As user applications continue to drive network growth and evolution, the demand to support various types of traffic is also increasing. Network traffic from business-critical and delay-sensitive applications must be serviced with priority and protected from other types of traffic. Quality of service (QoS) is a crucial element of any administrative policy that mandates how to handle application traffic on a network. QoS and its implementations in a converged network are complex and create many challenges for network administrators and architects. Many QoS building blocks or features operate at different parts of a network to create an end-to-end QoS system. Managing how these building blocks are assembled and how different QoS features are used can be a difficult task.

Cisco has simplified Quality of Service (QoS) configuration by logically grouping the various components of a QoS policy into reusable configuration modules. These modules constitute the Cisco modular QoS CLI (MQC), which allows network administrators and network implementers to deploy QoS easily. Cisco also provides many mechanisms that assist in the development and monitoring of QoS implementations. These mechanisms allow administrators to perform network discoveries that assist in planning QoS policy and provide monitoring statistics that are used to perform ongoing validation of QoS configurations. There are some instances, however, in which customers do not want to be concerned with the specifics of QoS configuration. These customers would prefer to enable QoS in the LAN or WAN by using one or two commands and to allow the Cisco IOS router or switch to automate the required complex QoS configuration. For these customers, Cisco has developed Cisco AutoQoS.

After network traffic is classified, individual packets are colored or marked so that other network devices can apply QoS features uniformly to those packets in compliance with the defined QoS policy. Marking the network traffic allows you to set or modify the attributes for traffic belonging to a specific class. When used in conjunction with network traffic classification, marking the network traffic is the foundation for enabling many quality of service (QoS) features on your network.

After network traffic is classified, individual packets are colored or marked so that other network devices can apply QoS features uniformly to those packets in compliance with the defined QoS policy. Marking the network traffic allows you to set or modify the attributes for traffic belonging to a specific class. When used in conjunction with network traffic classification, marking the network traffic is the foundation for enabling many quality of service (QoS) features on your network.