Welcome to the third International Conference on Management of Multimedia Networks and Services (MMNS'2000) in Fortaleza (Brazil)! The first MMNS was held in Montreal ( Canada) in july 1997 and the second MMNS was held in Versailles (France) in November 1998. The MMNS conference takes place every year and a half and is aimed to be a truly international event by bringing together researchers and practitioners from all around the world and by organising the conference each time in a different continent/country. Over the past several years, there has been a considerable amount of research within the fields of multimedia networking and network management. Much of that work has taken place within the context of managing Quality-of­ Service in broadband integrated services digital networks such as the A TM, and more recently in IP-based networks, to respond to the requirements of emerging multimedia applications. A TM networks were designed to support multimedia traffic with diverse characteristics and can be used as the transfer mode for both wired and wireless networks. A new set of Internet protocols is being developed to provide better quality of service, which is a prerequisite for supporting multimedia applications. Multimedia applications have a different set of requirements, which impacts the design of the underlying communication network as well as its management. Several QoS management mechanisms intervening at different layers of the communication network are required including QoS-routing, QoS-based transport, QoS negotiation, QoS adaptation, FCAPS management, and mobility management.