Configure a Mesh QoS Policy

About this task

Define a mesh QoS policy.

Excessive traffic can cause performance issues or bring down the network. Excessive traffic can be caused by network loops, faulty devices, or malicious software like a worm or virus that has infected one or more devices at the branch. By activating rate limiting, you can limit the maximum rate sent to or received from the wireless network (and mesh point) per neighbor. It prevents any single user from overwhelming the wireless network. It also provides differential service for service providers. You can set separate QoS rate limit configurations for data transmitted from the network and from a mesh point‘s neighbor back to their associated access point radios and managing controller or service platform.

Before you define rate limit thresholds for mesh point transmit and receive traffic, define the normal number of ARP, broadcast, multicast, and unknown unicast packets that typically transmit and receive from each supported WMM access category. If thresholds are defined too low, normal network traffic (required by end-user devices) is dropped, resulting in intermittent outages and performance problems.

A connected neighbor can also have QoS rate limit settings defined in both the transmit and receive direction.

Procedure

  1. Select Policies > Mesh > Mesh QoS.
  2. Select to create a new mesh QoS policy or to edit an existing policy.
    The Rate Limit dashboard opens.
  3. Configure the following parameters for the From Air Upstream Rate Limit, or traffic from the controller to associated access point radios and their associated neighbor:
    Mesh Tx Rate Limit Select to activate rate limiting for all data received from any mesh point in the mesh
    Rate Define a receive rate limit between 50 and 1,000,000 kbps. This limit constitutes a threshold for the maximum number of packets transmitted or received over the mesh point from all access categories. Traffic that exceeds the defined rate is dropped and a log message is generated. The default setting is 5,000 kbps.
    Maximum Burst Size Set a maximum burst size between 2 and 1,024K bytes. The smaller the burst, the less likely the transmit packet transmission will result in congestion for the mesh point‘s client destinations. By trending the typical number of ARP, broadcast, multicast, and unknown unicast packets over a period of time, the average rate for each access category can be obtained. Once a baseline is obtained, administrators should then add a 10% margin (minimally) to allow for traffic bursts at the site. The default burst size is 320K bytes.
  4. Set the following From Air Upstream Random Early Detection Threshold settings, for each access category:
    An early random drop occurs when a traffic stream falls below the set threshold.
    Background Traffic Set a percentage value for background traffic in the transmit direction. This is a percentage of the maximum burst size for low priority traffic. Background traffic exceeding the defined threshold is dropped and a log message is generated. Background traffic consumes the least bandwidth of any access category, so this value can be set to a lower value once a general transmit rate is known by the network administrator using a time trend analysis. The default threshold is 50%
    Best Effort Traffic Set a percentage value for best effort traffic in the transmit direction. This is a percentage of the maximum burst size for normal priority traffic. Best effort traffic exceeding the defined threshold is dropped and a log message is generated. Best effort traffic consumes little bandwidth, so this value can be set to a lower value once a general transmit rate is known by the network administrator using a time trend analysis. The default threshold is 50%.
    Video Traffic Set a percentage value for video traffic in the transmit direction. This is a percentage of the maximum burst size for video traffic. Video traffic exceeding the defined threshold is dropped and a log message is generated. Video traffic consumes significant bandwidth, so this value can be set to a higher value once a general transmit rate is known by the network administrator using a time trend analysis. The default threshold is 25%
    Voice Traffic Set a percentage value for voice traffic in the transmit direction. This is a percentage of the maximum burst size for voice traffic. Voice traffic exceeding the defined threshold is dropped and a log message is generated. Voice applications consume significant bandwidth, so this value can be set to a higher value once a general upstream rate is known by the network administrator using a time trend analysis. The default threshold is 0%
  5. Configure the following parameters for the To Air Downstream Rate Limit, or traffic from neighbors to associated access point radios and the controller or service platform:
    Mesh Rx Rate Limit Select to activate rate limiting for all data transmitted by the device to any mesh point in the mesh
    Rate Define a transmit rate limit between 50 and 1,000,000 kbps. This limit constitutes a threshold for the maximum number of packets transmitted or received over the mesh point (from all access categories). Traffic that exceeds the defined rate is dropped and a log message is generated. The default setting is 5,000 kbps
    Maximum Burst Size Set a maximum burst size between 2 and 1,024K bytes. The smaller the burst, the less likely the transmit packet transmission will result in congestion for the mesh point‘s wireless client destinations. By trending the typical number of ARP, broadcast, multicast, and unknown unicast packets over a period of time, the average rate for each access category can be obtained. Once a baseline is obtained, administrators should then add a 10% margin (minimally) to allow for traffic bursts at the site. The default burst size is 320K bytes
  6. Set the following To Air Downstream Random Early Detection Threshold settings, for each access category.
    An early random drop occurs when the number of tokens for a traffic stream falls below the set threshold.
    Background Traffic Set a percentage value for background traffic in the receive direction. This is a percentage of the maximum burst size for low priority traffic. Background traffic exceeding the defined threshold is dropped and a log message is generated. Background traffic consumes the least bandwidth of any access category, so this value can be set to a lower value once a general transmit rate is known by the network administrator using a time trend analysis. The default threshold is 50%
    Best Effort Traffic Set a percentage value for best effort traffic in the receive direction. This is a percentage of the maximum burst size for normal priority traffic. Best effort traffic exceeding the defined threshold is dropped and a log message is generated. Best effort traffic consumes little bandwidth, so this value can be set to a lower value once a general transmit rate is known by the network administrator using a time trend analysis. The default threshold is 50%
    Video Traffic Set a percentage value for video traffic in the receive direction. This is a percentage of the maximum burst size for video traffic. Video traffic exceeding the defined threshold is dropped and a log message is generated. Video traffic consumes significant bandwidth, so this value can be set to a higher value once a general transmit rate is known by the network administrator using a time trend analysis. The default threshold is 25%
    Voice Traffic Set a percentage value for voice traffic in the receive direction. This is a percentage of the maximum burst size for voice traffic. Voice traffic exceeding the defined threshold is dropped and a log message is generated. Voice applications consume significant bandwidth, so this value can be set to a higher value once a general upstream rate is known by the network administrator using a time trend analysis. The default threshold is 0%
  7. Configure the following settings for From Air Upstream Rate Limit in the Neighbor Settings field:
    Neighbor Rx Rate Limit Select to activate rate limiting for data transmitted from the client to its associated access point radio and connected controller or service platform. Enabling this option does not invoke client rate limiting for data traffic in the receive direction
    Rate Define a transmit rate limit between 50 and 1,000,000 kbps. This limit constitutes a threshold for the maximum number of packets transmitted or received from all access categories. Traffic that exceeds the defined rate is dropped and a log message is generated. The default setting is 1,000 kbps
    Maximum Burst Size Set a maximum burst size between 2 and 1,024K bytes. The smaller the burst, the less likely the transmit packet transmission will result in congestion for the wireless client. The default burst size is 320K bytes
  8. Configure the following settings for From Air Upstream Random Early Detection Threshold in the Neighbor Settings field:
    Background Traffic Set a percentage value for background traffic in the transmit direction. This is a percentage of the maximum burst size for low priority traffic. Background traffic exceeding the defined threshold is dropped and a log message is generated. The default threshold is 50%
    Best Effort Traffic Set a percentage value for best effort traffic in the transmit direction. This is a percentage of the maximum burst size for normal priority traffic. Best effort traffic exceeding the defined threshold is dropped and a log message is generated. The default threshold is 50%
    Video Traffic Set a percentage value for video traffic in the transmit direction. This is a percentage of the maximum burst size for video traffic. Video traffic exceeding the defined threshold is dropped and a log message is generated. The default threshold is 25%
    Voice Traffic Set a percentage value for voice traffic in the transmit direction. This is a percentage of the maximum burst size for voice traffic. Voice traffic exceeding the defined threshold is dropped and a log message is generated. The default threshold is 0%, which implies that no early random drops will occur
  9. Configure the following settings for To Air Downstream Rate Limit, or traffic from a controller or service platform to associated access point radios and the wireless client:
    Neighbor Tx Rate Limit Select to activate rate limiting for data transmitted from connected wireless clients. Enabling this option does not invoke rate limiting for data traffic in the transmit direction
    Rate Define a transmit rate limit between 50 and 1,000,000 kbps. This limit constitutes a threshold for the maximum number of packets transmitted or received by the client. Traffic that exceeds the defined rate is dropped and a log message is generated. The default setting is 1,000 kbps
    Maximum Burst Size Set a maximum burst size between 2 and 1,024K bytes. The smaller the burst, the less likely the receive packet transmission will result in congestion for the wireless client. The default burst size is 320K bytes
  10. Set the following To Air Downstream Random Early Detection Threshold settings for each access category:
    Background Traffic Set a percentage value for background traffic in the receive direction. This is a percentage of the maximum burst size for low priority traffic. Background traffic exceeding the defined threshold is dropped and a log message is generated. The default threshold is 50%
    Best Effort Traffic Set a percentage value for best effort traffic in the receive direction. This is a percentage of the maximum burst size for normal priority traffic. Best effort traffic exceeding the defined threshold is dropped and a log message is generated. The default threshold is 50%
    Video Traffic Set a percentage value for video traffic in the receive direction. This is a percentage of the maximum burst size for video traffic. Video traffic exceeding the defined threshold is dropped and a log message is generated. The default threshold is 25%
    Voice Traffic Set a percentage value for voice traffic in the receive direction. This is a percentage of the maximum burst size for voice traffic. Voice traffic exceeding the defined threshold is dropped and a log message is generated. The default threshold is 0%, which implies that no early random drops will occur
  11. Select Save to update this mesh QoS rate limit settings.
  12. Select Multimedia Optimizations.
  13. Set the following Accelerated Multicast settings:
    Disable Multicast Streaming Select to deactivate all multicast streaming on the mesh point.
    Automatically Detect Multicast Streams Select to have bridged multicast packets converted to unicast to provide better overall airtime utilization and performance. The administrator can either have the system automatically detect multicast streams and convert all detected multicast streams to unicast, or specify which multicast streams are to be converted to unicast. When the stream is converted and being queued up for transmission, a number of classification mechanisms can be applied to the stream. The administrator can choose from the following classification types: Trust, Voice, Video, Best Effort, and Background.
    Manually Configure Multicast Addresses Select and specify a list of multicast addresses and classifications. Packets are accelerated when the destination addresses matches.

    Select Add and specify a list of multicast addresses and classifications. Packets are accelerated when the destination addresses matches

  14. Select Save to update the Mesh Multimedia Optimizations settings.