topic Re: Wireless I/O graph-- What this pattern means? Why consistent timeo in Wireless

Wireless I/O graph-- What this pattern means? Why consistent timeouts?

jonathan.maxwell — Sun, 22 May 2022 12:03:09 GMT

Hello.

Please see 2 images attaches-- I/O graph, and pcap.

QUESTIONS:

1. What does this specific pattern in this wireless I/O Graph represent?

2. Why does wireless device exchange no packets for approximately 1.5 seconds in a repeating pattern?

Any helpful input is appreciated.

Additional information: This may not be relevant to the graph (because after research I expect the symptom is a documented bug involving Apple security protocol implementation.): Client is experiencing symptom that only Apple vendor devices are being randomly disconnected from 1st SSID of multiple SSID wireless network.

WLC= C9800-40-K9, AP= C9120

I look forward to your input. Thank you.

Re: Wireless I/O graph-- What this pattern means? Why consistent timeo

MHM Cisco World — Sun, 22 May 2022 12:04:23 GMT

if only APPLE then there is high chance that you need enable Fast transition.
https://www.cisco.com/c/dam/en/us/td/docs/wireless/controller/technotes/80211r-ft/b-80211r-dg.html

Re: Wireless I/O graph-- What this pattern means? Why consistent timeo

Ambuj M — Sun, 22 May 2022 14:59:16 GMT

This does seem like a buggy behavior, this can not be contention, time is too long, if you have QOS enabled and high number of devices using wireless medium preferably then it’s possible to see such pattern but again 1.5 sec seem to long and I am not sure you are using 802.11e heavily.
what’s the effect of this ? Are you seeing degraded performance on these devices ?

have you compared the graph with any other non-apple device ?

Re: Wireless I/O graph-- What this pattern means? Why consistent timeo

Rich R — Mon, 23 May 2022 13:48:42 GMT

What version of software is your 9800-40 running?

Re: Wireless I/O graph-- What this pattern means? Why consistent timeo

Arshad Safrulla — Mon, 23 May 2022 15:35:58 GMT

How PCAP was done?