It's hard to know . Previously, I had things set up so that one SSID offered the G radio and another SSID offered A radio. So, most folks would see the stronger signal on the G side and would connect to that SSID. If that wasn't desirable, then I would lower the power on the G radio at that location. Even so, the majority of connections (90 to 95%) were to the G side. I have since implemented band steering and I am now seeing from 25 to 35% of connections to the A radio. So FWIW, that's up from the 5 to 10% that folks were connecting to prior to steering.
I'm hoping that as newer clients come into play (and I roll out more sensitive 3040 APs), that this percentage will increase. But I too wonder how much steering is really affecting things .
Just a thought, but your clients may NOT be capable of 5G usage, or your devices may be too far apart (signal-wise) for those that have 5G to transfer to the next device. Typically if there is no (at least small) overlap in the radio signal, a transfer attempt would most likely be dropped losing the wifi connection completely.
You may have already seen it, but the DynamicSteering in vWLAN documentation can help you determine if bandsteering is working for you. There a few major details you have to consider. Like Michael said, the client has to be dual-band. Also, the channel utilization has to be considered. In vWLAN 2.9 you can see that from the AP details. If channel utilization is high on the 5 GHz radio, then clients might actually get downsteered. Keep in mind that utilization does not have to mean lots of associated clients. It could mean lots of co-channel interference or contention. You also have to be aware of steering safety mechanisms. A lot of steering mechanisms work by simply ignoring a client on a certain band. However, we can't do that indefinitely as some clients may never be able to associate. So if a client is behaving poorly and will only try the 2.4 GHz radio, then eventually the safety mechanisms kick in and the client is allowed on the network on the 2.4 GHz band.
With all of this in mind, you can start to determine if bandsteering is working in the methods our products allow.
If a dual-band client probes on both bands and the channel utilization is high, then the AP will not respond to probes or association requests on the overloaded band.
Idle Post-Association Steering
The AP looks at uplink signal strength from the dual-band client and decides whether to upsteer or downsteer. The legacy approach is sort of brute force by effectively refusing to respond to the client. If the client supports 802.11v, then the AP can much more gracefully help the client steer to the correct band.
Active Post-Association Steering
The dual band client must support 802.11k and 802.11v. These protocols provide mechanisms by which the AP can gracefully steer a client to the correct band.
So you have to be aware of two main things. If client supports 802.11k and/or 802.11v, then bandsteering is more effective. If the dual-band clients do not support those standards, then bandsteering is only as effective as you allow it to be. By that I mean that bandsteering is not a solution for poor channel and power plans. You can try our DynamicRF feature to help get you moving in the right direction, or you can seek out wireless professionals in your area to perform on-site surveys. If you use our DynamicRF algorithm, make sure you set reasonable upper limits on TX power. I would recommend no more than 25 mW (14 dBM) on the 5 GHz radio and 10 mW (10 dBm) on the 2.4 GHz radios to start with. You can tweak power up or down from there, but just know that if you're already relying on max TX power for coverage, then you probably need to consider adding a few additional APs. This will reduce your individual BSAs and provide a better client experience overall.
And just to be fair, bandsteering is a new feature. If you read this information and still feel like it's not working as you expected, then open up a ticket with our support team so they look into AP and determine if something else is going on.