Weighted Fair Queuing (Wfq); Qos Via Wi-Fi Multimedia Extension (Wme) - Symbol WS5000 Series System Reference Manual

1.3.4.3 Weighted Fair Queuing (WFQ)

Weighted Fair Queuing (WFQ) enables a mechanism on the switch that uses up to eight queues to store data—
network packets—and prioritize RF transmission to and from MUs depending on the data type. After the
switch classifies the data (as voice or data), WFQ stores the packets (assuming the network traffic demands
that the data be queued by data type) and then transmits the packets at a rate specified by the WFQ allocation
percentage setting.
You can assign WFQs to classification groups. There is a WFQ for inbound traffic. WFQ for a classification
group must have a nonzero value to enable the classification group.
Note You can use WFQ to prioritize only UDP traffic along with the filters.
WFQ uses one queue for each classification group, up to eight queues total, and one queue for all other data.
For example, if the network has only one classification group for VoIP and no other groups, then WGQ
automatically uses two queues: one for VoIP and the other for all other data (data not defined in the
classification group). Each additional classification group uses another queue and keeps one queue open for
other data.
The allocation setting determines the percentage of available network bandwidth for data from a classification
group. For example, if the WFQ allocation for VoIP data is set to 80%, then the switch sends four packets of
VoIP data every one packet of other data during periods of network congestion.
WFQ is implemented for the different types of traffic on the same ESSID and Access Port (AP) as well as
between different ESSIDs on the same AP. This implementation shares voice and non-voice traffic across
different network paths, thereby balancing the traffic load. A large volume of non-voice traffic on one ESSID
does not deplete the voice traffic on another ESSID on the same AP.

1.3.4.4 QoS via Wi-Fi Multimedia Extension (WME)

Quality of Service (QoS) is required to support multimedia applications and advanced traffic management.
WME (Wi-Fi Multimedia Extension) adds prioritized QoS capabilities to Wi-Fi networks and optimizes their
performance when multiple concurring applications, each with different latency and throughput requirements,
compete for network resources.
By using WME, end-user satisfaction is maintained in a wider variety of environments and traffic conditions.
WMM provides prioritized media access and is based on the Enhanced Distributed Channel Access (EDCA)
method.
It defines four priority classes to manage traffic from different applications:
• Voice
• Video
• Best effort,
• Background
Typically, networks operate on a best-effort delivery basis. 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.
Applications such as voice, video and music streaming, and interactive gaming generate data streams that
have strict latency and throughput requirements. To ensure a good user experience, traffic from different
applications has to be managed and prioritized using QoS.
WS5000 Series Switch Overview
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