Native NXDN AMBE+2 group voice over the NXDNReflector/MMDVM IP protocol. Voice bytes are relayed unchanged. No P25, Advanced, Opus, transcoding, synthesized speech or voice enhancement is present.
Use the configured UDP endpoint (default 41400), your callsign, a valid 16-bit NXDN radio ID, and an enabled talkgroup. Polls refresh the endpoint every second. Configure the server address and NXDN ID in MM-Digital or use an NXDN gateway.
Each talkgroup admits one transmitter at a time. Different groups operate independently. Late joiners receive the active call header before subsequent voice packets. Lost terminators expire after one second; continuous transmission is limited to three minutes by default. Rejected packets, contention, timeouts and send failures are counted.
IP, callsign and radio-ID allowlists, group policy and bounded capacity are set in config.toml. Empty allowlists permit public reflector access. The legacy UDP wire protocol does not authenticate identity cryptographically; private infrastructure should restrict IPs and run inside a VPN. The public dashboard is read-only. Administrative stop-call operations require a bearer token and are bound to loopback.
This is an IP voice core, not a Kenwood-certified NEXEDGE system controller. RF channel assignment, site controllers, roaming, manufacturer trunking backhaul, individual calls, encryption and 4400-bit/s full-rate vocoding are not implemented. Radio/gateway interoperability must be qualified on actual equipment.
Recent calls and counters survive a clean restart. Atomic, synchronized state snapshots occur every five seconds; an abrupt power loss may lose that interval. Journald records lifecycle events. Health reports missing telemetry, resource pressure, persistence and network errors. Metrics are available at /status/metrics.