Network Security Principles and Practices

Overview of NBAR

NBAR is an intelligent classification engine implemented in Cisco IOS Software. NBAR's primary function is related to QoS (quality of service). The goal of QoS implementations in Cisco IOS Software is to ensure higher QoS to certain types of traffic in terms of bandwidth allocation, priority queuing, delay, jitter, and packet loss. This means that because Cisco IOS Software has mechanisms built in, it can give certain types of traffic precedence over others in terms of the elements just described. However, in order to achieve this goal, the packets passing through a router need to be classified or tagged first. After this has been done, QoS features can be applied to these differentiated classes, and priority can be given to ...