QoS tools
We will describe the various QoS tools for implementing the DiffServ QoS model. The following figure depicts these tools as used on a router/switch:
Figure 9: QoS tools
Let's discuss these tools in detail in the upcoming sections.
Traffic conditioning
Traffic conditioning is performed at the edges of a DiffServ domain. Traffic conditioners perform traffic shaping and policing functions to ensure that traffic entering the DiffServ domain conforms to the rules specified by the Traffic Conditioning Agreement (TCA) and complies with the service provisioning policy of the domain. Traffic conditioning may range from simple code point re-marking to complex policing and shaping operations.
Policing
This feature allows you to limit the input or output transmission rate of a class of traffic based on user-defined criteria. It also enables the system to mark packets according to a user-defined criterion, such as the IP precedence value, the QoS group, or the DSCP value. Such traffic can then be...