SIP trunking provides connectivity between voice systems and telephone networks using SIP protocol over internet connections. It replaces traditional phone lines with virtual connections that can scale dynamically.
How does SIP trunking work?
A SIP trunk provider connects your voice infrastructure to the PSTN through their network. Calls route over the internet to the provider, who handles interconnection with telephone carriers. You pay for capacity and usage rather than maintaining physical lines. Multiple simultaneous calls share the same trunk.
Why does SIP trunking matter?
SIP trunking is how voice AI platforms connect to the telephone network cost-effectively. It enables geographic flexibility (phone numbers anywhere), rapid scaling (add capacity instantly), and integration with cloud infrastructure. Without SIP trunking, voice AI would require expensive traditional phone infrastructure.
SIP trunking in practice
A business deploys a voice AI agent and needs phone numbers in 10 cities. Through SIP trunking, they provision numbers in each location without physical presence. All calls route to their cloud-based AI platform. When volume increases in one city, they add capacity immediately without hardware changes.