Install isdnvbox by entering the following commands in the terminal:
sudo apt update sudo apt install isdnvbox
Description:
ISDN utilities - answering machine dependency package
Let your Debian system be your answering machine! Messages can be accessed remotely, automatically emailed, etc. . This package depends for convenience on both the vbox server (with which the messages are recorded) and the client (with which you listen to them).
Homepage: https://www.isdn4linux.de
Version: 1:3.25+dfsg1-9ubuntu2
Section: universe/utils