Pivot,
Clientmatch is being hardened in the 4.2.x.x code, which was just released recently. I would say to use the version of clientmatch that is in that train of code, because alot of things have been improved.
With that being said, the majority of clientmatch parameters are rarely changed from the defaults.
Here are your definitions:
- CM Calculating Interval - How often should I consider bandsteering or load-balancing clients. Anything lower than 30 seconds could possibly speed up how fast clients are steered and load balanced, but could increase cpu with little benefit.
- CM Neighbor Matching percent is used for load balancing users. 75 means that 75% of the access points that can be viewed by another access point shares its RF domain, so a client can be load balanced among those access points.
- CM Threshold - If an access point in the same RF domain has "CM Threshold" above another access point in the same RF domain, clients will be sent to another access point. It could be seen as the difference between an access point and the least loaded AP in the RF domain before clients are sent elsewhere.
- SLB Mode - Are we load balancing clients based on how many are on a channel, how many are on a specific radio or both?
You have to be careful, because ClientMatch is different between the Instant (IAP) and Controller-based (AOS) platforms, so you can get confused if you read the explanations for both at the same time. Also, ClientMatch has recently been "hardenend" in the 4.2.0.0 release of Instant, so that is probably the version you want to test it out on. Typically the default parameters are not changed unless TAC says to, because it requires a full understanding to (1) understand what the knobs do and (2) to understand if changing them is getting you close to your result.
Based on your changed parameters:
- Anything under the 30 seconds for the CM calculating interval could cause higher CPU and it should not be changed:
- CM Neighbor matching should not be changed because increasing it to 90 percent means that you are increasing the possible APs in an RF domain, which means clients can be load balanced to access points that are out of their actual RF domain.
- Setting a CM threshold of 30 means the difference between the least populated and most populated clients in an RF domain must differ by 30 before load balancing would start.
Long story short, just stick with the defaults and you should be fine.
Background spectrum monitoring is normally turned on if you have issues and you need to see if there is any non-wifi interference. Typically you would leave this off in regular production to save any overhead. It does not work in conjunction with clientmatch, no.