The Challenge of Legacy Hardware

ElevenLabs attempted to integrate a legacy Viking VoIP phone into a modern AI-powered installation but faced a significant barrier: the device relied on obsolete Windows XP software that was incompatible with modern macOS environments. Previous attempts by senior engineers and earlier LLMs over the course of a year failed to establish communication with the hardware. The goal was to bypass the proprietary software and interface the phone directly with an AI agent.

Reverse Engineering via Claude Code

Boris Starkov utilized Claude Code to systematically decode the phone's undocumented communication protocol through a multi-stage process:

  • Network Discovery: Claude Code performed an nmap scan to identify the correct communication port (moving beyond an initial incorrect port).
  • Brute-Force Command Discovery: By sending random strings and observing error responses, the model identified that the device used two-letter command codes. It then brute-forced all 676 possible combinations, identifying 80 valid commands.
  • Traffic Interception: To solve the issue of non-persistent memory settings, Starkov set up a TCP proxy on his Mac. This allowed him to run the original Windows XP software in a virtual machine while simultaneously intercepting and logging the raw traffic between the software and the phone.
  • Checksum Analysis: The final hurdle was a one-byte checksum in the persistence command. Claude Code analyzed known input-output pairs, identified the pattern as a simple subtraction, and verified the formula through closed-loop iteration.

The Human-AI Collaboration Model

Starkov describes his role as the "hands" for the AI. While Claude Code provided the intellectual orchestration—analyzing logs, suggesting commands, and identifying the checksum logic—Starkov performed the physical tasks, such as rebooting the phone and reporting auditory feedback (beeps) to the model. This collaboration allowed a non-security engineer to successfully reverse-engineer proprietary hardware in approximately two days. The resulting protocol was open-sourced as a Claude Code skill, enabling others to configure the phone without the original Windows software.