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WLC Channel Selection - All APs crowded on one 2.4Ghz channel

Hello,

I am investigating poor performance of a Cisco wireless network and think the issue may be caused by channel interferance from other accesspoints not controlled by my WLC. I have a 2504 and two 2600 series APs in an open plan office, I also have a standalone AP that the WLCs are replacing. (once all the testing is done all clients will move off this AP and it will be added to the WLC as a lightweight AP). What I am seeing is high latency and poor speeds on this wireless network despite only 2-3 laptops connected and 5-6 smartphones. When I look at a Wifi channel analyser on my phone I can see all the APs are using channel 1. even though the Channel is already very crowded the WLC does not change channels automaticallly. I have checeked the settings under wireless->802.11b/g/n and wirelesse->802.11a/n and the DCA is using its default settings. I have changed the TPC version to v2 which is

Interference Optimal Mode but this has made no change.

Half of the channels are free yet all wireless networks are crowded on channels 1-3... I would have expected the WLC to move itself away from this channel and use the uncrowded channel 11.

When I look at the 5Ghz radios I can see that one is on channel 40 and another on channel 48, I am not sure how crowded these channels are as my phone and laptop are 2.5Ghz only. but at least it has moved them to seperate channels to avoid interferance.

The WLC APs are about 10-15 meters apart from each other with no walls in between. Has anyone else seen issues like this and has anyone any suggestions to fix the issue?

WLC 2504 running 7.4.100.0

Gerry

3 REPLIES
Hall of Fame Super Silver

Re: WLC Channel Selection - All APs crowded on one 2.4Ghz channe

Don't use TPCv2... change it back to TPCv1. Is this how your DCA is setup:

Sent from Cisco Technical Support iPhone App

-Scott
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Hall of Fame Super Silver

Re: WLC Channel Selection - All APs crowded on one 2.4Ghz channe

One other thing is its not a good idea to have a mixed environment. Meaning having lightweight and autonomous. Roaming would be an issue so just keep that in mind.

Sent from Cisco Technical Support iPhone App

-Scott
*** Please rate helpful posts ***
New Member

WLC Channel Selection - All APs crowded on one 2.4Ghz channel

Hi,

I had actually modified the DCA settings today to try and force it to do something. I had checeked all four boxes and set the sensitivity to high. This made no difference to the channel setting with both APs still on channel 1. I then manually moved the AP to channel 11 and it did switch. unfortunalty this didnt resolve my problem of poor performance and really high ping times. I am seeing around 500ms in pinging a local device.

Is the channel issue a red herring for the performance issues? this worked fine when it was installed about a month ago and nothing has been added to the environment in terms of radio frequency.

I will be adding the autonomous AP to the controller as soon as I have fixed this issue. Clients who are connected to the autonomous AP are getting much better results and this is located centrally in the office. the two WLC APs are equidistant from it.

Any ideas?

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