Weak Signal Probe Request Suppression does not work?

[andreas_brueck]

Hello everybody,

we have some trouble with sticky clients which does not roam to a better access point. Because of that i activated the option Weak Signal Probe Request Suppression for my 2,4 and 5 Ghz radio profiles.

After that i did a complete configuration update on all access points. Two days later i checked the connected clients for some access points and i found clients with really poor SNR values.

How is it possible? Is it correct that clients with a poor SNR still will be connected to an not optimal access point? Maybe i don't understand this option correctly.

We are using the on-premises Hivemanager NG (build version 19.5.1.7-NGVA ) and a lot of AP230 (HiveOS 10.0r5 build-228634 ).

Thank you in advance.

Regards,

Andreas Brück

[andreas_brueck]

Hello Brian, hello Sam,

thanks for your explanation and your suggestions. I already configured the data rates to 12 mbit/s for all SSIDs before i activated the SNR probe suppression, but just for 802.11 b/g and a.

What is about the 802.11n standard? Make it sense to deactivate some MCS rate Settings?

I found also a option under "Monitor --> Devices --> Choose an access point --> Edit --> Additional Device Settings --> Neighboring Devices --> Roaming Threshold" which is set to High. Is it necessary to set this threshold to Medium or Low?

[samantha_lynn]

The weak SNR probe suppression should be dropping the weaker signals, you might want to open a case so we can investigate that further, but for clients that aren't connecting to the best AP I would recommend adjusting lower data rates rather than the weak SNR probe response setting.

If you disable the lower data rates on your SSIDs, this will require a stronger connection between the AP and the client device. That will mean that the client device needs to be closer to the AP before connecting/roaming. Not only will this reduce the chances of unintentional roaming, but it will also reduce the distance the packets need to travel, which will also reduce collision and interference on your network.

To disable the lower data rates we need to go to Configure> Network Policies> Select the network policy> Open the SSID> Expand Additional Settings> Customize Optional Settings (at the end of the page)>In the 2.4 GHz 11/bg Rate Setting section, we want to turn 1Mbps-9Mbps to N/A. In the 5.0 GHz 11a Rate Setting section we want to turn 6 Mbps and 9 Mbps to N/A. You'll need to update the APs again to use these new settings, but a delta update should be fine for these changes so you don't need to reboot your AP.

[bpowers]

Andreas,

That feature only works for the initial association/authentication attempt or when a device chooses to roam.

A probe request is intended to do a couple things. Mainly gather a list of neighbor APs for when a device chooses to roam. They are also used to gather a list of APs to associate too.

So once a client is associated to the WLAN if it moves away from it's associated AP, and chooses not to roam, this feature will not help. But once it does choose to roam, this feature will limit the number of APs that will send a Probe Response after the station sends out the Probe Requests.

If you're looking to help users roam to different APs, you might benefit from altering the mandatory and optional data rates for the 2.4/5 GHz bands for the SSID(s) you use. As if they are default, then the client devices can stay associated to an AP so long as it's frames can be decoded at 1 Mbps on 2.4 GHz and 6 Mbps on 5 GHz. The below image depicts this somewhat. In this regard, you must have at least one data rate set as Mandatory. This is the minimum needed to stay connected to an AP. Some folks like using 12 Mbps. I've seen sites where all rates are disabled below 24 Mbps. YMMV and if it were me, I'd make incremental adjustments to this to better understand how your client devices act with such a change. I also wouldn't use any rates other than 6, 12 or 24 as the mandatory rate even though you can as those are the 3 rates per the 802.11 standard that should be mandatory rates.