Load balancing problem

[johannf]

Hi, we have 2 4402 controllers and WCS v.7.0.172. 1142 and 3502 AP's

Problem : 30-50 clients connects to one AP. Other AP's in the same room/area have only 3-6 clients connected.

How can I prevent this and probably get better performance.

I have disabled datarates from 0-11 Mbs.

Regards

Johann Folkestad

[Scott Fella]

There is a feature in the 7.x version that you can enable client load balancing per wlan ssid.  However, this feature has caused me issues in the past and is not really worth enabling unless you do a lot of testing.  If the users are not having issues, then I wouldn't worry about it, as the client is the one that chooses what ap it wants to join.

[Nigel Bowden]

It's a tricky one as the clients make the decision about who they are going to try to associate with.

You might try turning the power down on your APs to reduce cell sizes and encourage clients to use an AP that they can hear locally.

Nigel.

[johannf]

Good idea. I'll try this.

JF

[George Stefanick]

There is load balance on the controllers as Scott pointed out... Here is the reaosn why they dont work, ie "Reason Code 17".

Aggressive Load-Balancing

Aggressive load-balancing on the WLC allows the LAPs to load-balance wireless clients across APs in an LWAPP system.

This feature can be used in order to load-balance clients across LAPs on a single controller.

Aggressive load-balancing works at the association phase. If enabled  and the conditions to load-balance are met, when a wireless client  attempts to associate to a LAP, association response frames are sent to  the client with an 802.11 response packet that includes status code 17.  This code indicates that the AP is too busy to accept any more  associations.

It is the responsibility of the client to honor, process or discard  that association response frame with reason code 17. Some clients ignore  it, even though it is part of the 802.11 specification. The standard  dictates that the client driver must look for another AP to connect to  since it receives a "busy" message from the first AP it tries. Many  clients do not do this and send the association request again. The  client in question is allowed on to the wireless network upon subsequent  attempts to associate.

In WLC versions 6.0.182.0 and earlier, the controller only sends one  association response frame with reason code 17 to the client. If the  client decides to discard the reason code 17, the client can try the  same AP again and this time the AP allows the client to complete the  association.

If the client honors the association response status code 17, the  client then attempts to associate to a different AP. For example, if  load-balancing is enabled and the load-balancing window is configured as  five clients, when a sixth client tries to associate to the AP, the  client receives an 802.11 Association Response frame with status code  17, which indicates that the AP is busy.

[johannf]

Hmm, I found this settings in "Configure AP" - Performance Profile. Any idea if I can use this. Noting in the help file.

[Nigel Bowden]

They are just threshold settings that alter the levels at which profile thresholds are breached and alarms will be generated. They do not control client numbers on an AP.

Nigel.