You can configure link latency on the controller to measure the link between an access point and the controller. This feature
can be used with all access points joined to the controller but is especially useful for FlexConnect and OfficeExtend access
points, for which the link could be a slow or unreliable WAN connection.
The following are some guidelines for link latency:
Link latency monitors the round-trip time of the CAPWAP heartbeat packets (echo request and response) from the access point
to the controller and back. This time can vary due to the network link speed and controller processing loads. The access point
timestamps the outgoing echo requests to the controller and the echo responses received from the controller. The access point
sends this delta time to the controller as the system round-trip time. The access point sends heartbeat packets to the controller
at a default interval of 30 seconds.
Link latency calculates the CAPWAP response time between the access point and the controller. It does not measure network
latency or ping responses.
The controller displays the current round-trip time as well as a running minimum and maximum round-trip time. The minimum
and maximum times continue to run as long as the controller is up or can be cleared and allowed to restart.
You can configure link latency for a specific access point using the controller GUI or CLI or for all access points joined
to the controller using the CLI.
This section contains the following subsections: