Configures the rate limiting of traffic on a per meshpoint or per neighbor basis
Excessive traffic can cause performance issues or bring down the network entirely. Excessive traffic, bombardments and interference are caused by numerous sources, such as network loops, faulty devices, or malicious software (such as a worm or virus) that has infected one or more branch-level devices. Rate limiting limits the maximum rate sent to or received from the wireless network (and meshpoint) per neighbor. It prevents any single user from overwhelming the wireless network. It also provides differential service for service providers. An administrator can set separate QoS rate limit configurations for data transmitted from the network and data transmitted from a mesh point's neighbor.
Before defining rate limit thresholds for meshpoint transmit and receive traffic, it is recommended that you 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.
rate-limit [meshpoint|neighbor]
rate-limit [meshpoint|neighbor] [from-air|to-air] {max-burst-size <2-1024>|rate <50-1000000>}
rate-limit [meshpoint|neighbor] [from-air|to-air]
{red-threshold [background <0-100>|best-effort <0-100>|video <0-100>|voice <0-100>]}
rate-limit [meshpoint|neighbor] [from-air|to-air] {max-burst-size <2-1024>|rate <50-1000000>}
|
meshpoint |
Configures rate limit parameters for all data received from any meshpoint in the mesh network. This option is disabled by default. |
|
neighbor |
Configures rate limit parameters for neighboring meshpoint devices. Enables rate limiting for data transmitted from the client to its associated access point radio and connected controller. This option is disabled by default. |
|
from-air |
Configures rate limits for traffic from the wireless neighbor to the network. |
|
to-air |
Configures rate limits for traffic from the network to the wireless neighbor. |
|
max-burst-size <2-1024> |
Optional. Configures the maximum burst size in
kilobytes.
For a meshpoint: The smaller the burst, the less likely that the transmit packet transmission results in congestion for the meshpoint'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 320 kbytes. For a neighbor: The smaller the burst, the less likely the transmit packet transmission will result in congestion for the wireless client. The default burst size is 64 kbytes. |
|
rate <50-1000000> |
Optional. Defines a receive or transmit rate limit in
kilobytes per second
For a meshpoint: This limit constitutes a threshold for the maximum the number of packets transmitted or received over the meshpoint (from all access categories). Traffic that exceeds the defined rate is dropped and a log message is generated. The default setting is 5000 kbps. For a neighbor: This limit constitutes a threshold for the maximum the number of packets transmitted or received (from all access categories). Traffic that exceeds the defined rate is dropped by the client and a log message is generated. The default rate is 1,000 kbps. |
rate-limit [meshpoint|neighbor] [from-air|to-air]
{red-threshold [background <0-100>|best-effort <0-100>|video <0-100>|voice <0-100>]}
|
meshpoint |
Configures rate limit parameters for a meshpoint |
|
neighbor |
Configures rate limit parameters for neighboring meshpoint devices |
|
from-air |
Configures rate limits for traffic from the wireless neighbor to the network |
|
to-air |
Configures rate limits for traffic from the network to the wireless neighbor |
|
red-threshold |
Optional. Configures RED (random early detection) threshold for traffic class |
|
background <0-100> |
The following keyword is applicable to the ‘from-air‘
and ‘to-air‘ traffics.
For a meshpoint: 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%. For a neighbor: This is a percentage of the maximum burst size for low priority traffic. Background traffic exceeding the defined threshold is dropped by the client and a log message is generated. The default threshold is 50%. |
|
best-effort <0-100> |
The following keyword is applicable to the ‘from-air‘
and ‘to-air‘ traffics.
For a meshpoint: 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%. For a neighbor: This is a percentage of the maximum burst size for normal traffic. Best effort traffic exceeding the defined threshold is dropped by the client and a log message is generated. The default threshold is 50%. |
|
video <0-100> |
The following keyword is applicable to the ‘from-air‘
and ‘to-air‘ traffics.
For a meshpoint: 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%. For a neighbor: This is a percentage of the maximum burst size for video traffic. Video traffic exceeding the defined threshold is dropped by the client and a log message is generated. The default threshold is 25%. |
|
voice <0-100> |
The following keyword is applicable to the ‘from-air‘
and ‘to-air‘ traffics.
For a meshpoint: 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%. For a neighbor: This is a percentage of the maximum burst size for voice traffic. Voice traffic exceeding the defined threshold is dropped by the client and a log message is generated. The default threshold is 0% and implies no early random drops will occur. |
nx9500-6C8809(config-meshpoint-qos-test)#rate-limit meshpoint from-air max-burst-size 800
nx9500-6C8809(config-meshpoint-qos-test)#show context meshpoint-qos-policy test rate-limit meshpoint from-air max-burst-size 800 accelerated-multicast 224.0.0.1 classification video nx9500-6C8809(config-meshpoint-qos-test)#
nx9500-6C8809(config-meshpoint-qos-test)#rate-limit meshpoint from-air rate 80000
nx9500-6C8809(config-meshpoint-qos-test)#rate-limit meshpoint from-air red-threshold video 80
nx9500-6C8809(config-meshpoint-qos-test)#rate-limit meshpoint from-air red-threshold voice 70
nx9500-6C8809(config-meshpoint-qos-test)#show context meshpoint-qos-policy test rate-limit meshpoint from-air rate 80000 rate-limit meshpoint from-air max-burst-size 800 rate-limit meshpoint from-air red-threshold video 80 rate-limit meshpoint from-air red-threshold voice 70 accelerated-multicast 224.0.0.1 classification video nx9500-6C8809(config-meshpoint-qos-test)#
| no (meshpoint-qos-policy) |
Resets traffic rate limits for this meshpoint QoS policy |