Quality of Service (QoS) is a set of service requirements that the network must meet in order to ensure an adequate service level for data transmission. These service requirements are based on industry standards for QoS functionality.
QoS allows real-time programs to make the most efficient use of network bandwidth. Because QoS provides some level of guarantee for sufficient network resources, it gives a shared network a level of service similar to that of a dedicated network.
A QoS guarantee indicates a service level that enables a program to transmit data at a specified rate and to deliver it within a specified time frame.
QoS model
The goal of QoS is a guaranteed delivery system for network traffic, such as Internet Protocol (IP) packets.