user manual

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Cisco Aironet 1200 Series Access Point Software Configuration Guide

OL-2159-05

Chapter 1 Overview

Quality of Service Support

What is QoS?

QoS refers to the ability of a network to provide improved service to selected network traffic over various

underlying technologies including Ethernet and wireless LANs. In particular, QoS features provide

improved and more predictable network service by providing the following services:

• Improving loss characteristics

• Avoiding and managing network congestion

• Prioritizing service to different kinds of network traffic

• Shaping network traffic

• Setting traffic priorities across the network

Limitations and Restrictions

The QoS implementation on the access point has the following limitations and restrictions:

• Provides only prioritized QoS for downlink traffic on IEEE 802.11 links and does not support a

general purpose QoS signalling protocol, uniform admission control, guaranteed bandwidth, and

other features that are generally associated with parametized QoS.

• Supports rudimentary admission control mechanisms for Spectralink and Symbol VoIP phones.

• Does not provide a method for prioritizing uplink traffic on IEEE 802.11 links.

• Does not offer 802.1X authentication for Symbol VoIP phones because those phones do not support

an 802.1X type such as LEAP or EAP-TLS.

• The DTIM beacon period must be small to support jitter-sensitive streaming multicast audio and

video applications.

• Supports IEEE 802.11e EDCF-like channel access prioritization but does not support IEEE 802.11e

QoS frame formats.