Primary WAN cuts during the Tokyo ISP window and the Edge pair flips straight to local survivability on 2024.6.1. The R750 phones register fine after the SIP 403 clears up, but the WebRTC softphone clients just hang on the media path. Architect flow is using the WebRTC Connect node with the 2024.5.2 SDK. WebSocket upgrade returns 1006 Abnormal Closure the moment the edge-rtc service switches to the local media gateway.
Console shows ICE_CANDIDATE_REJECTION: candidate_type not supported in survivability mode. BIOS network stack check shows the VLAN tagging remains correct on the management port. The public STUN server is reachable from the edge, but the local TURN allocation times out. We’ve tried adjusting the rtc.localMediaRouting.enabled flag in the config JSON, but the dial tone never arrives.
Predictive outbound campaigns are doing jack all while this stalls. The softphone UI spins for 45 seconds before throwing a generic network error. Edge telemetry shows the CPU idle at 12 percent, so it’s not a resource bottleneck. The media routing table simply refuses to update when the primary link drops. NIC link speed stays at 1Gbps full duplex, so physical layer is stable. Mic stays hot. Audio just echoes back.
Log snippet from edge-rtc.log:
2024-11-14T02:18:43.112Z [WARN] rtc.handshake failed: WS_1006
2024-11-14T02:18:43.115Z [ERROR] ice.candidate.reject: type=host, reason=survivability_mode_active
2024-11-14T02:18:43.118Z [INFO] rtc.media.path: fallback to local gateway timed out