The design of an extended and generic Authentication, Authorization, Accounting, and Charging Architecture (AAAC Arch.) has been performed within the IST project MobyDick. In addition, this architecture has been implemented to address MobyDick's main objective: to facilitate the deployment of a ubiquitous mobile IPv6-based, Quality-of-Service (QoS)-aware infrastructure through a flexible and evolutionary AAAC Architecture. While the AAAC Arch, is based on the DIAMETER protocol, basic concepts developed cover session and services models, user profiles to allow for user mobility and QoS-aware authorization. Based on those basic building blocks for the extended AAAC Arch., the implementation of user registration, service authorization, metering, accounting, charging, and auditing is discussed. The paper closes with the presentation of the two trial sites used and their testbeds.