Precedence Of Qos Settings; Using Wi-Fi Multimedia Mode - Cisco C3201FESMIC-TP= - 3201 Fast EN Switch Mobile Interface Card Expansion Module Software Configuration Manual

QoS in a Wireless Environment

Precedence of QoS Settings

When you enable QoS, the WMIC queues packets based on the Layer 2 class of service value for each
packet. The WMIC applies QoS policies in this order:
1.
Note
2.
3.

Using Wi-Fi Multimedia Mode

When you enable QoS, the access point uses Wi-Fi Multimedia (WMM) mode by default.
The following features of the WMM specification are supported:
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Packets already classified—When the WMIC 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 WMIC 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 WMIC.
The WMIC always acts on tagged 802.1P packets that it receives over the radio interface, even
if a QoS policy has not been configured.
Policies you create on the WMIC—QoS Policies that you create and apply to VLANs or to the
WMIC interfaces are second in precedence after previously classified packets.
Default classification for all packets on VLAN—If you set a default classification for all packets on
a VLAN, that policy is third in the precedence list.
Addition of the WMM information element to associate request frames
Addition of the WMM parameter element to the beacon, probe response and association response
frames
Addition of the QoS control field to data frames
Support for setting the field sent in the WMM parameter element (per access class):
contention window (CW) min
–
CW max
–
Aifs
–
– Admission control required
– Transmit opportunity (TXOP) size
Separate transmit sequence numbers for each access class and for frames that do not have the QoS
control field
Separate duplicate sequence number checking lists on receive for each access class and for frames
that do not have the QoS control field
No ACK frames for QOS control fields that do not require ACK
Negotiation of WMM capability with client on reassociation
Support for burst transmission of multiple frames in a transmit opportunity
Support for the WMM specified backoff procedure
Support for the WMM retransmit procedure
Addition of 802.1d priority for WMM enabled clients
Cisco 3200 Series Wireless MIC Software Configuration Guide
Understanding QoS for Wireless LANs
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