Published reference

Open protocol · Codec 2 · callsign routing · reflectors

M17

M17 is part of the experimentation and interoperability layer. Treat current clients, reflectors and network behavior as moving parts and verify them against primary project sources.

Experimental does not mean undocumented.

What it is

M17 is an open-source digital voice/data protocol developed by and for amateur radio operators. Its voice path uses the open Codec 2 codec, and the project publishes specifications and software openly.

Where it fits at K6RCS

M17 is a natural K6RCS learning and experimentation layer: QSO One, gateways and hotspot software can make it accessible without turning the station into a museum of mode-specific radios.

Identity and addressing

CallsignHuman-readable amateur identity rather than a vendor-issued numeric identity as the primary concept.
ReflectorInternet routing/conference target.
ModuleSubdivision on a reflector where used.
Gateway/modemSoftware/hardware layer between RF and the network.

Setup order

  1. Start with the current M17 specification/docs, because the project is actively evolving.
  2. Choose the client/gateway path and prove local audio/modem operation.
  3. Connect to one reflector/module and verify callsign presentation and audio.
  4. Document the known-good software version and configuration before experimenting with bridges.
Test sequence: prove receive first, then local RF/audio, then the network connector, then the destination, and only then cross-mode or bridging. Change one layer at a time. The goal is to learn which thing works, not merely achieve a temporary miracle.

Common failure modes

  • Using an old blog post as if it were the current specification.
  • Bridging multiple systems before one native path is known-good.
  • Forgetting that “open” does not mean “unchanging.”

Security and privacy

Do not publish passwords, API keys, device UIDs, hotspot security values, local IP addresses, management URLs, or detailed behavioral schedules. Keep backups of known-good codeplugs/configurations, use unique credentials, and document firmware/software versions before changing them.

Primary sources and directories