User Guide
Table Of Contents
- Cisco Wireless ISR and HWIC Access Point Configuration Guide
- Contents
- Preface
- Overview
- Configuring Radio Settings
- Enabling the Radio Interface
- Roles in Radio Network
- Configuring Network or Fallback Role
- Universal Client Mode
- Configuring Universal Client Mode
- Configuring Radio Data Rates
- Configuring Radio Transmit Power
- Configuring Radio Channel Settings
- Enabling and Disabling World Mode
- Enabling and Disabling Short Radio Preambles
- Configuring Transmit and Receive Antennas
- Disabling and Enabling Access Point Extensions
- Configuring the Ethernet Encapsulation Transformation Method
- Enabling and Disabling Reliable Multicast to Workgroup Bridges
- Enabling and Disabling Public Secure Packet Forwarding
- Configuring Beacon Period and DTIM
- Configuring RTS Threshold and Retries
- Configuring Maximum Data Retries
- Configuring Fragmentation Threshold
- Enabling Short Slot Time for 802.11g Radios
- Performing a Carrier Busy Test
- Configuring Multiple SSIDs
- Configuring an Access Point as a Local Authenticator
- Understand Local Authentication
- Configure a Local Authenticator
- Guidelines for Local Authenticators
- Configuration Overview
- Configuring the Local Authenticator Access Point
- Configuring Other Access Points to Use the Local Authenticator
- Configuring EAP-FAST Settings
- Limiting the Local Authenticator to One Authentication Type
- Unblocking Locked Usernames
- Viewing Local Authenticator Statistics
- Using Debug Messages
- Configuring Encryption Types
- Configuring Authentication Types
- Configuring RADIUS Servers
- Configuring and Enabling RADIUS
- Understanding RADIUS
- RADIUS Operation
- Configuring RADIUS
- Default RADIUS Configuration
- Identifying the RADIUS Server Host
- Configuring RADIUS Login Authentication
- Defining AAA Server Groups
- Configuring RADIUS Authorization for User Privileged Access and Network Services
- Starting RADIUS Accounting
- Selecting the CSID Format
- Configuring Settings for All RADIUS Servers
- Configuring the Access Point to Use Vendor-Specific RADIUS Attributes
- Configuring the Access Point for Vendor-Proprietary RADIUS Server Communication
- Configuring WISPr RADIUS Attributes
- Displaying the RADIUS Configuration
- RADIUS Attributes Sent by the Access Point
- Configuring and Enabling RADIUS
- Configuring VLANs
- Configuring QoS
- Channel Settings
- Protocol Filters
- Supported MIBs
- Error and Event Messages
- Glossary
- Index
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Cisco Wireless ISR and HWIC Access Point Configuration Guide
OL-6415-04
Chapter 9 Configuring QoS
Understanding QoS for Wireless LANs
Understanding QoS for Wireless LANs
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 QoS on the access point, you can select specific network traffic, prioritize it, and
use congestion-management and congestion-avoidance techniques to provide preferential treatment.
Implementing QoS in your wireless LAN makes network performance more predictable and bandwidth
utilization more effective.
When you configure QoS, you create QoS policies and apply the policies to the VLANs configured on
your access point. If you do not use VLANs on your network, you can apply your QoS policies to the
access point’s Ethernet and radio ports.
Note When you enable QoS, the access point uses Wi-Fi Multimedia (WMM) mode by default. See the “Using
Wi-Fi Multimedia Mode” section on page 9-4 for information on WMM.
QoS for Wireless LANs Versus QoS on Wired LANs
The QoS implementation for wireless LANs differs from QoS implementations on other Cisco devices.
With QoS enabled, access points perform the following:
• They do not classify packets; they prioritize packets based on DSCP value, client type (such as a
wireless phone), or the priority value in the 802.1q or 802.1p tag.
• They do not construct internal DSCP values; they only support mapping by assigning IP DSCP,
Precedence, or Protocol values to Layer 2 COS values.
• They carry out EDCF like queuing on the radio egress port only.
• They do only FIFO queueing on the Ethernet egress port.
• They support only 802.1Q/P tagged packets. Access points do not support ISL.
• They support only MQC policy-map set cos action.
• They prioritize the traffic from voice clients (such as Symbol phones) over traffic from other clients
when the QoS Element for Wireless Phones feature is enabled.
• They support Spectralink phones using the class-map IP protocol clause with the protocol value set
to 119.
To contrast the wireless LAN QoS implementation with the QoS implementation on other Cisco network
devices, see the Cisco IOS Quality of Service Solutions Configuration Guide at this URL:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fqos_c/index.htm
Impact of QoS on a Wireless LAN
Wireless LAN QoS features are a subset of the proposed 802.11e draft. QoS on wireless LANs provides
prioritization of traffic from the access point over the WLAN based on traffic classification.
Just as in other media, you might not notice the effects of QoS on a lightly loaded wireless LAN. The
benefits of QoS become more obvious as the load on the wireless LAN increases, keeping the latency,
jitter, and loss for selected traffic types within an acceptable range.