An IP PBX (Internet Protocol Private Automatic Branch Exchange) is a modern business communication system that uses the internet (IP) to route calls instead of traditional phone lines, acting as a digital switchboard to manage internal and external communication for an organization.

Guestroom phones are still needed in hotels for safety, ease of use (especially for older guests/emergencies), and reliable service requests (room service, wake-up calls), though their form is evolving into more integrated, IP-based, or smart devices to complement mobile tech, meeting needs for guests who prefer simple, direct communication or lack mobile service.