RFC 3483 (rfc3483) - Page 3 of 10
Framework for Policy Usage Feedback for Common Open Policy Service with Policy Provisioning (COPS-PR)
Alternative Format: Original Text Document
RFC 3483 COPS Feedback Framework March 2003 The scope of this document is to describe the framework for policy usage monitored and reported by the PEP and collected at the PDP. The charging, rating and billing models, as well as other accounting or statistics gathering events, detectable by the PDP are beyond the scope of this framework. 2 Overview There are three main aspects to define policies for usage feedback: - which objects are monitored - the metrics to be monitored and reported for these objects - when the reports are delivered In the framework, a selection criteria policy specifies one or more objects that should be monitored (e.g., a dropper or the instances of an IP Filter for all its interfaces). A usage feedback class is used to specify which metrics are to be collected for a set of objects - instances of the specified class carry the usage information when it is reported. The valid combinations of monitored object classes and usage 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 of 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 Per COPS [RFC 2748], the PDP specifies the minimum feedback 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 report messages. The purpose of this interval is to pace the number of report messages sent to the PDP. It is not the goal of the interval defined by the ACCT Timer value to provide precision synchronization or timing. The selection and the associated usage criteria and intervals for feedback reporting are defined by the PDP. Feedback policies, which define the necessary selection and linkages to usage feedback criteria, are included by the PDP in a Decision message to the PEP. The usage feedback is then periodically reported by the PEP, at intervals defined in the linkage policies at a rate no more frequently than specified in the Accounting Timer object. Note that Rawlins, et al. Informational
