Frequent wireless disconnections occurring since upgrade to 10.21.01.0065

[Steve_Ballantyn]

I apologize for the redundant question. It seems like "clients disconnecting" is a common topic. But I am starting a new one, because it seems that every situation is different.

I have a C5210 and a bunch of 3825i AP's all over my hospital. Just before Christmas I upgraded to the latest firmware, 10.21.01.0065. Since then I am getting complaints from users (across the board) that they are frequently getting dropped from WiFi. After it happens they are easily able to reconnect and all is well. But it's driving them mad as they will be in mid-sentence documenting in their various applications and then it sort of freezes up and KAPOW! Connection lost!

There is nothing newer to upgrade to. And I suppose I could downgrade to see if the problems goes away. But I would rather seek out the source of the problem and fix it. Especially if it's just something wacky in my configuration.

I plan on putting in a call and opening a ticket on Monday morning with support. But in the meantime - does anyone have any ideas for me? I use Netsight and Purview, and I have all of these logs and diagnostic data at my disposal, but I am not really sure where to start. I suppose the first question is - does anyone else have this issue with this firmware?

[Steve_Ballantyn]

First off - thanks for all of this advice!

I have no idea what any of these settings are, so I trust you know a lot more than me when it comes to this stuff! Since I had to look them up, I figured I would paste it here from the documentation for the sake of discussion.

DTIM
Type the desired DTIM (Delivery Traffic Indication Message) period — the number of beacon intervals between two DTIM beacons. To ensure the best client power savings, use a large number. Use a small number to minimize broadcast and multicast delay. The default value is 5.

Aggregate MSDUs
Determines MAC Service Data Unit (MSDU) aggregation. Enable to increase the maximum frame transmission size.

Aggregate MPDUs
Determines MAC Protocol Data Unit (MPDU) aggregation. Enable to increase the maximum frame transmission size.

LDPC
Increases the reliability of the transmission resulting in a 2dB increased performance compared to traditional 11n coding.

Monitor Mode
An alarm is triggered and an information log is generated.
Active Mode
An alarm is triggered, an information log is generated, the AP stops operating on the current channel, and ACS automatically selects an alternate channel for the AP to operate on.

Protection Types
CTS
CTS (Clear to Send) Only.
RTS (Request to Send) and CTS
Recommended when a 40 MHz or 80 MHz channel is used. This protects high throughput transmissions on extension channels from interference from non-11n APs and clients.

Question - when you said to check the high use of air, which report was that? When I run the Wireless Statistics by Wireless APs I am seeing a lot of failures. Here is a screenshot ...

[Ronald_Dvorak]

You'd use multi-edit...

Set the checkmark on the APs (only APs from the same series i.e. 38xx in my example) and click on the Action button and choose multi-edit....

[Ronald_Dvorak]

no need to feel that way - the first time I was .. what the heck they removed multi-edit, should I change the config of 1000 APs one by one 🙂

took me a while to find the option

[Steve_Ballantyn]

I see it now. I feel stupid. I was looking under the Radio 1 and Radio 2 actions drop-downs. Well, nice to know where to find that because I might be applying those settings to another 70 access points!

[Ronald_Dvorak]

Hey Steve,

here what I currently use as standard setting...

- I set the basic rate to 24Mb if the AP coverage allows it = dense deployment
- radio#2 g/n, protection mode none for 11g = I don't support any 802.11b clients
- disabled on the WLAN service = 802.11k, FT, MFP

Could you tell whether the issues is on 2.4Ghz or 5GHz ?