Reverse engineering a Viking VOIP phone protocol with Claude Code — Boris Starkov, Eleven Labs

TL;DR

• 1

  Claude Code cracked hardware Boris couldn’t — Boris says he’s “just a normal software engineer,” but Claude handled the protocol discovery, checksum reversal, and orchestration that made the Viking phone usable again.

• 2

  The real blocker was persistence, not connectivity — Finding the phone’s command port and valid two-letter commands was manageable; the hard part was figuring out how settings were actually saved to long-term memory after reboot.

• 3

  A Windows VM became a sniffing tool, not the final solution — Because the vendor software only ran on Windows, Claude set up a Mac TCP proxy between the VM and the phone to capture and analyze the proprietary traffic.

• 4

  Brute force worked surprisingly well — Claude iterated through all two-letter command combinations, found about 80 valid commands, and used the phone’s error pattern (ER plus echoed input) to map the protocol surface.

• 5

  The ‘encryption’ was basically a one-byte checksum — Once Claude isolated the TS command and its binary payload, it inferred and verified that the missing piece was a simple single-byte checksum, making the protocol practical to reproduce.

• 6

  The whole project was cheap and reusable — Boris estimates the Claude usage at roughly $10 to $100, then turned the result into an open-source skill so anyone with a Viking phone can program it without spinning up a Windows machine.