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Configuring wireless QoS
Overview
An 802.11 network offers wireless access based on the carrier sense multiple access with collision
avoidance (CSMA/CA) channel contention. All clients accessing the WLAN have equal channel
contention opportunities, and all applications carried on the WLAN use the same channel contention
parameters. A live WLAN, however, is required to provide differentiated access services to address
diversified requirements of applications for bandwidth, delay, and jitter.
To provide applications with QoS services, IEEE developed 802.11e for the 802.11-based WLAN
architecture.
When IEEE 802.11e was being standardized, Wi-Fi Alliance defined the Wi-Fi Multimedia (WMM)
standard to allow QoS provision devices of different vendors to interoperate. WMM makes a WLAN
network capable of providing QoS services.
Terminology
WMM
WMM is a wireless QoS protocol designed to preferentially transmit packets with high priority, and
guarantees better QoS services for voice and video applications in a wireless network.
EDCA
Enhanced distributed channel access (EDCA) is a channel contention mechanism designed by WMM to
preferentially transmit packets with high priority and allocate more bandwidth to such packets.
Access category
WMM uses access categories (ACs) for handling channel contentions. WMM assigns WLAN data into
four access categories: AC-VO (voice), AC-VI (video), AC-BE (best-effort), and AC-BK (background), in
the descending order of priority. Each access category uses an independent priority queue for
transmitting data. When contention occurs, WMM guarantees that a high-priority access category
preempts a low-priority access category.
CAC
Connection admission control (CAC) limits the number of clients that are using high-priority access
categories (including AC-VO and AC-VI) to guarantee sufficient bandwidth for existing high-priority
traffic.
U-APSD
Unscheduled automatic power-save delivery (U-APSD) is a new power saving mechanism defined by
WMM to enhance the power saving capability of clients.
SVP
SpectraLink voice priority (SVP) is a voice priority protocol designed by the Spectralink company to
guarantee QoS for voice traffic.
Содержание WA2612-AGN
Страница 106: ...93 Figure 90 Create a static MAC address entry ...
Страница 126: ...113 Figure 116 Information about an IGMP snooping multicast entry ...
Страница 145: ...132 Enter 10 1 1 2 for Gateway Address c Click Apply Figure 133 Configure a dynamic address pool for the DHCP server ...
Страница 187: ...174 Figure 174 Firefox web browser setting ...
Страница 219: ...206 Figure 202 Common configuration area 6 Configure the advanced parameters ...
Страница 243: ...230 Number of users Real time accounting interval in minutes 500 to 999 12 1000 15 ...
Страница 278: ...265 Figure 266 Network diagram LAN Segment ...
Страница 339: ...326 Figure 348 Configure the wireless card I ...
Страница 340: ...327 Figure 349 Configure the wireless card II ...
Страница 346: ...333 Figure 357 Configure the wireless card II ...