Quality of Service
In the fields of packet-switched networks and computer networking, the traffic engineering term Quality of Service refers to control mechanisms that can provide different priority to different users or data flows, or guarantee a certain level of performance to a data flow in accordance with requests from the application program. Quality of Service guarantees are important if the network capacity is limited, especially for real-time streaming multimedia applications, for example voice over IP and IP-TV, since these often require fixed bit rates and may be delay sensitive.