Cisco Access points and Motorola devices MC75A?

[John.Blackford1]

We have recently been carrying out some test with several Cisco Access points deployed at an airport and MC75A Motorola ruggedized devices We were investigating strange behavior of the devices not roaming to the best access points but to a very far one with about -80 dBm signal (even though there was one with -45 dBm nearby)On closer investigation we observed that for some access point types the devices could not connect even though a pc with the same SSID configured could connect with no problems. The following was observed for the Cisco access points using a Motorola MC75A device: Cisco AP MC75A connection CAP2702I-E Not OK in 5GHz BUT OK With 2.4 GHz CAP2602E Not OK in 5GHz BUT OK With 2.4GHz CAP2702E OK in 5GHz CAP2602I OK in 5GHz LAP1131AG OK in 5GHz: AND OK With 2.4 GHz Is this a known issue ? And if so are there any solutions to resolve this incompatibility?

[Freerk Terpstra]

The client is always leading in the roaming process, no matter how good the alternatives are or what extra information is being provided from the infrastructure side. My advice is that you check the wireless settings (roaming parameters) on the Motorola device. There should only be one wireless profile on the device which is configured identical as possible with the infrastructure side. So if your deployment is optimized for 802.11a/n/ac for example let the client only use those frequencies as well. Another thing to look into on the infrastructure side are the configured data-rates which may cause the client to "stick" to a sub-optimal access-point as well.

It depends on the country where you are, but because you are especially testing at an airport there is a change that you run into DFS issues as well. Make sure that if you use 802.11a/n/ac the used channels on the WLC match with the Motorola device as well and that there are no DFS hits.

If you checked all of the things above and you are sure that the RF part is fine as well (site survey), you should check the software version on the device and the controller. Also the output of an "debug client MAC" may give a clue for further troubleshooting.

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