Configuring Link Latency

Restrictions for Link Latency

  • Link latency is supported for use only with FlexConnect access points in connected mode. FlexConnect access points in standalone mode are not supported.

Configuring Link Latency (GUI)

Procedure

Step 1

Choose Wireless > Access Points > All APs to open the All APs page.

Step 2

Click the name of the access point for which you want to configure link latency.
Step 3

Choose the Advanced tab to open the All APs > Details for (Advanced) page.

Step 4

Select the Enable Link Latency check box to enable link latency for this access point or unselect it to prevent the access point from sending the round-trip time to the controller after every echo response is received. The default value is unselected.

Step 5

Click Apply to commit your changes.

Step 6

Click Save Configuration to save your changes.

Step 7

When the All APs page reappears, click the name of the access point again.
Step 8

When the All APs > Details for page reappears, choose the Advanced tab again. The link latency and data latency results appear below the Enable Link Latency check box:

  • Current—The current round-trip time (in milliseconds) of CAPWAP heartbeat packets or data packets from the access point to the controller and back.

  • Minimum—Since link latency has been enabled or reset, the minimum round-trip time (in milliseconds) of CAPWAP heartbeat packets or data packets from the access point to the controller and back.

  • Maximum—Since link latency has been enabled or reset, the maximum round-trip time (in milliseconds) of CAPWAP heartbeat packets or data packets from the access point to the controller and back.

Step 9

To clear the current, minimum, and maximum link latency and data latency statistics on the controller for this access point, click Reset Link Latency.

Step 10

After the page refreshes and the All APs > Details for page reappears, choose the Advanced tab. The updated statistics appear in the Minimum and Maximum text boxes.

Configuring Link Latency (CLI)

Procedure

Step 1

Enable or disable link latency for a specific access point or for all access points currently associated to the controller by entering this command:

config ap link-latency {enable | disable} {Cisco_AP | all}

The default value is disabled.

Note 

The config ap link-latency {enable | disable} all command enables or disables link latency only for access points that are currently joined to the controller. It does not apply to access points that join in the future.

Step 2

See the link latency results for a specific access point by entering this command:

show ap config general Cisco_AP

Information similar to the following appears:


Cisco AP Identifier.............................. 1
Cisco AP Name.................................... AP1
...
AP Link Latency.................................. Enabled
 Current Delay................................... 1 ms
 Maximum Delay................................... 1 ms
 Minimum Delay................................... 1 ms
 Last updated (based on AP Up Time)........... 0 days, 05 h 03 m 25 s


The output of this command contains the following link latency results:

  • Current Delay—The current round-trip time (in milliseconds) of CAPWAP heartbeat packets from the access point to the controller and back.

  • Maximum Delay—Since link latency has been enabled or reset, the maximum round-trip time (in milliseconds) of CAPWAP heartbeat packets from the access point to the controller and back.

  • Minimum Delay—Since link latency has been enabled or reset, the minimum round-trip time (in milliseconds) of CAPWAP heartbeat packets from the access point to the controller and back.

Step 3

Clear the current, minimum, and maximum link latency statistics on the controller for a specific access point by entering this command:

config ap link-latency reset Cisco_AP

Step 4

See the results of the reset by entering this command:

show ap config general Cisco_AP