I published a new architecture recap on building WebRTC calls around a Go gRPC signaling layer and Android clients in constrained LAN environments.
The design is intentionally split into clear ownership boundaries:
- gRPC signaling handles device state, session control, and event delivery.
- WebRTC owns SDP/ICE negotiation, media tracks, selected candidate pairs, and transport state.
- Android clients own runtime permissions, audio/video resource management, UI state, and lifecycle cleanup.
- An RTC Gateway gives the system a place for discovery, recovery, session mapping, and observability.
The main lesson is that call setup is only the beginning. The real engineering work is in recovery and observability: LAN paths can change, devices can restart, sessions can become stale, audio quality can degrade, and gateway state can drift away from client state.
Full write-up:
https://www.lodan.me/posts/webrtc-grpc-lan-call-architecture/
This is part of a longer series on WebRTC reliability, AEC dump debugging, server-side noise suppression, and RTC Gateway concurrency issues.
