Weighted Fair Queuing (Wfq); Multi-Bssid And Essid Access Ports - Symbol WS5000 Series System Reference Manual

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WS5000 Series Switch Overview

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.

1.3.5 Multi-BSSID and ESSID Access Ports

In a networked wireless environment, multiple access ports are connected to a WS5000 Series Switch to
provide RF connectivity to MUs. Each access port radio sends and receives RF signals over a range of space,
the Basic Service Set (BSS). The BSS coverage area is identified by a Basic Service Set Identifier (BSSID).
The access port beacon contains its BSSID, which enables the MU to recognize the access port and associate
with it. Extended Service Sets (ESS) are a logical group of BSSs. ESSs virtualize or increase the number of BSS
radio signals.
The beacon contains information about the access port and the network, which enables the MU to rank access
ports based on the received signal strength. The beacon can optionally include the Extended Service Set
Identifier (ESSID). MUs associate with the most preferable access port in the coverage area.
After association, the MU continues to scan for other beacons to ensure that it is receiving the best, continuous
signal strength, in case the signal from the currently associated access port becomes too weak to maintain
communications as the MU moves through the area.
Most access ports support multiple BSSs (see Access Port Support on page 1-4). MUs sense each unique BSS
as a separate radio signal. Access ports with multiple BSSs solve performance and security issues by isolating
broadcast traffic on a specific BSS rather than sending broadcasts to all BSSs. This enables MUs to save
battery power by sensing only for their specific BSS rather than all traffic. An access port with multiple BSSs