Constraint-Based Policy Negotiation and Enforcement for Telco Services

Telco services are evolving under several aspects: for instance, services may combine different telecommunication features (messaging, multi-media, etc.) and may be activated and controlled by applications deployed in a 3rd party domain. Telco infrastructures are following this trend by adopting service oriented architecture solutions, e.g. for composing services and for introducing uniform interaction models among services. In a SOA-based system, capabilities, requirements and general features of services can be expressed in terms of policies. Such policies are negotiated in order to define a service level agreement among the involved parties. In this paper we show how to specify, negotiate, and enforce policies for Telco services by using a constraint-based model, the cc-pi calculus. This language extends concurrent constraint programming with synchronous communication and local names, and with the notion of soft constraints, that generalise classical constraints to represent preference levels. In cc-pi calculus, policies are expressed as soft constraints and the parties involved in the negotiation as communicating processes. The model allows to specify complex scenarios in which policy negotiations and validations can be arbitrarily nested

Comments on “logic programming with equations”

AbstractThis note discusses the results of the compilational approach of equational logic programming developed by Van Emden and Yukawa, and compares them with similar results obtained by Bosco et al. and by Fribourg. We show that Van Emden and Yukawa's completeness result contains an inaccuracy, and we suggest how to correct it