Controller Based WLANs

Best Practices and Check list for Aruba WLAN Video Deployment

Wired Infrastructure

1. Make sure to utilize Gigabit Ethernet, end to end from Video server, Controller and along with 802.11n AP`s (or above).

      2. Enable IGMP

          IGMP proxy or IGMP snooping should be able to provide video delivery only to those AP`s with subscribers.

3. QOS Tagging & Traffic Prioritization

• Traffic Tagging and prioritization needs to enabled on wired network to provide QOS for Video Streams.
• Enable Layer 3 Video Differentiated Services Code Point (DSCP) tagging and Layer 2 802.1p tagging on the application (server and clients if possible), the controller and prioritization/QoS on the wired infrastructure for end-to-end QoS guarantees.

4. Recommendation and Adjustment of Frame Size

• Make sure to set the video server MTU low enough to avoid fragmentation or enable jumbo frames to the largest support size possible.
• Ensure MTU of video server is not larger than max frame size of any wired segment.
• Fragment loss results in the entire video frame being retransmitted, also increasing over the air bandwidth.

Aruba end

1. Understand Type of Deployment Campus, Remote AP, Type of forwarding mode Tunnel, Decrypt-Tunnel, Split Tunnel, or Bridge.

      2. Enable IGMP Snooping/Proxy.

• IGMP Snooping uses the WLAN controller to monitor the clients that are subscribed to multicast Video groups, and only sends multicast traffic to AP`s when required and also, only on a per-group basis
• Helps to identify which AP`s have clients that have subscribed to multicast streams, and then block replication of Mcast stream to other AP`s
• IGMP proxy implements multicast routing by re-originating IGMP joins and leaves from the source of the controller.
• IGMP proxy is enabled on the user VLAN IP interface, also stating the interface where the multicast frames are being transmitted into the controller and this will make sure that the IGMP client membership table is filled out properly.
• Without the IGMP client membership table properly filled out, dynamic multicast optimization will not take place, leading to video quality degradation

     3.  Enable DSCP,Traffic Tagging QOS and Optimization end to end

     4.  Enable DMO & Distributed DMO(D-DMO)

Note:

• DMO is dynamic, providing automatic multicast-to-unicast traffic optimization in the controller without requiring ongoing monitoring and configuration.
• Multicast IP frames are transmitted over the air using 802.11 unicast headers dynamically based on a configurable threshold.Enable Multicast Rate Optimization on Virtual-AP (VAP) profile.

     5.  WMM traffic shaping for Video (Allocate the percentage value based on the requirement and this is dedicated Video; you can provide 70% of air time fairness)

     6.  Enable Band steering on VAP profile (With client match this is taken care by over writing the steering from VAP profile)

     7.  Tweak RF (Radio power, Client match and Shaping policy)

     8.  Check list and few commands to troubleshoot on controller.

• Show ap active
• Show datapath session table (Do the video traffic getting prioritized)
• Show ap debug client-table ap-name (Client tx rates, retries etc)
• Show ap debug radio-stats ap-name (WMM video Queue stats, channel busy, Noise floor, etc.)
• Show ip igmp group
• Show ip igmp interface