For the nerds

In simple terms, GBEUPhone consists of:

a Mitel SIP-DECT system running the free-tier licence with 5 RFPs
Asterisk PBX
some Grandstream IP phones
a MikroTik hexS router
a simple Django web app with an Angular UI feeding into a sqlite file
a hand full of python scripts to sync the phone and user data to the various other systems
quite some network in between