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
- QoS enforcement through built-in capabilities
Let's review external headers first.
DSCP and ToS headers
DSCP headers allow the firewall to let upstream and downstream devices know that certain sessions have a certain priority. These headers can be set in the security policies under the Actions tab, as in the following screenshot:
