Uncovering a Hidden WebRTC Bug That Breaks iOS Data Transfer Through Tailscale

This debugging story reveals a critical issue in WebRTC data channel communication on iOS when using Tailscale, where data mysteriously fails to arrive despite successful handshakes. The discovery of a hardcoded constant in webrtc-rs combined with a single-line design choice in Tailscale highlights how subtle interactions between libraries and network infrastructure can cause elusive bugs that resist traditional troubleshooting. For developers building peer-to-peer applications across platforms, this case demonstrates the importance of comprehensive logging and the hidden complexity lurking in cross-platform network protocols.