FIBRE module (`blvm-fibre`)

UDP/FEC block relay as a loadable Commons module. Distinct from Dandelion++ transaction relay in Privacy relay.

Overview

blvm-fibre implements FIBRE-style block transport:

Outbound: on NewBlock / BlockMined, fetches the block via NodeAPI::get_block, FEC-encodes, and sends UDP chunks to registered FIBRE peers.
Inbound: assembles chunks and enqueues raw block bytes via NodeAPI::queue_received_block_bytes (same validation path as P2P BlockReceived).

The node core advertises NODE_FIBRE on P2P and emits companion-UDP events when peers advertise FIBRE (UDP port = peer TCP port + 1) for dynamic peer registration.

Wire types and FibreConfig live in blvm-protocol (fibre feature). The module crate owns UDP, Reed–Solomon, and relay logic.

Repository: BTCDecoded/blvm-fibre

Requirements

blvm-node with modules enabled.
Module listed in registry/modules.json (bootstrap via [modules] version pin) or built locally.
Do not bind the same UDP port twice on one host (only one FIBRE listener per deployment unless ports are explicitly separated).

Loading

Pin in blvm.toml (example):

[modules]
registry_url = "https://raw.githubusercontent.com/BTCDecoded/blvm/main/registry/modules.json"
blvm-fibre = "0.1.*"

Or place a release binary + module.toml on the module search path. See Module catalog — Installing modules.

Configuration

Module config.toml (or [modules.blvm-fibre] overrides):

Key	Purpose
`fibre.enabled`	Enable relay when `true` (nested `fibre` table / `FibreConfig`)
`udp_bind`	UDP listen `host:port` when not using TCP+1 follow mode (default `0.0.0.0:8334`)
`udp_follow_node_tcp_plus_one`	Listen on node P2P TCP port + 1 (node injects `MODULE_CONFIG_NODE_P2P_LISTEN_*` on spawn)
`register_peers_from_p2p`	Register peers that advertise `NODE_FIBRE` on P2P (UDP = peer TCP port + 1)
`[[fibre_peers]]`	Static outbound targets: `peer_id`, `udp_addr`

FEC and timeout options are under the nested fibre table (FibreConfig in protocol), including fibre.enabled.

Example — follow node P2P port (mainnet P2P 8333 → FIBRE UDP 8334):

udp_follow_node_tcp_plus_one = true
register_peers_from_p2p = true

Example — static peer:

[[fibre_peers]]
peer_id = "relay-east"
udp_addr = "203.0.113.10:8334"

Events

Event	Module action
`NewBlock`	`get_block` → encode → send to registered FIBRE peers
`BlockMined`	Same outbound path for locally mined blocks
`CompanionUdpPeerRegistered`	Optional dynamic peer registration from P2P
`CompanionUdpPeerUnregistered`	Remove dynamic peer

Capabilities (`module.toml`)

read_blockchain
subscribe_events
queue_inbound_block

Node vs module

	Node core (`blvm-node`)	`blvm-fibre` module
FIBRE UDP/FEC	Not implemented in-process	Subprocess + IPC
P2P	Advertises `NODE_FIBRE`; companion UDP events	Registers peers; sends/receives UDP
Config	Module pins / `[modules.blvm-fibre]`	Module `config.toml`
Operator docs	Privacy relay	This page

Troubleshooting

Symptom	Check
No outbound FIBRE sends	Peers registered? `NewBlock` firing? `get_block` returns block?
UDP bind fails	Port clash with P2P+1 or another FIBRE listener; firewall
Blocks not accepted from FIBRE	`queue_received_block_bytes` path; check module logs
Dynamic peers missing	`register_peers_from_p2p = true`; remote advertises `NODE_FIBRE`

BLVM Documentation