SIP trunking is a modern communication method that uses the internet (VoIP) to replace traditional phone lines, letting businesses make and receive calls and multimedia (voice, video, text) over a single data connection. It connects a business's Private Branch Exchange (PBX) system to the Public Switched Telephone Network (PSTN) virtually, offering cost savings, scalability, and unified communications by consolidating services onto one IP network. 

The analog PBX (Private Branch Exchange) market still exists, but it is in its "sunset years" and rapidly declining in favor of IP-based and cloud solutions. While new installations are rare, a, lingering market remains for maintenance, support, and specialized use cases. 

Analog telephone sets are still relevant for specific business applications in 2026, primarily due to their extreme reliability during power outages and their suitability for specialized, low-tech functions. While many businesses have transitioned to Voice over Internet Protocol (VoIP) for advanced features and cost savings, analog, or Plain Old Telephone Service (POTS), remains crucial in sectors requiring high security or in locations with poor internet connectivity.