Charging and Accounting for QoS-Enhanced IP Multicast

fu this paper we propose a layered framework for charging QoS-enhanced IP services with policy based configuration of its layers. As an example ar­ chitecture we present our implementation - Value Added IP Charging and Ac­ counting Service (VIPCAS). We further concentrate on VIPCAS elements for policies and data exchange. As flexible data structure for exchange of ac­ counting information, we propose the Premium IP Network Accounting Rec­ ord (PIP-NAR), which is suitable for a variety of charging schemes (e.g. charging of reserved and used resources), and which also makes provider­ specific extensions possible. We specify the Tariff Formula Language (TFL) for representing tariff policies, and the Charging fuformation Protocol (CIP) for distributing tariff information expressed in TFL. For a fair charging of IP Multicast services, cost sharing functions should be supported at both the ac­ counting and the charging layer. We evaluate different approaches in this area which support receiver heterogeneity with regard to the reserved QoS.