topic Re: Reached Buffer limit in Access Points - Indoor and Outdoor

Reached Buffer limit

farzan_qureshi_ — Fri, 13 Dec 2019 05:47:29 GMT

Hi there,

We are using H510s at a customer site. I see following in the AP syslog:

Dec 13 05:10:12 kern.warn kernel: [84170.752918] Reached buffer limit
Dec 13 05:10:12 kern.warn kernel: [84170.755246] Reached buffer limit
Dec 13 05:10:12 kern.warn kernel: [84170.757607] Reached buffer limit
Dec 13 05:10:12 kern.warn kernel: [84170.763184] Reached buffer limit
Dec 13 05:10:12 kern.warn kernel: [84170.765507] Reached buffer limit
Dec 13 05:10:12 kern.warn kernel: [84170.767782] Reached buffer limit

Following is the version command output:

Ruckus H510 Multimedia Hotzone Wireless AP
Version: 5.1.1.0.624

The APs are managed by Vsz 5.1.1.0.5985.1.0

Any ideas what may be the reason? We are getting complaints from the users that they are not able to associate to AP.

Re: Reached Buffer limit

sanjay_kumar — Fri, 13 Dec 2019 08:28:41 GMT

Hi Farzan,

Seems like the AP memory might be getting full.

Is this happening for all the H510 APs?
Is the AP configuration getting updated? Click on the AP and check for the "Configuration Status".

Download the AP support file and check the "Device Info" for CPU and Memory information.

Re: Reached Buffer limit

michael_brado — Fri, 13 Dec 2019 17:04:31 GMT

Is this AP in a high density environment? How many clients on the AP when you see this?

Re: Reached Buffer limit

farzan_qureshi_ — Sun, 15 Dec 2019 23:28:01 GMT

Hi Sanjay,
Yes we see it on all H510s in the environment.

The configuration is getting updated. I will check the device info and report back.

Re: Reached Buffer limit

farzan_qureshi_ — Sun, 15 Dec 2019 23:29:08 GMT

Hi Michael,
No, it is not. There are only a handful of users on the APs say 4 to 6.

Re: Reached Buffer limit

farzan_qureshi_ — Mon, 16 Dec 2019 00:07:16 GMT

The CPU usage is sitting at 0%

CPU : 0.00%
Load : 0.07 0.08 0.09 1/127 4145
Memory : 225420 KB (free), 7712 KB (cache) 233132 KB (available) 470460 KB (total)

This is when only one client connected and I still see this message in the logs

kern.warn kernel: [1551239.199465] Reached buffer limit

Re: Reached Buffer limit

paul_johnson — Thu, 24 Jun 2021 17:13:21 GMT

Any update or findings on this? We are seeing the same in the logs on low density R500/R510 installs. 5-15 clients max.

kern.warn kernel: [84170.765507] Reached buffer limit

Re: Reached Buffer limit

paul_johnson — Thu, 24 Jun 2021 17:15:19 GMT

Also see this a lot;

Priority: emerg
Tag: syslog
Message: upgrade_debug: pid=27614, get_ap_list(): ap-list found !!

Re: Reached Buffer limit

farzan_qureshi_ — Thu, 24 Jun 2021 23:02:13 GMT

@paul_johnson

What firmware version are the APs on?

Re: Reached Buffer limit

paul_johnson — Fri, 25 Jun 2021 02:51:12 GMT

They were on ZD awhile back but now several are on latest unleashed R500 200.7 in a separate area.

Re: Reached Buffer limit

farzan_qureshi_ — Fri, 25 Jun 2021 03:38:48 GMT

So for us it got resolved when we moved from version 5.1 to 5.2. We don't see any buffer overflow errors. I am not sure about Unleashed version. It they are already on latest version then nothing that you can do other than log it with Ruckus Support.

Re: Reached Buffer limit

paul_johnson — Fri, 25 Jun 2021 03:50:02 GMT

This seems to be the pattern of logs;

kernel: ol_rc_update_handler: WARNING: handler called without transmit attempts

wifi0: 63661671 : stuck beacon (missed 3) scanning 0, syncbeacon 0, sc_beacons 1,sc_isCaldone: 1

12:18:11 ZD-APMgr: IPC_thread rcv ping from TACMON
12:17:56 kernel: Reached buffer limit
12:17:56 syslog: bba: STAs from 2.4g to 5g.
12:17:56 syslog: bba: sta-2g=6 sta-5g=1 perc=50 sta-2g-expect=3

11:17:56 kernel: Reached buffer limit
11:17:56 syslog: bba: STAs from 2.4g to 5g.
11:17:56 syslog: bba: sta-2g=6 sta-5g=3 perc=50 sta-2g-expect=4

Re: Reached Buffer limit

syamantakomer — Fri, 25 Jun 2021 14:06:45 GMT

Hi Paul,

Is there any service impact of this?

Re: Reached Buffer limit

paul_johnson — Fri, 25 Jun 2021 16:14:09 GMT

There are service impacts at the site and we are trying to narrow down the cause, we are not certain this has anything to do with it but buffer limit reached and stuck beacons stood out in the logs.

Clients complain of service degradation, two VPN users complain throughout the day performance gets worse and very slow speed (daily traffic about 400-700mb each of these two clients) . Also intermittent iPhone "unable to connect to network" with correct credentials and good RSSI.

5-15 clients max, load and band balancing is off

Re: Reached Buffer limit

farzan_qureshi_ — Tue, 29 Jun 2021 23:41:24 GMT

With iPhones, they have introduced random mac address feature. Try to disable it and then see how it goes.

Also, disable RSSI threshold if you have enabled on the APs where a device should be able to communicate with RSSI of -67 or something stronger to get a response from the AP.

Also, if you have 80 Mhz channels enabled, please decrease the bw to 40 Mhz channel or even 20 Mhz if the data requirements are not that high. Honestly, 20 Mhz will serve the purpose well and client devices will have stable connection health. However, placement of APs also matter.

I am sure you have already checked for the channel overlap in the premises.

Also, if channel fly is enabled, please move to background scanning and increase the scan interval to 3600sec.

Let us know how it goes.

Re: Reached Buffer limit

syamantakomer — Fri, 02 Jul 2021 14:15:05 GMT

Hi @paul_johnson ,

I do not think this log is relevant to any of the service impact you are facing.

I would suggest open a case with RUCKUS support and share all the information you have related to the actual service impact and what clients are facing.