A Logic Programming Approach to Conflict Resolution in Policy Management

The simple event- condition- action (ECA) rule paradigm of active databases has proved very useful in many AI and database appli cations. However, its applicability goes be yond data management. ECA rules can be used in network management and monitor ing, electronic commerce, security and access management, and other application areas to express policies - collections of general princi ples specifying the desired behavior of a sys tem. In this paper we use a declarative policy description language VDC, in which policies are formulated as sets of ECA rules. The main contribution of the paper is a frame work for detecting action conflicts and finding resolutions to these conflicts. Conflicts are captured as violations of action constraints. The semantics of rules, and conflict detection and resolution are defined axiomatically us ing logic programs. Given a policy and a set of action constraints the framework defines a monitor that filters the output of the policy to satisfy the constraints. We briefly describe the architecture of a VDC-based policy server being used to provide centralized administra tion of a soft switch in a communication net work and show how it can be augmented to handle conflict resolution.