wmm

Configures 802.11e WMM (wireless multi media) parameters

Supported in the following platforms:

  • Access Points — AP505i, AP510i/e, AP560i/h
  • Service Platforms — NX5500, NX7500, NX9500, NX9600, VX9000

Syntax

wmm [background|best-effort|video|voice]
wmm [background|best-effort|video|voice] [aifsn <1-15>|cw-max <0-15>|cw-min <0-15>|
txop-limit <0-65535>]

Parameters

wmm [background|best-effort|video|voice] [aifsn <1-15>|cw-max <0-15>|cw-min <0-15>|
txop-limit <0-65535>]

wmm background

Configures background access category wireless multimedia settings

wmm best-effort

Configures best effort access category wireless multimedia settings

wmm video

Configures video access category wireless multimedia settings

wmm voice

Configures voice access category wireless multimedia settings

aifsn <1-15>

Configures AIFSN (Arbitrary Inter-Frame Space Number) as the wait time between data frames derived from the AIFSN and slot time

  • background – Sets the current AIFSN for low (background) traffic. The default is 7.

  • best-effort – Sets the current AIFSN for normal (best-effort) traffic. The default is 3.

  • video – Set the current AIFSN for video traffic. Higher-priority traffic video categories should have lower AIFSNs than lower-priority traffic categories. This causes lower-priority traffic to wait longer before attempting access. The default is 1.

  • voice – Sets the current AIFSN for voice traffic. Higher-priority traffic voice categories should have lower AIFSNs than lower-priority traffic categories. This causes lower-priority traffic to wait longer before attempting access. The default is 1.

The following keyword is common to all of the above traffic types:

  • <1-15> – Sets a value from 1 - 15

cw-max <0-15>

Clients pick a number between 0 and the min contention window to wait before retransmission. Clients then double their wait time on a collision, until it reaches the maximum contention window.

  • background – Sets CW Max for low (background) traffic. The default is 10.
  • best-effort – Sets CW Max for normal (best effort) traffic. The default is 6.
  • voice – Sets CW Max for voice traffic. The default is 3.
  • video – Sets CW Max for video traffic. The default is 4

The following keyword is common to all of the above traffic types:

  • <0-15> – ECW: the contention window. The actual value used is (2^ECW - 1).

Lower values are used for higher priority traffic (like video and voice) and higher values are used for lower priority traffic (like background and best-effort).

cw-min <0-15>

Clients select a number between 0 and the min contention window to wait before retransmission. Clients then double their wait time on a collision, until it reaches the maximum contention window.

  • background – Sets CW Min for low (background) traffic. The default is 4.

  • best-effort – Sets CW Min for normal (best effort) traffic. The default is 4.

  • voice – Sets CW Min for voice traffic. The default is 2.

  • video – Sets CW Min for video traffic. The default is 3.

The following keyword is common to all of the above traffic types:

  • <0-15> – ECW: the contention window. The actual value used is (2^ECW - 1).

Lower values are used for higher priority traffic (like video and voice) and higher values are used for lower priority traffic (like background and best-effort).

txop-limit <0-65535>

Set the interval, in microseconds, during which a particular client has the right to initiate transmissions

  • background – Sets TXOP for low (background) traffic. The default is 0.

  • best-effort – Sets TXOP for normal (best effort) traffic. The default is 4.

  • voice – Sets TXOP for voice traffic. The default is 47.

  • video – Sets TXOP for video traffic. The default is 94.

The following keyword is common to all of the above traffic types:

  • <0-65535> – Specify a value from 0 - 65535 to configure the transmit opportunity limit in 32 microsecond units.

Lower values are used for higher priority traffic (like video and voice) and higher values are used for lower priority traffic (like background and best-effort).

Usage Guidelines

Before defining a radio QoS policy, refer to the following deployment guidelines to ensure the configuration is optimally effective:

  • To support QoS, each multimedia application, wireless client, and WLAN is required to support WMM.

  • WMM enabled clients can co-exist with non-WMM clients on the same WLAN. Non-WMM clients are always assigned a Best Effort access category.

  • Default WMM values are recommended for all deployments. Changing these values can lead to unexpected traffic blockages, and the blockages might be difficult to diagnose.

  • Overloading an access point radio with too much high priority traffic (especially voice) degrades overall service quality for all users.

  • TSPEC admission control is only available with newer voice over WLAN phones. Many legacy voice devices do not support TPSEC or even support WMM traffic prioritization.

Examples

nx9500-6C8809(config-radio-qos-test)#wmm best-effort aifsn 7
nx9500-6C8809(config-radio-qos-test)#wmm voice txop-limit 1
nx9500-6C8809(config-radio-qos-test)#show context
radio-qos-policy test
 wmm best-effort aifsn 7
 wmm voice txop-limit 1
 admission-control voice max-airtime-percent 9
 admission-control voice reserved-for-roam-percent 8
 accelerated-multicast stream-threshold 15
nx9500-6C8809(config-radio-qos-test)#

Related Commands

no (schedule-policy-config-mode-commands)

Reverts or resets 802.11e/wireless multimedia settings to their default