Asterisk compatible hardware to support Siemens Optiset E


Does anyone know a hardware, which I can use in an asterisk BPX to support Siemens Optiset E phones?

I’m evaluating an idea now, wheater can replace an existing Siemens Hicom 300 by using an asterisk BPX. Currently there are arround 300 phones connected to the Hicom.
It would be very nice (and hopefully cheaper), if there is a meaningful way to reuse the Optiset E phones

Thanks for all ideas.