Back up the card first. These downloads write a complete bootable image and replace the target card contents.
VKLink for Raspberry Pi 3 / 3B+
Current legacy production image. 563 MB
VKLink for Raspberry Pi 2
Archived image for existing Pi 2 installations. 431 MB
Next-generation VKLink
Debian, current Asterisk and support for Pi 3 through Pi 5 are in field testing. Tester builds are not production releases.