PSTN (Public Switched Telephone Network) is the traditional circuit-switched telephone infrastructure connecting landlines and mobile phones worldwide. Voice AI systems typically connect to the PSTN to make and receive standard phone calls.
How does voice AI connect to PSTN?
Voice AI platforms typically use SIP trunking to bridge between internet-based systems and the PSTN. When a caller dials a phone number, the call routes through the PSTN to the provider’s SIP infrastructure, which connects it to the AI voice agent over the internet.
Why does PSTN connectivity matter?
Despite growth in internet-based communication, the PSTN remains how most voice calls happen. Businesses need phone numbers that customers can dial from any phone. PSTN connectivity ensures voice AI can reach and be reached by anyone with a telephone, regardless of their technology.
PSTN in practice
A business deploys an AI voice agent with a local phone number. Customers dial this number from landlines, mobile phones, or VoIP systems. The calls route through various carriers and the PSTN, ultimately reaching the AI platform. From the customer’s perspective, it is simply a phone call requiring no special technology.