This will build a container for FreePBX - A Voice over IP Manager for Asterisk. Upon starting this image it will give you a turn-key PBX system for SIP calling.
FreePBX is the most widely-used open source IP PBX in the world. An intuitive graphical user interface makes taking advantage of the power of Asterisk much easier to deploy and use.
With remote-working + social distancing likely through the next 18-24 months, this can be used to a) enable dial-in audio-only participation in upcoming Cloudron Jitsi install, and b) host large HD-quality audio conferences.