When a P2P direct call establishes successfully but the underlying
network path dies (phone switched from WiFi to LTE mid-call, or
cross-relay media forwarding isn't working), the call stays up
silently with recv_fr frozen at 0. No feedback to the user.
New watchdog in the Android recv task: tracks consecutive
heartbeat ticks (2s each) where recv_fr hasn't advanced. After 3
ticks (6s) with no new packets, emits:
- call-event { kind: "media-degraded" } — user-facing warning
banner: "No audio — connection may be lost. Try hanging up and
reconnecting, or switch to a different relay."
- call-debug media:no_recv_timeout for the debug log
If packets resume (recv_fr advances), clears the banner via:
- call-event { kind: "media-recovered" }
JS listener creates/removes a red-tinted banner dynamically at
the top of the call screen. Banner is also cleaned up on
showConnectScreen (call end).
This covers:
- Direct P2P that established on WiFi but died when the phone
switched to LTE (stale NAT mapping, unreachable peer)
- Cross-relay calls where federation media isn't forwarding
(relay not upgraded, not federated, etc.)
- Any other "connected but silent" scenario
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>