An implementation of RFC 1149 "A Standard for the Transmission of IP Datagrams on Avian Carriers" for Minecraft.
Packets are physically carried between blocks by chickens. Their natural inability to fly, navigate obstacles, or survive mob attacks reproduces real IP-style packet loss and latency — obstacles, water, mobs and accidental player attacks all become legitimate sources of network failure.
This Forge mod is, primarily, a joke. It is secondarily a hands-on sandbox for thinking about how lossy networks, forward error correction, and retransmission protocols actually behave when they run on top of physics instead of fiber.
What it adds
| Concept | RFC 1149 term | CluckNet realisation |
|---|---|---|
| Sender host | Origin gateway | Packet Sender block (red top) |
| Receiver host | Destination gateway | Packet Receiver block (blue top) |
| Datagram | IP datagram | CompoundTag payload on a chicken |
| Avian carrier | Carrier | Packet Chicken entity |
| MTU | 1500 bytes | 16 bytes (small on purpose so chunking is visible) |
| ACK / NACK | TCP ACK | A return chicken with packed missing-chunk indices |
| Forward error correction | (none in RFC 1149) | One XOR parity chunk per message |
How to use it (60-second version)
- Place a Packet Sender and a Packet Receiver somewhere a chicken can walk between (1-block step max, no water across the path).
- Sneak-right-click the Receiver, then sneak-right-click the Sender — they are now linked.
- Write a message in a Book and Quill (do not sign it) and drop it into the Sender's GUI.
- Watch chickens walk across the world carrying chunks of your packet.
- The Receiver hands you back a Written Book when reassembly succeeds.
- If a chicken dies, you get a paper item with the lost chunk's preview. If too many die, a NACK chicken is automatically sent back and the Sender retransmits the missing chunks.
/clucknet stats prints process-wide packet counters (data / parity / retransmit / NACK / chickens lost).
Why chickens specifically?
- Chickens cannot fly. They glide, get stuck on 1.5-block ledges, drown in water, and die to wolves.
- A 13-block walk between sender and receiver is the throughput bottleneck and a constant source of dropped packets — exactly what you want from a best-effort delivery substrate.
Delivery semantics
The receiver follows TCP-like delivery: a message is delivered as soon as enough chunks have arrived to reconstruct it. It does not wait for every expected chicken.
- All N data chunks arrive → reconstruct & deliver. Late parity chunk silently dropped as redundant.
- N − 1 data chunks + parity arrive → XOR-recover the missing chunk & deliver. Any later-arriving data chunk for the same message is dropped.
- Fewer than enough within 60 s → broadcast
incomplete; the message ID is remembered for another 60 s so very-late chunks are not mistaken for a new message.
The trade-off: visually, the chat message often appears before all the chickens have walked in. The late chickens then arrive, are recognised as redundant, and are silently dropped. This is the network operating at maximum throughput.
Requirements
- Minecraft 1.20.6
- Minecraft Forge 50.1.x
- Java 21 (Gradle downloads it on first run if missing)
CluckNet currently targets 1.20.6 / Forge only. Ports to 1.20.1 (Forge) or 1.21.x (NeoForge) as PRs are welcome — see the GitHub repository for details.
More
- Full README, protocol details, troubleshooting: https://github.com/hijimasa/CluckNet
- Source / issues: https://github.com/hijimasa/CluckNet/issues
- Background: RFC 1149 (1990-04-01) and RFC 2549 (1999-04-01).
License
MIT. See LICENSE.
External resources
Project members
hijimasa
Member