Charging of SAML-based federated VoIP services

Whilst SAML-based federations are most often used by academic and semi-commercial institutions that focus only on attribute-based authentication, we foresee a growing interest for service providers providing charged services. Since more and more academic and semi-commercial federation participants offer Voice-over-IP (VoIP) services, this type of service provides an entry point into identity federation based payment. Therefore, this paper describes an approach on how to harmonize the SAML-based federation technology with the needs of a payment infrastructure for enabling charging of VoIP services within a federation. However, since the different aspects of our approach (SAML Payment, SIP Discovery and Tariff Function) are not bound to VoIP applications, each one of them could be used separately or combined for several service types.