UDP Forwarder

A lightweight UDP packet forwarder written in Rust. Listens on multiple ports and forwards all received packets to multiple destinations — useful for splitting game telemetry or any UDP stream to multiple consumers. Built as an optional companion to RaceIQ so sim racers can receive telemetry on all their gear and software simultaneously with minimum latency.

GUI Mode

Launch the app to configure everything visually — set the listen port, add or remove forwarding targets, and start/stop forwarding. Settings are saved automatically to config.ini.

udp-forwarder

On Windows, use udp-forwarder.exe or double-click the executable.

CLI Mode (Headless)

For servers or automation, run without the GUI:

udp-forwarder --headless              # uses config.ini next to the binary
udp-forwarder path/to/config.ini      # custom config path
udp-forwarder --version               # print version

Config Format

Create a config.ini:

[general]
listen_port = 5300

[forward.1]
ip = 127.0.0.1
port = 5301

[forward.2]
ip = 192.168.1.100
port = 5300

• [general] — listen_port is the UDP port to receive packets on
• [forward.*] — any section starting with forward defines a target. Each needs ip and port

Manual Install

If you prefer not to use the install script, grab a zip from Releases:

Platform	File
Windows (x86_64)	udp-forwarder-v*-x86_64-pc-windows-msvc.zip
Linux (x86_64)	udp-forwarder-v*-x86_64-unknown-linux-gnu.zip
macOS (Apple Silicon)	udp-forwarder-v*-aarch64-apple-darwin.zip

Each zip contains the binary and an example config.ini for headless mode.

Performance

Architecture uses parallel fan-out with one dedicated sender thread per target, pre-allocated broadcast ring buffer, connected UDP sockets, and 4MB socket buffers. Zero heap allocations on the hot path.

Run the benchmark: cargo bench

The benchmark is a black-box smoke test that spawns the actual binary in headless mode, sends real packets, and measures delivery and latency on external receivers.

Per-game latency (5 targets at 100 pkt/s, tested on M5 MacBook Pro):

	Forza Motorsport	ACC	F1 24	LMU / rFactor 2	iRacing	Max UDP
Packet size	331 bytes	608 bytes	1460 bytes	1684 bytes	2048 bytes	8192 bytes
Avg	68µs	67µs	53µs	63µs	67µs	71µs
P50	64µs	64µs	51µs	60µs	63µs	70µs
P95	109µs	106µs	84µs	100µs	107µs	111µs
P99	128µs	129µs	99µs	120µs	124µs	135µs
Max	158µs	150µs	137µs	181µs	145µs	147µs
Delivery	100%	100%	100%	100%	100%	100%

Zero packet loss across all games. Sub-135µs P99 even at 8KB packets.

Building from Source

cargo build --release

Binary outputs to target/release/udp-forwarder.