What Is VoIP?

VoIP — Voice over Internet Protocol — is technology that transmits phone calls as digital data packets over the internet, rather than through traditional circuit-switched telephone networks. While VoIP has enabled legitimate innovations in business communications, it is simultaneously the primary technical infrastructure enabling the robocall epidemic: by eliminating the per-call cost structure of traditional telephony, VoIP enables operators to place millions of calls per hour at near-zero cost, from anywhere in the world.

Why VoIP Changed the Robocall Equation

Traditional telephone networks required physical infrastructure investment tied to geographic locations, making high-volume calling operations expensive and traceable. A call originating from a specific PSTN (Public Switched Telephone Network) switch was geographically and organizationally attributable.

VoIP eliminated both constraints. A robocall operator can:

• Place millions of calls per day from a single internet connection at a cost of fractions of a cent per call
• Spoof the outgoing Caller ID to display any phone number, regardless of actual location or network affiliation
• Route calls through multiple international VoIP gateways to obscure the originating infrastructure
• Operate from any jurisdiction globally, making US regulatory enforcement difficult or impossible

VoIP and STIR/SHAKEN

The STIR/SHAKEN framework was specifically designed to address VoIP-enabled caller ID spoofing. By requiring originating carriers to cryptographically sign call identity, STIR/SHAKEN creates an attribution chain for calls that remain within the US carrier network. The enforcement gap — calls originating from offshore VoIP infrastructure entering US networks at gateway points — has led the FCC to continue expanding STIR/SHAKEN requirements to international gateway carriers in its 2026 framework updates.