Wireless/Redundant Edge Services xl Module Management and Configuration Guide WS.01.03 or greater

3-83
Wireless Local Area Networks (WLANs)
Traffic Management (QoS)
Note If you change the protocol in one queue, the setting automatically changes
in the other three queues; in other words, it applies to the WLAN as a
whole. (It does not make sense to use 802.1p to place traffic in the
background queue, but DSCP to place traffic in the voice queue.)
7. Select OK.
Enabling Prioritization of Voice Traffic
Voice prioritization improves the QoS for traffic destined to VoWLAN devices.
The Wireless Edge Services xl Module configures RPs to monitor all packets
from stations in a WLAN; if the IP type in a packet’s header indicates that it is
a voice packet, the module marks all traffic destined to the packet’s source as
high-priority voice packets.
Traffic destined to the VoWLAN device thus receives priority handling both in
the Ethernet network (from the wireless services-enabled switch to the RP)
and in the wireless network (from the RP to the VoWLAN device). The wireless
services-enabled switch forwards the traffic in its high-priority queue, and the
RP uses its Voice queue settings.
Voice prioritization thus helps to maintain QoS for VoWLAN devices that do
not support WMM on their own.
To enable the Wireless Edge Services xl Module to prioritize traffic to voice
stations in a particular WLAN, follow these steps:
1. Select Network Setup > WLAN Setup > Configuration.
2. Select the WLAN that includes voice devices and click Edit.
3. Under Advanced, check the Use Voice Prioritization box.
Specifying a WLAN’s QoS Weight
The Wireless Edge Services xl Module implements WFQ on its internal down-
link port. When the module receives traffic from the wired network, it divides
the traffic into a separate queue for each RP. If you have enabled WLAN
prioritization, it further divides the traffic into separate queues for each
WLAN.
The Wireless Edge Services xl Module then weighs these queues according to
the WLAN’s weight. If you specify a greater weight for a WLAN, the module
more often chooses to transmit traffic in the corresponding queue, and traffic
destined to that WLAN receives relatively more bandwidth.