OptionalContentOptional wire content-type for the websocket leg (defaults to audio/l16;rate=8000).
OptionalEventOptional event-webhook URL passed on outbound createCall.
The WebSocket media pump (bidirectional audio).
The wss://… media endpoint the call's connect NCCO opens.
The Voice-API client surface (outbound dial / hangup / transfer / DTMF).
Options RealVonageBindings needs at construction — the injected client surfaces + the media URL.