Policy-based management is introduced and related to the specific needs of call control. It is explained how policies differ in important ways from features. Related work on policy-based management is reviewed, leading to the conclusion that a different approach is required for call control. A general architecture is presented for a policy system. This includes an overview of the major policy components, relating them to the system under control and to the context system that provides additional information. As a framework for explaining how policy conflicts are handled, the policy language for call control is briefly presented along with some sample policies. The paper then focuses on how policy conflicts are defined and resolved, using sample resolutions to illustrate the approach. Pointers are given to future enhancements to policy support, including new applications of policies to novel domains.
The final, definitive version of this article has been published in the Journal, Computer Networks 51 (2), 2007, © ELSEVIER.