UDP

The UDP plugin binds to any UDP endpoint and streams every received datagram into the workbench as a JSON envelope. Useful for debugging any UDP-based protocol without a dedicated plugin: DIS (when you want raw bytes alongside Bowire.Protocol.Dis's typed decoding), NetFlow, syslog, game-server telemetry, custom sensor feeds, …

Package: Kuestenlogik.Bowire.Protocol.Udp (sibling repo, not bundled with the CLI)

Setup

bowire plugin install Kuestenlogik.Bowire.Protocol.Udp

Standalone

bowire --url udp://239.255.0.1:3000

Embedded

app.MapBowire(options =>
{
    options.ServerUrls.Add("udp://239.255.0.1:3000");
});

URL shapes

udp://127.0.0.1:5514          # unicast — listen on loopback port 5514
udp://239.255.0.1:3000        # multicast — joins the group
udp://255.255.255.255:3000    # limited broadcast
udp://192.168.1.255:3000      # subnet-directed broadcast
udp://broadcast:3000          # shortcut for 255.255.255.255
udp://multicast:3000          # shortcut for 239.1.2.3

The transport mode is inferred from the IP address — multicast (224.0.0.0/4) joins the group, broadcast (255.255.255.255 or any address ending in .255) enables SO_BROADCAST, everything else binds as unicast.

Envelope

Each datagram arrives as:

{
  "source": "10.0.0.5:53812",
  "bytes": 144,
  "text": "optional UTF-8 decoded string when the payload is valid UTF-8",
  "raw": "<base64 of the full datagram>"
}

text is absent (JSON null) when the payload contains non-UTF-8 bytes; the raw base64 is always present so the workbench can hex-dump it regardless.

Mock replay

UdpMockEmitter plugs into the bowire mock server. Any recording with steps tagged protocol: "udp" gets re-broadcast on UDP at the original cadence (from capturedAt), honouring MockEmitterOptions.Loop / .ReplaySpeed.

Destination is read from the first UDP step's metadata, with sensible defaults:

Metadata key	Purpose	Default
`destination`	Full `udp://host:port` URL (overrides `host`/`port`)	`udp://255.255.255.255:3000`
`host` / `port`	Alternative, set individually	`255.255.255.255` / `3000`
`ttl`	Multicast TTL; ignored for broadcast / unicast	`1`

Transport mode (multicast join / SO_BROADCAST / plain unicast) is inferred from the destination IP, the same classifier the discovery side uses — a multicast recording replays as multicast, a broadcast recording as broadcast, and so on.

Payload source: responseBinary (base64 raw bytes) is preferred; otherwise the emitter falls back to body encoded as UTF-8, so text-only recordings (syslog, human-readable telemetry, …) still replay.

Relationship to the DIS plugin

Bowire.Protocol.Dis gives you typed DIS replay (entity discovery, PDU filtering, typed envelopes per IEEE 1278.1). UDP is the low-level cousin — it doesn't decode any protocol, it just surfaces bytes. Run both at once: DIS on one URL for typed per-entity streams, UDP on the same port for the raw-bytes view. Pick the protocol string (dis vs udp) on your recording steps to route them to the right emitter.

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