Reverse engineering a Viking VOIP phone protocol with Claude Code — Boris Starkov, Eleven Labs
May 29, 2026 · 20:11
Boris Starkov from ElevenLabs used Claude Code to reverse engineer the undocumented protocol of a Viking VOIP phone that three senior engineers and ChatGPT failed to configure in a year. Claude brute-forced all 676 possible two-letter command combinations, found 80 valid ones, then set up a TCP proxy between a Windows XP virtual machine and the phone to intercept traffic from the proprietary software. The critical missing piece—a one-byte checksum in the persistence command—was deduced by Claude by running known input-output pairs through the derived formula, confirming a simple subtraction. Starkov acted as Claude's hands, physically rebooting the phone and reporting beeps. The protocol is now open-sourced as a Claude Code skill, enabling direct programming without Windows software. The project culminated in a red phone booth at AI Engineer Europe where picking up the receiver connects to a Michael Caine voice agent quizzing attendees on British AI history.
