Multimedia services, such as IPTV and video conferencing, have emerged to be an important part of the traffic sources in new communication systems requiring a High Speed IP switching. This book presents a scalable architecture of a high-performance IP switch which is based on Priority Active Queue Management (PAQM). It provides multimedia services with improved quality of service (QoS) for the communication system. Better Quality of service, in terms of delay, through-put and loss-rates, availability and security can be provided by using a packet scheduling technique and a buffer management architecture of packet switching networks. These techniques are applied to all kind of interconnected networks such as Wimax networks, ATM networks and IP networks.