SSID disappering for sometime and for some device

[PeeraPothikul]

In our office have 23 AP  combine with

21 units for  MR33   and

  4 units for  MR74. 

and configure to have 4 SSID.  all AP is configure RX-SOP to allow at -65 dbm (for roaming purpose)   and configure to use auto channel.

Our Problem

While Tablet (using windows 10 as OS )working for a while , SSID were disapper  (All SSID disspear from available list)  and need to wait  2-3 minutes to recovery by automatically. but It's not disappear for all device at the same time. even the location that Tablet face the problem is in the WIFI network range.

Let example.
Tablet01 face the issue of disapper but tablet02 is working fine without problem. (2 tablet using at same or very close location)..

I can't identify cause from WIFI controller or  Client device itself.

I try to see the event log of for the client and not understand . The log say only  802.11 disassociation for a while then association

Please guide me , 

Thank you.

 

[kYutobi]

If there are many more devices connecting fine besides the "one" tablet then I would look at the client device itself.

[PeeraPothikul]

Dear Kyutobi

Thank you for your reply ,  I also want to thinking about that but it's not occur only one client device .
More device face this issue too.

Is it possible ?  this problem might related to  WIFI channel  or Radio frequently or  WIFI load balancing  ?

Thank you 

Peera Pothikul

[NolanHerring]

whoa whoa whoa back it up beep beep beep

RX-SOP set to -65? Your shooting off your own foot

Do NOT do that

RX-SOP is the most powerful tool a Jedi can have, and if you don't know how to use it you will cause chaos.

RX-SOP is going to break your roaming, it does nothing to help it. Either turn it off, or dial it way back to -85ish (-80 at most).

Update your intel drivers

Report back

[NolanHerring]

To provide some feedback as well on the RX-SOP feature.

RX-SOP will only affect downlink, not uplink. So clients do not change, only the AP will 'act' differently. It will basically make it so that any packet it hears at the threshold you set (or weaker) it will ignore it and not waste any time on it. So it will help downlink throughput, potentially by a large amount especially in HD enviornments.

However, if you are setting the threshold too strong (like -65) its going to have a huge impact. Say you walk away from the AP with a laptop and a cellphone, by the time you get 30 feet away, the AP is going to start hearing the cellphone at -66 and then start ignoring its packets. The cell phone will now hard drop. The laptop wireless card has more power, so he might go another 20 feet before he gets 'dropped'. This will happen often and the clients will never be able to roam to another AP based on their algorithm.

To them, all they will 'see' is that the wireless isn't responding (even though they can still hear the AP just fine) and so they will end up retrying over and over. Eventually they will give up, and some phones might even blacklist your SSID because of too many failures to connect etc., but this is after probably like 10 seconds of a client being able to do nothing (which in wireless is an eternity).

Because of this hard wall your creating (which is a variable unique to each client), you'll want to be VERY careful with this tool. You'll be safe with -90, probably -85. Anything stronger you'll want to test clients with, walk around, make sure they are not getting clipped etc. You might be able to get to -80 but beyond that your rolling the dice in my opinion.


Here is some literature on the subject if you want to really learn more:

https://www.youtube.com/watch?v=QzZVo2PaBxU

https://documentation.meraki.com/MR/Radio_Settings/Receive_Start_of_Packet_(RX-SOP)

https://wjcomms.co.uk/2014/09/01/working-with-rx-sop-in-a-high-density-network/

https://www.youtube.com/watch?v=p5nx4L3RIVk&t=

http://nostringsattachedshow.com/RXSOP/Cisco_RXSOP.pdf

[PeeraPothikul]

Dear NolanHerring 

Oh oh... Thank you so much for RX-SOP setting. I changed to -85 dbm

The problem of HHT  is  HHT  try to connect the old AP and did not change to new AP even new AP is stronger signal. That why I set to -65..

HHT (HHT Denso) old device equipment (2.4 Ghz)  is not good function of roaming in Mezzanine environment (WH)  .   

from 2 months HHT is no problem but laptop and Tablet always come with the error disconnect while use APP like a realtime connection.

 .

Do you have any recommend for 5 Ghz , which value is recommend ?

Thank you so much

[NolanHerring]

There is no real recommended value for RX-SOP because its 100% dependent on 'your' environment. The issue is that your trying to use it to force clients to roam which isn't going to work.

Clients are the sole decision maker when it comes to roaming. This means that you need to make sure that your wireless coverage (cells) is adequate so that when they start walking away from one AP to another, there is enough overlap that by the time the signal gets low enough on the client, he will see the next AP and roam to it.

Best way to control that is with power level settings, and antenna (directional for example).

[Bossnine]

This alone makes me not want to mess with this option too much. 🙂

[NolanHerring]

Exactly !

If you are not sure what your doing then please don't use 😃