Telecom operators and Internet service providers are heading for a new shift in communications paradigms. The forthcoming convergence of cellular and wireless data networks is often manifested in an "all IP approach" in which all communications are based on an end-to-end IP protocol framework. The approach to network design becomes user and service-centered, so that continuous reachability of mobile users and sustained communication capabilities are default requirements for a prospective architecture. In this article, we describe a network architecture which is able to provide seamless communication mobility, triggered either by the user or by the network, across multiple technologies. The architecture allows for media independent handovers and supports optimized mobility and resource management functions. The main focus of the article is on major technical highlights of mobility and quality-of-service (QoS) management subsystems for converged networks