Signaling Protocol

Signaling carries SDP / ICE exchange and a set of control messages over WebSocket. The shared protocol models live in signal-facade/, and the signaling server itself is in signal/.

Message Types

Signaling messages are modeled as the SignalingType enum in signal-facade/src/model/signal.rs. Each variant has a unique integer value and is handled exhaustively in handle_message in signal/src/service.rs — there is intentionally no _ => catch-all, so the compiler enforces that every type is handled.

Authentication

Signaling endpoints authenticate differently depending on who connects — see Signaling Authentication. In short:

• Desk Server → Signaling uses a token in the WebSocket URL query string.
• Browser → Signaling uses the Actix-Session cookie, with no token parameter.

Adding a New Signaling Type

1. Add a variant (with a unique integer value) to SignalingType.
2. Handle it in handle_message — add a forwarding branch or a dedicated match arm.
3. Update the frontend: regenerate the client and add an onMessage handler in the frontend RTC hook.

See the Module Map for the cross-cutting checklist.