Only with Mikrotik I have witnessed this. I have a Mikrotik AP with 28 Clients Associated. Some of them are B-Only Units. When I switch to B/G on the AP, and manually-select G Data Rates not to exceed 18Mbps, only 12 Clients are able to re-connect. This is only when using Mikrotik as the Access Point. Any ideas? Does this need to be another fix for the next firmware release?

I am using 3.30. Just retuned my network again, getting CCQ over 90% with everyone by setting the data rates. It has not been a problem for me.

i think B only clients will not support more than 11mbps. Why has the data rate been fixed to 18 mbps?

I'm sorry maybe I did not describe the problem correctly. The B-Only Clients will not associate back to the Access Point, even though the AP is set to B/G, with fixed G Rates unchecked 54,48, and 36. Supported B Rates are still set at 1,2,5.5, and 11, yet no B-Only client returns to the AP when the G rates are modified.

The reason I don't allow more than 18Mbps on G-Band is because the AP will sometimes put someone at a high rate and the throughput/CCQ goes to crap.

I have actually seen a very similar problem, but with N - and a lesser extent G (sorry I dont have any B only devices) . If you click the default rates radio button, it all works fine, but if you manually specify rates, devices over lower capability can not connect.

For example, I clicked every rate possible, both supported and basic, but N devices that only supported MCS 0-7 were unable to connect. Devices that supported the full range up to MCS 15 still could. The issue was still there when only selecting MCS 7 and MCS 15. Additionally, specifying these rates stopped all G only devices (despite all generic A/B/G rates being set, and the point being set to B/G/N).

Clicking that default radio button did fix it all though.

Bug?

I'd say a bug indeed. How would we contact Mikrotik on getting this fixed? I'm forced to use Ubiquiti gear for now...