Quality of service (QoS) refers to the description or measurement of the overall performance of a service, such as a telephony or computer network, or a cloud computing service, particularly the performance seen by the users of the network. QoS is the ability to provide different priorities to different applications, users, or data flows, or to guarantee a certain level of performance to a data flow. In the field of computer networking and other packet-switched telecommunication networks, QoS refers to traffic prioritization and resource reservation control mechanisms rather than the achieved service quality.
QoS is important for real-time streaming multimedia applications such as voice over IP, multiplayer online games, and IPTV, since these often require fixed bit rate and are delay-sensitive. QoS is especially important in networks where the capacity is a limited resource, for example in cellular data communication. QoS controls and manages network traffic to reduce packet loss, latency, and jitter on a network. QoS is used to prioritize traffic, which includes offering dedicated bandwidth, controlled jitter, and lower latency.
QoS is important because enterprises need to provide stable services for employees and customers to use. Quality of service determines quality of experience (QoE). If the services an organization provides are not reliable, customer and employee relationships may be put at risk. Additionally, data integrity and security are more likely to be compromised in a company with poor QoS. In general, employees and customers depend on communication services to do their jobs. When QoS suffers, quality of work and QoE suffer as well.
QoS can be achieved through various mechanisms and technologies, such as bandwidth management, mean opinion score, and prioritization for all traffic. QoS mechanisms give network administrators the power to prioritize applications as determined by the needs of the business. This makes it easy to assign higher importance to particular data delivery types over others.
