Wireless Access

Hi,

 

One of customers is experiencing the problem with his wireless.

 

This customer has lots of Aruba 205’s, which we understand support 30-35 clients. Any more than this we see issues with stable client connectivity.

 

They broadcast two SSIDs from each AP. There is a private SSID secured with a WPA key and is only used for domain laptops. The public SSID is used with their NAC appliance (Bradford – network sentry) to allow staff, student and guests to register.

 

What we find is that in certain areas a teacher can walk into a classroom with their domain laptop and they are either unable to get on the WiFi or it is so slow it’s unusable.

 

When we investigate the AP will have lots of student devices connected many of which are no actually accessing the network and in the case of Android devices it appears they will connect to our public SSID and stay connected even if they aren’t registered with Bradford, they just sit there as a rogue device. What we want to solve is to somehow guarantee that staff connecting their domain laptops to SSID “TC-Private” get a usable experience at all times.

 

Any ideas that you could give us on this please?

 

Many Thanks,

What version of AribaOS is this? If you have support, you should open a case in parallel, because the resolution of this could be complicated.

Thanks for your reply.

 

The version is 6.4.3.4. I will also open a TAC case, but would like to work with the "community" to see if others have seen this problem.

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@danger wrote:

Thanks for your reply.

 

The version is 6.4.3.4. I will also open a TAC case, but would like to work with the "community" to see if others have seen this problem.

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Danger,

 

There are plenty of reasons for slowness:

 

- Broadcast filtering not turned on

- AP power too high, so clients hang on too long and consume airtime constantly retransmitting.  This hurts all clients that are on that access point, due to one client hanging on

- Too many dual-band clients ending up on the 2.4ghz band.  This is typically because the 2.4ghz spectrum propagates further than the 5ghz band at the same power.  Typically you would keep the max tx power of the 2.4ghz band 3 to 6 db lower than the 5ghz band to prevent this

- To many "fly bys" users who are just passing by but their devices are configured to automatically associate to an open SSID.  You could configure the local probe request threshold parameter on the SSID profile under advanced for your public network to 20.  That would mean the AP would only answer clients that it could see at 20 RSSI or stronger; eliminating alot of far away clients.

 

I can guess more, but opening a case would reveal if there is anything else like system issues, APs not negotiating the proper speed and duplex, etc...

For the Public SSID, you can decrease idle timeout values to kick inactive users out of the network after certain period of inactivity.

 

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@Jibran wrote:

For the Public SSID, you can decrease idle timeout values to kick inactive users out of the network after certain period of inactivity.

 

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Clients that are kicked off due to the idle timeout will just reassociate if they are still around.  Users who are in the user table but not around are not consuming any RF resources, except maybe for an ip address...