Hi,
I'm from Extricom support.
The EXSW-2400 is not compatible with the EXRP-22n AP. You would need a MultiSeries500 or 1000 switch to work with these along with a suitable port licence. You can still purchase the EXRP-20 AP's if you need to add some in a new area or coverage gap. With Software for the EXRP-22n the newer switches are not backward compatible with the EXRP-20 and in any case a mixture of AP families is not supported across any platform.
If you have any issues you can email support - see the web site for address details - and you will always get a response.
Regards
Jez