Configuring Traffic Policing

Context

To protect network resources and prevent network congestion, configure traffic policing to limit the rate of traffic entering the WLAN.

Traffic policing on a WLAN can be configured in a traffic profile or user profile.

Monitored Object	Description	Command
SSID-based QoS CAR	If the QoS CAR in an SSID profile is set to car-value, the total bandwidth of all the STAs associating with all the VAPs with this SSID profile bound does not exceed car-value.	qos car (SSID profile view)
Rate limiting for a single VAP	If the rate limit in a traffic profile is set to limit, the total bandwidth of all the STAs associating with a single VAP with this SSID profile bound does not exceed limit.	rate-limit vap { up \| down } rate-value
Rate limiting for a single STA	Static rate limiting: If the rate limit in a traffic profile is set to limit, the bandwidth of a single STA with a VAP with this SSID profile bound does not exceed limit. Dynamic rate limiting: After dynamic rate limiting is enabled, the device determines whether to perform three-phase rate limiting for wireless users depending on whether the air interface is congested. This improves network experience of wireless users. For the implementation of dynamic rate limiting, see Implementation of Dynamic Rate Limiting. If static rate limiting has been enabled, static rate limiting takes precedence over dynamic rate limiting.	Static rate limiting: rate-limit client { up \| down } rate-value Dynamic rate limiting: rate-limit client dynamic disable and rate-limit client dynamic rate-value

Monitored Object

Description

Command

SSID-based QoS CAR

If the QoS CAR in an SSID profile is set to car-value, the total bandwidth of all the STAs associating with all the VAPs with this SSID profile bound does not exceed car-value.

qos car (SSID profile view)

Rate limiting for a single VAP

If the rate limit in a traffic profile is set to limit, the total bandwidth of all the STAs associating with a single VAP with this SSID profile bound does not exceed limit.

rate-limit vap { up | down } rate-value

Rate limiting for a single STA

Static rate limiting: If the rate limit in a traffic profile is set to limit, the bandwidth of a single STA with a VAP with this SSID profile bound does not exceed limit.
Dynamic rate limiting:
After dynamic rate limiting is enabled, the device determines whether to perform three-phase rate limiting for wireless users depending on whether the air interface is congested. This improves network experience of wireless users.

For the implementation of dynamic rate limiting, see Implementation of Dynamic Rate Limiting.

If static rate limiting has been enabled, static rate limiting takes precedence over dynamic rate limiting.

Static rate limiting: rate-limit client { up | down } rate-value
Dynamic rate limiting: rate-limit client dynamic disable and rate-limit client dynamic rate-value

Dynamic rate limiting is implemented as follows:

The system calculates the channel usage periodically (every 2 seconds). Assume that the lower limit in a traffic profile is set to limit, the three-phase rate limits are limit (phase-1 rate limit), limit/2 (phase-2 rate limit), and 2×limit (phase-3 rate limit).

Check whether the air interface is congested as follows:

If the channel usage is higher than 80% for five consecutive periods (10s), the air interface is congested.
If the channel usage is lower than 70% for 30 consecutive periods (1 minute), the congestion of the air interface is eliminated.

The following figure illustrates transition of the three-phase rate limiting states.

Figure 1 Dynamic rate limiting

Pre-configuration Tasks

Before configuring traffic policing, perform the task of WLAN Service Configuration Guide.

Procedure

Configure traffic policing in a traffic profile.
1. Run system-view
  The system view is displayed.
2. Run wlan
  The WLAN view is displayed.
3. Run traffic-profile name profile-name
  A traffic profile is created and the traffic profile view is displayed.
4. Run rate-limit { client | vap } { up | down } rate-value
  The rate limit is configured for upstream and downstream traffic of all STAs or a single STA on a VAP.
  - By default, the rate limit for upstream and downstream traffic of all STAs on a VAP is 4294967295 kbit/s.
  - By default, the rate limit for upstream and downstream traffic of a single STA on a VAP is 4294967295 kbit/s.
  The rate limit configured for each STA on a VAP does not take effect for multicast packets.
5. Run undo rate-limit client dynamic disable
  Dynamic rate limiting is enabled for a single STA in a VAP.
  
  By default, dynamic rate limiting is enabled for a single STA in a VAP.
6. Run rate-limit client dynamic rate-value
  The dynamic rate limit threshold is set for a single STA in a VAP.
  
  By default, the dynamic rate limit threshold of a single STA in a VAP is 16 Mbit/s.
7. Run quit
  Exit from the traffic profile view.
8. Run vap-profile name profile-name
  The VAP profile view is displayed.
9. Run traffic-profile profile-name
  A traffic profile is bound to the VAP profile.
  
  By default, the traffic profile default is bound to a VAP profile.
Configure traffic policing in an SSID profile.

QoS CAR parameters configured in an SSID profile are valid only when the service data forwarding mode is set to tunnel forwarding.

When a user is configured as a VIP user, the QoS CAR configured in the SSID profile does not take effect.
1. Run system-view
  The system view is displayed.
2. Run wlan
  The WLAN view is displayed.
3. Run ssid-profile name profile-name
  The SSID profile view is displayed.
4. Run qos car inbound cir cir-value [ cbs cbs-value [ pbs pbs-value ] | pir pir-value [ cbs cbs-value pbs pbs-value ] ]
  QoS CAR parameters are configured.
  
  By default, no QoS CAR parameters are configured in an SSID profile.

Verifying the Configuration

Run the display traffic-profile { all | name profile-name } command to check the configuration of the rate limit for upstream and downstream traffic of the STAs on the VAP in the traffic profile.
Run the display ssid-profile { all | name profile-name } command to check QoS CAR parameter settings in the SSID profile.