete Request State. This
when the PDP initiates the Delete Request State. is also the case when the PDP initiates the Delete Request State.
10 Failover 10 Failover
In the event the connection is lost between the PEP and PDP, the In the event the connection is lost between the PEP and PDP, the
PEP continues to track usage information as long as it continues PEP continues to track usage feedback information as long as it
to enforce installed (cached) policy. When the locally installed continues to enforce installed (cached) policy. When the locally
policy at the PEP expires, the usage policy data also expires and installed policy at the PEP expires, the usage feedback policy
is no longer monitored. data also expires and is no longer monitored.
Upon successful reconnection where the PEP is still caching Upon successful reconnection where the PEP is still caching
policy, the PDP indicates deterministically to the PEP that the policy, the PDP indicates deterministically to the PEP that the
PEP may resume usage feedback reporting. The PEP reports all PEP may resume usage feedback reporting. The PEP reports all
cached usage and resumes periodic reporting making any needed cached usage and resumes periodic reporting making any needed
adjustment to the interval schedule as specified in the adjustment to the interval schedule as specified in the
reconnection acceptance ACCT Timer. reconnection acceptance ACCT Timer.
11 Security Considerations 11 Security Considerations
The feedback information is sensitive and requires that authorized The feedback information is sensitive and requires that authorized
messaging occur between the PEP and the PDP. This protection can messaging occur between the PEP and the PDP. This protection can
be accomplished with IPSEC between the PEP and the PDP or using be accomplished with IPSEC between the PEP and the PDP, TLS [COPS
the security mechanisms described in the base COPS protocol. TLS] or using the security mechanisms described in the base COPS
protocol.
12 Authors' Addresses 12 Authors' Addresses
Diana Rawlins Diana Rawlins
WorldCom WorldCom
901 International Parkway 901 International Parkway
Richardson, Texas 75081 Richardson, Texas 75081
Phone: 972-729-1044 Phone: 972-729-1044
Email: Diana.Rawlins@wcom.com Email: Diana.Rawlins@wcom.com
Amol Kulkarni Amol Kulkarni
JF3-206 JF3-206
2111 NE 25th Ave 2111 NE 25th Ave
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Phone: 972-729-1044 Phone: 972-729-1044
Email: Diana.Rawlins@wcom.com Email: Diana.Rawlins@wcom.com
Amol Kulkarni Amol Kulkarni
JF3-206 JF3-206
2111 NE 25th Ave 2111 NE 25th Ave
Hillsboro, Oregon 97124 Hillsboro, Oregon 97124
Phone: 503-712-1168 Phone: 503-712-1168
Email: amol.kulkarni@intel.com 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
Martin Bokaemper
Unisphere Networks
700 Silver Seven Road
Kanata, ON, K2V 1C3, Canada
Phone: 613-591-2735
Email: mbokaemper@unispherenetworks.com"
13 References 13 References
[COPS] Boyle, J., Cohen, R., Durham, D., Herzog, S., Rajan, R., [COPS] Boyle, J., Cohen, R., Durham, D., Herzog, S., Rajan, R.,
and A. Sastry, "The COPS (Common Open Policy Service) Protocol" and A. Sastry, "The COPS (Common Open Policy Service) Protocol"
RFC 2748, January 2000. RFC 2748, January 2000.
[SIP-AAA-QOS] Gross, G., Sinnreich, H. Rawlins D., Havinis, T. "QoS [SIP-AAA-QOS] Gross, G., Sinnreich, H. Rawlins D., Havinis, T. "QoS
and AAA Usage with SIP Based IP Communications" draft-gross-sipaq- and AAA Usage with SIP Based IP Communications" draft-gross-sipaq-
00.txt, November 2000. 00.txt, November 2000.
[COPS-TLS], Walker, J., Kulkarni, A.,÷COPS Over TLS÷, draft-ietf-
rap-cops-tls-02.txt, October 2001.
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