Precedence of qos settings – Rockwell Automation 1783-WAPxxx Stratix 5100 Wireless Access Point User Manual User Manual

Page 459

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Rockwell Automation Publication 1783-UM006A-EN-P - May 2014

459

Configuring QoS

Chapter 16

The radio downstream flow is traffic transmitted out the access point radio

to a wireless client device. This traffic is the main focus for QoS on a
wireless LAN.

The radio upstream flow is traffic transmitted out the wireless client device

to the access point. QoS for wireless LANs does not affect this traffic.

The Ethernet downstream flow is traffic sent from a switch or a router to

the Ethernet port on the access point. If QoS is enabled on the switch or
router, the switch or router can prioritize and rate-limit traffic to the access
point.

The Ethernet upstream flow is traffic sent from the access point Ethernet

port to a switch or router on the wired LAN. The access point does not
prioritize traffic that it sends to the wired LAN based on traffic
classification.

Precedence of QoS Settings

When you enable QoS, the access point queues packets based on the Layer 2 class
of service value for each packet. The access point applies QoS policies in this
order:

Packets already classified

When the access point receives packets from a QoS-enabled switch or router that
has already classified the packets with non-zero 802.1Q/P user_priority values,
the access point uses that classification and does not apply other QoS policy rules
to the packets. An existing classification takes precedence over all other policies
on the access point.

QoS Element for Wireless Phones setting

If you enable the QoS Element for Wireless Phones setting, dynamic voice
classifiers are created for some of the wireless phone vendor clients, that lets the
wireless phone traffic to be a higher priority than other clients’ traffic.
Additionally, the QoS Basic Service Set (QBSS) is enabled to advertise channel
load information in the beacon and probe response frames. Some IP phones use
QBSS elements to determine the access point to associate to, based on the traffic
load.

IMPORTANT

Even if you have not configured a QoS policy, the access point always honors
tagged 802.1P packets that it receives over the radio interface.

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