Call and screen-share diagnostics

Call debugging works best when you separate signaling, ICE, media, and browser-capture problems.

1. Confirm RTC config#

Use Plainwire's connection diagnostics and check that STUN/TURN status is ready. Provider tokens should never appear in browser output.

2. Test two networks#

Use, for example, home broadband and a phone hotspot. Two clients on the same LAN do not prove TURN works.

3. Force TURN temporarily#

PLAINWIRE_ICE_TRANSPORT_POLICY=relay

Restart and test. Inspect browser WebRTC internals to confirm a relay candidate pair. Restore all when finished.

4. Separate microphone and screen problems#

Screen capture depends on browser and OS permissions. Shared system/tab audio availability varies by platform. A successful voice call does not prove screen-audio capture is available.

5. Watch reconnect behavior#

Test:

brief Wi-Fi loss;
network change;
page refresh;
mute/deafen transitions;
TURN credential refresh during a long call;
start/stop/change screen source.

6. Use call-health data carefully#

Plainwire's optional native call-health worker reports numerical heuristics. It is not a MOS guarantee or a substitute for browser/WebRTC metrics.

Common causes#

TURN URLs unreachable by firewall;
bad coturn external-ip behind NAT;
TLS certificate mismatch on turns:;
relay port range blocked;
provider credential expired;
browser permission denied;
corporate network blocks UDP, requiring TCP/TLS relay.