Cisco SD2008T-NA Configuration Manual page 236

Performing a Link Test
With the CCX link test, the controller can also test the link quality in the access point-to-client direction.
The controller issues link-test requests to the client, and the client records the RF parameters [received
signal strength indicator (RSSI), signal-to-noise ratio (SNR), etc.] of the received request packet in the
response packet. Both the link-test requestor and responder roles are implemented on the access point
and controller. Therefore, not only can the access point or controller initiate a link test to a CCX v4
client, but a CCX v4 client can initiate a link test to the access point or controller.
The controller shows these link-quality metrics for CCX link tests in both directions (out: access point
to client; in: client to access point):
Signal strength in the form of RSSI (minimum, maximum, and average)
•
Signal quality in the form of SNR (minimum, maximum, and average)
•
Total number of packets that are retried
•
Maximum retry count for a single packet
•
Number of lost packets
•
Data rate of a successfully transmitted packet
•
The controller shows this metric regardless of direction:
Link test request/reply round-trip time (minimum, maximum, and average)
•
The 4.0 release of controller software supports CCX versions 1 through 4. CCX support is enabled
automatically for every WLAN on the controller and cannot be disabled. The controller stores the CCX
version of the client in its client database and uses it to limit the features for this client. If a client does
not support CCX v4, the controller performs a ping link test on the client. If a client supports CCX v4,
the controller performs a CCX link test on the client. If a client times out during a CCX link test, the
controller switches to the ping link test automatically. See the
section on page 6-19
Note CCX is not supported on the AP1030.
Follow the instructions in this section to perform a link test using either the GUI or the CLI.
Cisco Wireless LAN Controller Configuration Guide
7-28
for more information on CCX.
Chapter 7 Controlling Lightweight Access Points
"Configuring Quality of Service Profiles"
OL-9141-03