Clients joining B Radio

[Koevi Vong]

Hi,

I am having an issue where clients are joining the B Radio instead of A/G.

I have even disabled 11mbs and below data rates under the B/G/N radio section and set the SSID to A/G Only but clients are still joining the B Radio.

Currently running a Virtual WLC version 7.3.101.0

Has anyone come across this issue or know a fix?

Thanks

[stamper.brian]

Some of these questions will be elementary:

1.  The B radio is the same physical radio as the G radio (2.4 GHz).  If you have clients joining at 802.11b rather than 802.11G/A/N the clients are still joining the 2.4 GHz radio.  By setting the ssid to A/G only you would not be essentially shutting off 802.11b all together so it would be impossible for the clients to join  that wlan at  802.11b.  Are you sure the AP's in question are joined to the controller your making the change on?  Are they joining that particular SSID or is there another one they are jumping to?  Just some quick "simple" questions.

[Koevi Vong]

Hi Brian,

Thanks for your reply. All the AP's are currently registered to the WLC, there is currently only one SSID configured at the moment.

The AP model is Cisco 2602i

[stamper.brian]

Can you attach a screnshot of the configuration on the WLAN showing a/g only and the client page showing the clients registering 802.11b?

[Koevi Vong]

[stamper.brian]

I can't see the whole picture for some reason but it would appear these clients are joining 2.4Ghz 802.11bn.  If you go look at the "details" of a specific client listed as b/n I think you'll see rates above 54Mbps?

[Koevi Vong]

Yes, the clients are on B/N with high data rates above 54mbps.

B Radio uses different coding from what i remember so I'd prefer them to join A/G/N. I've double checked the settings but for osme reason the clients still choose B Radio.

[stamper.brian · Accepted solution]

You are correct about the b using dsss and g using ofdm.  However, your clients are connecting at n.  Why the gui states bn rather than gn I'm not sure.  Here is a link to another post almost identical to your question here.

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&ved=0CDIQFjAA&url=https://supportforums.cisco.com/thread/2121326&ei=70XzUMSmConWqAHp0YGwDQ&usg=AFQjCNHTIbHH8BhFVrCyBUoPL4ymrIHYHQ&sig2=lQBCAomYDOoh95oksA5QtA&bvm=bv.1357700187,d....

[Koevi Vong]

Thanks, I will have a read and see what I can find.

I am also having issues with clients dropping out but not sure if thats related to the B Radio

[Koevi Vong]

Would upgrading the devices wireless driver be worth while to do?

[stamper.brian]

Its always a good thing to have them on current or near current driver versions.  Again I think the fact that the client is connected at 802.11bn is really just telling you its n data rates.  So still using OFDM and not causing any issues with protect as if there were 802.11b DSSS clients.  As far as the clients dropping I'd assume that was another issue and starting with that client driver can't hurt to test. If its happening frequently an output of a debug client while it happens would be a good place to start.

[Koevi Vong]

Oh ok, so basically B/N is the same as G/N? and they work exactly the same?

B Radio = DSSS

G Radio= OFDM

B/N & G/N = MIMO

is this right?

[stamper.brian]

Kind of. 

802.11n uses OFDM just like a/g but makes use of mimo and other features to achieve higher data rates.  Good quick read article on that here:

http://www.techrepublic.com/blog/wireless/what-is-the-big-deal-about-80211n/160

[Scott Fella]

Koevi,

You will not see a 802.11gn when you are looking at the Monitor Cleints tab. If you have 802.11b clients, they will show up there as 802.11b. 

Thanks,

Scott

Help out other by using the rating system and marking answered questions as "Answered"

[Koevi Vong]

Hi Scott,

So your saying G/N clients would be shown as B/N?

Would the B/N Clients be using OFDM/MIMO modulation? and not DSSS which B radio uses?

I have disabled 11mbps data rates and below.

Thanks