Connection speed of Wireless client is too low.

[eeebbunee]

Hello Professionals,

I got a user complaint about low quality of wireless(PDA), and when I check the connection status I got:

Compared with other PDA which is connected same AP, connection speed is 72Mbps.

What might cause the differences? Which configuration change make this better?

Connection speed 9Mbps is weird result cause from my controller config, 9 Mbps is disabled. (12 Mbps mandatory.)

Should it be guaranteed at least 12Mbps?

Furthermore, what if I set the data rates for 2.4GHz having 12 and 24 mandatory and rest of them will be supported.
Is this not recommended? 

Thank you..

[Flavio Miranda · Accepted solution]

@eeebbunee 

 Mandatory data rates is for cell acceptance but it does not mean that after the client is onboard it can not work in different speed, even close to zero.

 The signal quality is very good, which means, in my opinion this is not a problema related to wifi. As you mentioned that you have other device with so much better performance, I would ask to check this device. Maybe upgrade or compare the config with the good one.

"Furthermore, what if I set the data rates for 2.4GHz having 12 and 24 mandatory and rest of them will be supported.
Is this not recommended? "

As I said, this data rates is for device on board and is not a minimum speed supported. When the Access Points receive the beacon from the device, it will check if those data rates are supported and if not the device will not be accepted.  But, once the device is connected  If the device is not able to handle 12 Mbps and had to reduce the speed, it can slow dow up to close to zero.

[Leo Laohoo]

That screenshot is the AP/WLC asking the wireless client "what are you capable of doing".  

72 Mbps is nothing.  That value is just what the wireless NIC of the wireless client is capable of doing.  It may say "72 Mbps" but most of the time wireless client do not have the capabilities to process 72 Mbps of traffic continuously without the melting the CPU.

[Rich R]

1. Make sure your Cisco AP/WLC software is up to date as per TAC recommended link below

2. If the service works fine with other devices then it is probably a device problem, so make sure device, OS and drivers are up to date.

[JPavonM]

Check the same device connected to other AP and or channel, it may be a faulty firmware, chipset or radio interface in the client device.