MSM422: how to prevent users from connecting to Radio 2 when Radio 1 is in reach?

[Maxxx]

Hi,

It would be very very nice if someone could help me out with this problem:

I have one MSM422 configured to provide 802.11n (5Ghz) on radio 1 and on second radio 802.11g.

Radio 2 is for legacy clients.
I configured two SSIDs exclusively for each radio (SSID1 for 5Ghz, SSID2 for 2,4Ghz). All clients that are capable of n in 5Ghz mode don't have the Network for SSID2 configured to prevent them from connecting to the slower 2,4Ghz radio.

This of course does work.

But since 5Ghz radios don't penetrate walls et.c. as good as 2,4Ghz there's one room in the building which isn't covered by radio 1, but radio 2 only.

This room isn't used often, but 2 times a week it would be good to have wlan access there.

To achieve that I'd have to configure those clients for SSID2 also or configure a VSC to include both radios.

Of course they would automatically roam to Radio2 when they get into that room.
But how can I achieve that those clients will switch back from Radio 2 to Radio 1 as soon as Radio 1 becomes available again?

As I understand they'd stay on Radio2 since signal strength for Radio2 won't drop but get even better too as they approach the AP and radio1 would be available again.

Is there ANY way to solve that problem other than installing another 5Ghz Radio AP in this room?

Thank you very much!

Max

[Fred! · Accepted solution]

Hello Max,

Unfortunately this is not an easy problem to fix. It is the client that currently decides where to go based on any proprietary algorithms that client vendors (intel, broadcom, etc) will decide. Therefore not matter what you do, you don't have control over what is going to happen. Deploying another 5GHz radio might help because then the client may see a stronger signal with more speed available and "stick" to the 5GHz band, but you have not guarantee.

Right now, the APs have no way to decide intelligently where to redirect users. 802.11k is a standard that will/may help to achieve this, but unfortunately, not a lot of clients support 11k today nor does the MSM APs.

As the standard matures and as vendors will adopt it, this will likely be addressed.

[Maxxx]

Thank you very much fred for your competent answer!


So I guess I have no other option as to deploy another one.

Thanks again!

[Matt Marcos]

Try the other way. We represent the SAME SSID across both radios. (same as you pure 5GHZ N and legacy G). As fred states, it's the client that does it all.

If your clients are windows 7 there is a lot more controll now through group policy for wifi. You can have one group of machines just "not see" the SSID that you are advertising. This is only an OS thing though, any regular wifi scanner will show the SSID is actually transmitting...
You can also have a preffered list in a priority order through this GPO. this can help as well I reakon.

cheers,

Matt.

[Maxxx]

Thank you very much for the info, this is very interesting. Just a pity that most of our users are still on XP ;)

Nonetheless it's nice to know that some helping features exist already even without 802.11k.