Controller Based WLANs

How do I optimize wireless for multicast video streaming?

Question:  How do I optimize wireless for multicast video streaming?

 

Product and Software: This article applies to the Aruba 600, 3000, and M3 series controllers running ArubaOS 3.4.1.0 and later.

This article is a best practice cheat sheet for successful multicast video streaming using the Aruba infrastructure. Multicast video streaming involves several pieces in the network and some of them should be optimized to provide the best quality video end-to-end.

Suggested Optimizations:

1) Use end-to-end Gigabit Ethernet links from multicast server to Aruba controller to Aruba APs. These links help to provide the best throughput to the wireless clients.

2) Adjust the multicast server or encoder's video frame size to not exceed the maximum frame size on any wired network. Several deployments have successfully streamed a video frame size of 1400 bytes. This adjustment helps reduce fragmentation in the air.

3) Enable IGMP proxy on the controller for the wireless VLANs.

Example

For wireless VLAN 888, configure the following commands on the controller when its uplink interface is Gigabit Ethernet slot 1 port 3.

config t

interface vlan 888

ip igmp proxy gigabitethernet 1/3

end

write memory

4) Enable Quality of Service (QoS) tagging for the multicast video traffic. It is best to enable this end-to-end, but it should be at least enabled on the controller so that it can be prioritized to the correct video queue.

Example

To provide QoS tagging from traffic destined from the uplink to the wireless client when using multicast IP address "239.192.38.143", issue the following commands. Note that some customers create a rule for the entire multicast network (224.x.x.x to 239.x.x.x).

config t

netdestination mcast-video

host 239.192.38.143

exit

ip access-list session mcast_video_acl

any alias mcast-video any permit tos 40

any any any permit

exit

interface gigabitethernet 1/3

ip access-group mcast_video_acl session

end

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5) Enable Dynamic Multicast Optimization (DMO) on the WLAN virtual AP where wireless clients will view video streams. Also, set the threshold to a number that is higher than the maximum amount of users on a single AP that would view the stream. For example, if a maximum of 15 abg clients and 15 n clients on an AP would view the multicast video stream, then set the DMO threshold to 60. This setting enhances the way the controller will deliver the video to the wireless clients.

Example

To enable DMO on the "wlan virtual-ap CorpNet-vap_prof" virtual AP, issue the following commands:

config t

wlan virtual-ap CorpNet-vap_prof

dynamic-mcast-optimization

dynamic-mcast-optimization-thresh 60

end

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6) Verify that video aware scan is enabled in the ARM profile. This setting helps the AP provide quality video to the wireless clients by not scanning when users are receiving video streams.

Example

The following example shows how to verify if "video aware scan" is enabled in the ARM profile "default", which is applied to the rf dot11a and dot11g radio profile by default.

show rf arm-profile default


Adaptive Radio Management (ARM) profile "default"
-------------------------------------------------
Parameter Value
--------- -----
Assignment single-band
Allowed bands for 40MHz channels a-only
Client Aware Enabled
Max Tx EIRP 127 dBm
Min Tx EIRP 9 dBm
Multi Band Scan Enabled
Rogue AP Aware Disabled
Scan Interval 10 sec
Active Scan Disabled
Scanning Enabled
Scan Time 110 msec
VoIP Aware Scan Disabled
Power Save Aware Scan Enabled
Video Aware Scan Enabled <----This should show "enabled".
Ideal Coverage Index 10
Acceptable Coverage Index 4
Free Channel Index 25
Backoff Time 240 sec
Error Rate Threshold 50 %
Error Rate Wait Time 30 sec
Noise Threshold 75 -dBm
Noise Wait Time 120 sec
Minimum Scan Time 8
Load aware Scan Threshold 1250000 Bps
Mode Aware Arm Disabled

If video aware scan is not enabled, enable it in the ARM profile called "default", by issuing the following commands:

config t

rf arm-profile default

video-aware-scan

end

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7) Enable fair access in the WLAN traffic management profile to provide fair delivery of the video streams to many different type of wireless clients like a, g, or n.

Example

To configure fair access for the WLAN traffic management profile named "default" to ap-group named "default" for 5 GHz wireless clients, issue the following commands:

config t

wlan traffic-management-profile "default"

shaping-policy fair-access

exit

ap-group default

dot11a-traffic-mgmt-profile "default"

end

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8) Enable band steering in the WLAN virtual AP profile if the SSID is being broadcasted to 2.4 GHz and 5 GHz RF bands. Band steering helps persuade dual-band wireless clients to associate to 5 GHz.

Example

To enable band steering on the "wlan virtual-ap CorpNet-vap_prof" Virtual AP, issue the following commands:

config t

wlan virtual-ap CorpNet-vap_prof

band-steering

end

write memory

These steps should provide the best quality video for wireless clients. Refer to the ArubaOS User and CLI Guide for further information on each configuration parameter.

Version history
Revision #:
1 of 1
Last update:
‎07-07-2014 11:58 AM
 
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