Cisco ASA 5506-X Configuration Manual page 275

Quality of Service
Have you ever participated in a long-distance phone call that involved a satellite connection? The
conversation might be interrupted with brief, but perceptible, gaps at odd intervals. Those gaps are the
time, called the latency, between the arrival of packets being transmitted over the network. Some network
traffic, such as voice and video, cannot tolerate long latency times. Quality of service (QoS) is a feature
that lets you give priority to critical traffic, prevent bandwidth hogging, and manage network bottlenecks
to prevent packet drops.
Note For the ASASM, we suggest performing QoS on the switch instead of the ASASM. Switches have more
capability in this area. In general, QoS is best performed on the routers and switches in the network,
which tend to have more extensive capabilities than the ASA.
This chapter describes how to apply QoS policies.
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About QoS
You should consider that in an ever-changing network environment, QoS is not a one-time deployment,
but an ongoing, essential part of network design.
This section describes the QoS features available on the ASA.
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About QoS, page 12-1
Guidelines for QoS, page 12-3
Configure QoS, page 12-4
Monitor QoS, page 12-9
Configuration Examples for Priority Queuing and Policing, page 12-11
History for QoS, page 12-13
Supported QoS Features, page 12-2
What is a Token Bucket?, page 12-2
Policing, page 12-2
Priority Queuing, page 12-3
DSCP (DiffServ) Preservation, page 12-3
C H A P T E R
Cisco ASA Series Firewall CLI Configuration Guide
12
12-1