Solved: Best practices enterprise wifi

trondaker · ‎11-11-2016

Hi,

We have a pair og 8540s running HA/SSO. Currently controlling about 500 1832i/2702i in a large number of disperse buildings. The config is the same for all buildings, same SSIDs (about 6 now, hopefully this can be reduced to 3 in 2017). The questions is, how would you handle the 2.4/5 GHz problem? We use the band select feature on all SSIDs, but i still see that 1/3 (about 500) of our clients are connected using 2.4. When there are problems reported its usually clients connected to 2.4 GHz, with lots of interference and high channel util. Would it be best to have separate SSIDs for 2.4 and 5 gig? Is that "normal" in an enterprise network?

Also, the extended uni-channels, is it "safe" in 2016 to assume that clients connecting now support these channels - and if they dont, they are so old or obscure that we can safely ignore?

Third and lastly, there have been many discussions on this, but if we enable the extended uni channels, we could software upgrade and get the DBS-feature and enable "Best" channel width. Will there be any problems related to clients that does not support wider bandwidths connecting to an AP running say 80?

Greatful for input guys.

Freerk Terpstra · ‎11-12-2016

The client is always leading in the decision making which frequency band is going to be used. Besides enabling "band steering" there are a few more things which can be done to "steer" the client's behavior:

1. Verify that the coverage on the 802.11a/n/ac is just as good as on the 802.11b/g/n, preferable even better. Do this with a site survey and consider the weakest client. Note: while performing the site survey, also verify which 802.11b/g/n radios can be disabled to limit the co-channel interference as much as possible for the clients which really don't support 802.11a/n/ac.
2. Convince the purchase and IT departments within the company to only buy new equipment which supports 802.11a/n/ac.
3. Configure the client's driver to prefer 802.11a/n/ac if possible.
4. Make sure that all company owned and controlled clients use a decent wireless driver.

In my experience you can enable the UNII-2 and UNII-2 extended channels just fine. RRM will prefer the UNII-1 channels and use the higher channel only if it is needed (and no radar is detected on the channels of course). If you want to know more about which client supports which channels check out Mike Albano's website.

If individual clients really need the higher data-rates I would use 40Mhz channels, but in most deployments I still use 20Mhz channels and make sure that there are alternative access-points in the area to provide more capacity. I have only seen one topic regarding problems with clients which got confused by 40Mhz channels, so based on that amount you should be fine. For 80Mhz channels there is not enough spectrum available in my opinion. I have never worked with DBS feature myself, so I have no idea how effective and efficient it is.

Please rate useful posts... :-)

View solution in original post

Freerk Terpstra · ‎11-12-2016

The client is always leading in the decision making which frequency band is going to be used. Besides enabling "band steering" there are a few more things which can be done to "steer" the client's behavior:

1. Verify that the coverage on the 802.11a/n/ac is just as good as on the 802.11b/g/n, preferable even better. Do this with a site survey and consider the weakest client. Note: while performing the site survey, also verify which 802.11b/g/n radios can be disabled to limit the co-channel interference as much as possible for the clients which really don't support 802.11a/n/ac.
2. Convince the purchase and IT departments within the company to only buy new equipment which supports 802.11a/n/ac.
3. Configure the client's driver to prefer 802.11a/n/ac if possible.
4. Make sure that all company owned and controlled clients use a decent wireless driver.

In my experience you can enable the UNII-2 and UNII-2 extended channels just fine. RRM will prefer the UNII-1 channels and use the higher channel only if it is needed (and no radar is detected on the channels of course). If you want to know more about which client supports which channels check out Mike Albano's website.

If individual clients really need the higher data-rates I would use 40Mhz channels, but in most deployments I still use 20Mhz channels and make sure that there are alternative access-points in the area to provide more capacity. I have only seen one topic regarding problems with clients which got confused by 40Mhz channels, so based on that amount you should be fine. For 80Mhz channels there is not enough spectrum available in my opinion. I have never worked with DBS feature myself, so I have no idea how effective and efficient it is.

Please rate useful posts... :-)

trondaker · ‎11-14-2016

Thanks, just what i needed :)