C H A P T E R
36-1
Cisco IE 3000 Switch Software Configuration Guide
OL-13018-03
36
Configuring QoS
This chapter describes how to configure quality of service (QoS) by using automatic QoS (auto-QoS)
commands or by using standard QoS commands on the IE 3000 switch. With QoS, you can provide
preferential treatment to certain types of traffic at the expense of others. Without QoS, the switch offers
best-effort service to each packet, regardless of the packet contents or size. It sends the packets without
any assurance of reliability, delay bounds, or throughput.
You can configure QoS only on physical ports. You configure the QoS settings, such as classification,
queueing, and scheduling, and apply the policy map to a port.
Note
For complete syntax and usage information for the commands used in this chapter, see the command
reference
for this release.
This chapter consists of these sections:
•
Understanding QoS, page 36-1
•
Configuring Auto-QoS, page 36-19
•
Displaying Auto-QoS Information, page 36-27
•
Configuring Standard QoS, page 36-28
•
Displaying Standard QoS Information, page 36-68
The switch supports some of the modular QoS CLI (MQC) commands. For more information about the
MQC commands, see the “Modular Quality of Service Command-Line Interface Overview” at this site:
http://www.cisco.com/en/US/products/sw/iosswrel/ps1835/products_configuration_guide_chapter0918
6a00800bd908.html
Understanding QoS
Typically, networks operate on a best-effort delivery basis, which means that all traffic has equal priority
and an equal chance of being delivered in a timely manner. When congestion occurs, all traffic has an
equal chance of being dropped.
When you configure the QoS feature, you can select specific network traffic, prioritize it according to
its relative importance, and use congestion-management and congestion-avoidance techniques to
provide preferential treatment. Implementing QoS in your network makes network performance more
predictable and bandwidth utilization more effective.