Техническая Инструкция для Cisco Cisco IOS XE 3.5E
Components Used
The information in this document is based on these software and hardware versions:
Cisco Catalyst 3850 switch that runs Cisco IOS
®
XE Software Release 3.2.2(SE)
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Cisco 5760 Wireless LAN controller that runs Cisco IOS XE Software Release 3.2.2(SE)
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Cisco 3600 Series Lightweight Access Points
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The information in this document was created from the devices in a specific lab environment. All of the
devices used in this document started with a cleared (default) configuration. If your network is live, make sure
that you understand the potential impact of any command.
devices used in this document started with a cleared (default) configuration. If your network is live, make sure
that you understand the potential impact of any command.
Background Information
QoS refers to the ability of the network to provide better or special service to a set of users or applications to
the detriment of other users or applications.
the detriment of other users or applications.
With QoS, bandwidth can be managed more efficiently across LANs, which includes wireless LANs
(WLANs) and WANs. QoS provides enhanced and reliable network service with these services:
(WLANs) and WANs. QoS provides enhanced and reliable network service with these services:
Supports dedicated bandwidth for critical users and applications.
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Controls the jitter and latency that is required by real−time traffic.
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Manages and minimizes network congestion.
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Shapes network traffic in order to smooth the flow of traffic.
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Sets network traffic priorities.
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In the past, WLANs were mainly used to transport low−bandwidth, data−application traffic. With the
expansion of WLANs into vertical (such as retail, finance, and education) and enterprise environments,
WLANs are now used to transport high−bandwidth data applications in conjunction with time−sensitive,
multimedia applications. This requirement led to the necessity for wireless QoS.
expansion of WLANs into vertical (such as retail, finance, and education) and enterprise environments,
WLANs are now used to transport high−bandwidth data applications in conjunction with time−sensitive,
multimedia applications. This requirement led to the necessity for wireless QoS.
The IEEE 802.11e working group within the IEEE 802.11 standards committee has completed the standard
definition, and the Wi−Fi Alliance has created the Wi−Fi Multimedia (WMM) certification, but the adoption
of the 802.11e standard is still limited. Most devices are WMM−certified, because WMM certification is
needed for 802.11n and 802.11ac certification. Many wireless devices do not assign different QoS levels to
packets sent to the Data Link Layer, so those devices send most of their traffic with no QoS marking and no
relative prioritization. However, most 802.11 Voice over Wireless LAN (VoWLAN) IP phones do mark and
prioritize their voice traffic. This document focuses on QoS configuration for VoWLAN IP phones and on
video−capable wi−fi devices that mark their voice traffic.
definition, and the Wi−Fi Alliance has created the Wi−Fi Multimedia (WMM) certification, but the adoption
of the 802.11e standard is still limited. Most devices are WMM−certified, because WMM certification is
needed for 802.11n and 802.11ac certification. Many wireless devices do not assign different QoS levels to
packets sent to the Data Link Layer, so those devices send most of their traffic with no QoS marking and no
relative prioritization. However, most 802.11 Voice over Wireless LAN (VoWLAN) IP phones do mark and
prioritize their voice traffic. This document focuses on QoS configuration for VoWLAN IP phones and on
video−capable wi−fi devices that mark their voice traffic.
Note: QoS configuration for devices that do not perform internal marking is outside the scope of this
document.
document.
The 802.11e amendment defines eight user priority (UP) levels, grouped two by two into four QoS levels
(access categories):
(access categories):
Platinum/Voice (UP 7 and 6) − Ensures a high quality of service for voice over wireless.
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Gold/Video (UP 5 and 4) − Supports high−quality video applications.
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Silver/Best Effort (UP 3 and 0) − Supports normal bandwidth for clients. This is the default setting.
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Bronze/Background (UP 2 and 1) − Provides the lowest bandwidth for guest services.
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Platinum is commonly used for VoIP clients and Gold for video clients. This document provides a
configuration example that illustrates how to configure QoS on controllers and communicate with a wired
configuration example that illustrates how to configure QoS on controllers and communicate with a wired