cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
3703
Views
6
Helpful
4
Replies

DNAC: Understanding high channel utilization

SondreSandberg
Level 3
Level 3

I'm looking at high channel utilization issues in DNAC (v. 2.2.3.6) from an 9120i connected to a 9800 v.17.3.4c
Seeing high channel utilization, low interference and low tx/rx utilization from the AP.

Is it correct that there is some other 802.11 device on the same channel as the AP causing high utilization?
I interpret interference as all RF that is not 802.11 traffic, is that correct?

SondreSandberg_0-1666359997363.png

SondreSandberg_1-1666360016036.png

 

4 Replies 4

Rich R
VIP
VIP

Yes that sounds about right to me

------------------------------
Please click Helpful if this post helped you and Accept as Solution (drop down menu at top right of this reply) if this answered your query.
------------------------------
TAC recommended codes for AireOS WLC's   and   TAC recommended codes for 9800 WLC's
Best Practices for AireOS WLC's,   Best Practices for 9800 WLC's   and   Cisco Wireless compatibility matrix
Check your 9800 WLC config with Wireless Config Analyzer using "show tech wireless" output or "config paging disable" then "show run-config" output on AireOS and use Wireless Debug Analyzer to analyze your WLC client debugs
Field Notice: FN63942 APs and WLCs Fail to Create CAPWAP Connections Due to Certificate Expiration
Field Notice: FN72424 Later Versions of WiFi 6 APs Fail to Join WLC - Software Upgrade Required
Field Notice: FN72524 IOS APs stuck in downloading state after 4 Dec 2022 due to Certificate Expired
- Fixed in 8.10.196.0, latest 9800 releases, 8.5.182.12 (8.5.182.13 for 3504) and 8.5.182.109 (IRCM, 8.5.182.111 for 3504)
Field Notice: FN70479 AP Fails to Join or Joins with 1 Radio due to Country Mismatch, RMA needed
Field Notice: FN74383 APs Running 17.12.4/5/6/6a May Run Out of Flash Space Preventing Upgrades
How to avoid boot loop due to corrupted image on Wave 2 and Catalyst 11ax Access Points (CSCvx32806)
Field Notice: FN74035 - Wave2 APs DFS May Not Detect Radar After Channel Availability Check Time
Leo's list of bugs affecting 2800/3800/4800/1560 APs
Default AP console baud rate from 17.12.x is 115200 - introduced by CSCwe88390

jonathga94
Level 4
Level 4

You are correct that interference can come from any wireless signal that the access point (AP) cannot understand. In your report, I see some peaks of high channel utilization, which suggests that the AP may be surrounded by other WiFi networks that are using the available airtime. This can cause problems for your WiFi devices when they try to communicate with the AP.

arya
Frequent Visitor
Frequent Visitor

Any workaround of this issue?

I have this problem too

JPavonM
VIP Alumni
VIP Alumni

This could be anything from a high bandwith load to a random non-WiFi interference, it all depend is the peaks are only on a given channel or not. If the AP is always operating at the same channel, then this is likely to be high load utilization (on nearby APs). If it is on the same channel, it is unlikely that the source or interference will be something in transit, like vehicles jamming devices (like those from embassies or military ones), but who knows.

If this is a repetitive issue you may need to investigate it locally with an spectrum analyzer to see if this interference source is something you can detect, locate and mitigate, or avoid it moving AP to a different channel otherwise. But don't forget to look for high load devices on the area.

Review Cisco Networking for a $25 gift card