Hamshack Hotline was a free dedicated Voice over IP (VoIP) phone system dedicated to serving and supporting amateur radio. It was very easy to set up, and inexpensive surplus phones are easily sourced from sites such as e-Bay. The system was shut down on August 29, 2025.
Other VoIP systems are available to the ham community. One system is AmateurWire, and signing up to use the service is easy. I have recieved my AmateurWire account and will connect to the server after updating my hamshack.