Quality of Service Overview This chapter explains quality of
service (QoS) and the service models that embody it. It also
suggests benefits you can gain from implementing Cisco IOS QoS
in your network. Then it focuses on the Cisco IOS QoS features
and the technologies that implement them. To identify the
hardware platform or software image information associated with
a feature, use the Feature Navigator on Cisco.com to search for
information about the feature or refer to the software release
notes for a specific release. For more information, see the
“Identifying Supported Platforms” section in the “Using Cisco
IOS Software” chapter in this book. What Is Quality of Servic
QoS refers to the ability of a network to provide improved
service to selected network traffic over various underlying
technologies including Frame Relay, ATM, Ethernet and 802.1
networks, SONET, and IP-routed networks. In particular, QoS
features provide improved and more predictable network service
by providing the following services •Supp