Controlling the bandwidth with quality-of-service policies

Quality of Service (QoS) is the collective name for several technologies that can help improve the quality of applications, and the data flows that they are applied to, by prioritizing them over other flows or reserving bandwidth to ensure adequate throughput and acceptable latency. In this section, you will learn how QoS marking can be applied to a firewall to interact with network devices downstream.

There are two ways for a firewall to participate in applying QoS to network traffic:

• Differentiated Services Code Point (DSCP) and Type of Service (ToS) headers, which are “external” markings introduced by a network device or host and intended to be carried all the way to the final destination or until the header is stripped, ensuring all devices in the path are aware of the weight or priority of a packet
• QoS enforcement through built-in capabilities, which does not alter the header of the...