QoS overview

In data communications, Quality of Service (QoS) is a network's ability to provide differentiated service guarantees for diversified traffic in terms of bandwidth, delay, jitter, and drop rate.

Network resources are scarce. The contention for resources requires that QoS prioritize important traffic flows over trivial ones. For example, when bandwidth is fixed, more bandwidth for one traffic flow means less bandwidth for the other traffic flows. When making a QoS scheme, consider the characteristics of various applications to balance the interests of diversified users and to utilize network resources.

The following section describes some typical QoS service models and widely used, mature QoS techniques.