Protocols And Standards; Hardware Compatibility With Wlan; Configuring Wmm; Configuration Restrictions And Guidelines - H3C MSR Series Configuration Manual

receives the trigger packet, packets in the transmit queue are sent. The number of sent packets
depends on the agreement made when the client was admitted. AC queues without the delivery
attribute store and transmit packets as defined in the 802.11 protocol.
SVP
SVP can assign packets with the protocol ID 119 in the IP header to a specific AC queue. SVP
stipulates that random backoff is not performed for SVP packets. Therefore, you can set both
ECWmin and ECWmax to 0 when there are only SVP packets in an AC queue.
ACK policy
WMM defines two ACK policies:
•
No ACK—When the no acknowledgement (No ACK) policy is used, the recipient does not
acknowledge received packets during wireless packet exchange. This policy is suitable in the
environment where communication quality is fine and interference is weak. While the No ACK
policy helps improve transmission efficiency, it can cause increased packet loss when
communication quality deteriorates. This is because when this policy is used, a sender does not
retransmit packets that have not been received by the recipient.
•
Normal ACK—When the Normal ACK policy is used, the recipient acknowledges each
received unicast packet.

Protocols and standards

•
802.11e-2005, Amendment 8: Medium Access Control (MAC) Quality of Service
Enhancements, IEEE Computer Society, 2005
•
Wi-Fi, WMM Specification version 1.1, Wi-Fi Alliance, 2005

Hardware compatibility with WLAN

WLAN is not available on the following routers:
•
MSR 2600.
•
MSR 30-11.
•
MSR 30-11E.
•
MSR 30-11F.
•
MSR3600-51F.

Configuring WMM

Configuration restrictions and guidelines

•
If CAC is enabled for an AC queue, CAC is also enabled for the AC queues with higher priority.
For example, if you use the wmm edca client command to enable CAC for the AC-VI queue,
CAC is also enabled for the AC-VO queue. However, enabling CAC for the AC-VO queue does
not enable CAC for the AC-VI queue.
•
H3C recommends that you use the default EDCA parameter settings for APs and clients
(except the TXOPLimit parameter for devices using 802.11b radio cards) unless it is necessary
to modify the default settings.
•
When the radio card of a device is 802.11b, H3C recommends that you set the TXOPLimit
values of the AC-BK, AC-BE, AC-VI, and AC-VO queues to 0, 0, 188, and 102, respectively.
•
The SVP packet mapping function takes effect only after you enable WMM.
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