A Logic Programming Approach to Con ict Resolution in PolicyManagement

The simple event-condition-action (ECA) rule paradigm of active databases has proved very useful in many AI and database applications. However, its applicability goes beyond data management. ECA rules can be used in network management and monitoring , electronic commerce, security and access management, and other application areas to express policies { collections of general principles specifying the desired behavior of a system. In this paper we use a declarative policy description language PDL, in which policies are formulated as sets of ECA rules. The main contribution of the paper is a framework for detecting action connicts and nding resolutions to these connicts. Connicts are captured as violations of action constraints. The semantics of rules, and connict detection and resolution are deened axiomatically using logic programs. Given a policy and a set of action constraints the framework deenes a monitor that lters the output of the policy to satisfy the constraints. We brieey describe the architecture of a PDL-based policy server being used to provide centralized administration of a soft switch in a communication network and show how it can be augmented to handle connict resolution.