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Overview 1 - 13
1.2.2.12 Power Save Polling
An MU uses
Power Save Polling
(PSP) to reduce power consumption. When an MU is in PSP mode, the switch buffers its
packets and delivers them using the DTIM interval. The PSP-Poll packet polls the AP for buffered packets. The PSP null
data frame is used by the MU to signal the current PSP state to the AP.
1.2.2.13 QoS
QoS provides a data traffic prioritization scheme. QoS reduces congestion from excessive traffic.
If there is enough bandwidth for all users and applications (unlikely because excessive bandwidth comes at a very high
cost), then applying QoS has very little value. QoS provides policy enforcement for mission-critical applications and/or
users that have critical bandwidth requirements when the switch’s bandwidth is shared by different users and
applications.
QoS helps ensure each WLAN on the switch receives a fair share of the overall bandwidth, either equally or as per the
proportion configured. Packets directed towards MUs are classified into categories such as Management, Voice and Data.
Packets within each category are processed based on the weights defined for each WLAN.
The switch supports the following QoS mechanisms:
802.11e QoS
802.11e enables real-time audio and video streams to be assigned a higher priority over data traffic. The switch supports
the following 802.11e features:
• Basic WMM
• WMM Linked to 802.1p Priorities
• WMM Linked to DSCP Priorities
• Fully Configurable WMM
• Admission Control
• Unscheduled-APSD
• TSPEC Negotiation
• Block ACKQBSS Beacon Element
802.1p Support
802.1p is a standard for providing QoS in 802-based networks. 802.1p uses three bits to allow switches to re-order packets
based on priority level.
Voice QoS
When switch resources are shared between a
Voice over IP
(VoIP) conversation and a file transfer, bandwidth is normally
exploited by the file transfer, thus reducing the quality of the conversation or even causing it to disconnect. With QoS, a
VoIP conversation (a real-time session), receives priority, maintaining a high level of voice quality. Voice QoS ensures:
• Strict Priority
• Spectralink Prioritization
• VOIP Prioritization (IP ToS Field)
• Multicast Prioritization
Summary of Contents for WiNG 4.4
Page 1: ...Motorola Solutions WiNG 4 4 SYSTEM REFERENCE GUIDE ...
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Page 3: ...MOTOROLA SOLUTIONS WING 4 4 SYSTEM REFERENCE GUIDE 72E 157062 01 Revision A January 2012 ...
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