A demonstration of two IP phones on separate AREDN networks talking to each other with direct IP dialing. All of this is running on battery power.
Parts:
Cisco SPA504G Phones
https://www.amazon.com/Cisco-SPA504G-Display-Certified-Refurbished/dp/B01K72RIXW/
TP-Link CPE-210
https://www.amazon.com/TP-Link-CPE210-300Mbps-dual-polarized-directional/dp/B00P4JKQGK
POE batteries
https://www.amazon.com/gp/product/B07PHQNLFY/
USB to power port cable
https://www.amazon.com/gp/product/B07WFKPKF9/