BandwidthOptimizer

BandwidthOptimizer is a client-and-server network optimization mod built for heavily modded Minecraft servers. It reduces repeated packet traffic from chunk travel, login synchronization, custom payloads, machines, storage systems, and idle clients while restoring the original encoded packet stream before normal Minecraft handling.

Both the server and every connecting client must install a compatible build.

Highlights

• Recoverable cross-frame streaming Zstd compression.
• Synchronized literal and template mapping for repeated packet structures.
• Ordered small-packet batching with protected flush and protocol boundaries.
• Verified full, ref, and patch chunk transport.
• Persistent client chunk reuse across reconnects and repeated terrain visits.
• Incremental cache writes, bounded retention, corruption recovery, and background maintenance.
• Light and deep idle traffic reduction with state restoration when play resumes.
• Uploadable BO Stats reports with charts, player history, packet attribution, cache results, bypass details, and idle-gate savings.
• On-demand OP diagnostics, including exact packet-class tracing.
• Compatibility work for Create-heavy environments, Velocity, Voxy, AutoFish, Aeronautics, and other network-intensive modpacks.

How It Works

BO operates after Minecraft or the mod loader has encoded a complete packet. It may map, batch, compress, or reuse those encoded bytes. The receiver restores the original packet bytes before vanilla packet decoding continues.

Cross-frame compression uses sequence and epoch validation. Missing or invalid boundaries trigger bounded recovery and stream resynchronization. Chunk reuse is hash-verified, and unavailable or stale references fall back to complete packet data.

Idle traffic reduction has separate light and deep states. Presentation-only traffic can be reduced while a player is inactive, then current block, entity, HUD, and supported mod state is restored when the player returns.

Measured Results

Bandwidth savings vary by modpack, player activity, proxy topology, and packet mix. The following results come from BO HUD snapshots and transport source reports collected on real heavily modded servers. They are historical measured baselines, not guaranteed results.

The primary ratio describes traffic that entered BO's managed transport path. Whole-server totals also contain direct packets, compatibility bypasses, cache reuse, and already compressed or media-like payloads, so those values should not be treated as pure compressor efficiency.

Live HUD Baselines

Environment	Client optimized flow	Server raw to actual	Server optimized flow	Direct flow	Players	Source
Create Delight Remake server 1	23.21 MB -> 3.93 MB (16.9%)	305.35 GB -> 51.12 GB (16.7%)	40.28 GB (13.2%)	49.46 GB (16.2%)	1	HUD snapshot, v2.7.6.10
Create Delight Remake server 2	24.51 MB -> 4.15 MB (16.9%)	516.70 GB -> 83.24 GB (16.1%)	57.57 GB (11.1%)	57.01 GB (11.0%)	4	HUD snapshot, v2.7.6.10

Managed Transport Baselines

Environment	Managed transport	Without WATUT/YSM-like streams	Notes
Create-focused core server	38976.09 MiB -> 9455.03 MiB (24.3%)	34580.44 MiB -> 5236.56 MiB (15.1%)	Mixed traffic containing large poorly compressible sources
Create-focused mirror server	1046.16 MiB -> 253.89 MiB (24.3%)	902.82 MiB -> 113.55 MiB (12.6%)	Smaller mixed sample with visible WATUT-like traffic
Create-focused test server	1174.31 MiB -> 112.24 MiB (9.6%)	Same sample	No WATUT/YSM exception in this TopN sample
Create Delight	7865.72 MiB -> 1622.43 MiB (20.6%)	7774.54 MiB -> 1539.90 MiB (19.8%)	Public modpack source-report snapshot
Create Delight secondary snapshot	4567.66 MiB -> 603.15 MiB (13.2%)	Not separated	Earlier report snapshot

High-Impact Packet Families

Source	Environment	Raw observed	Actual transmitted	Actual/raw ratio
ClientboundLevelChunkWithLightPacket	Create-focused core server	9062.88 MiB	481.85 MiB	5.3%
ClientboundLevelChunkWithLightPacket	Create-focused test server	713.65 MiB	16.84 MiB	2.4%
ClientboundTabListPacket	Create-focused core server	6354.97 MiB	655.45 MiB	10.3%
lightmanscurrency:network	Create-focused core server	8206.80 MiB	593.69 MiB	7.2%
create:deployer block entity data	Create Delight	510.41 MiB	71.61 MiB	14.0%

Low-Benefit Control Samples

Source	Environment	Raw observed	Actual transmitted	Actual/raw ratio	Path
watut:main	Create-focused core server	4157.94 MiB	3974.80 MiB	95.6%	BATCH_DIRECT_FALLBACK
yes_steve_model:2_6_0	Create-focused core server	514.63 MiB	510.50 MiB	99.2%	BATCH_TRANSPORT_SHARE
watut:main	Create-focused mirror server	146.07 MiB	143.07 MiB	97.9%	BATCH_TRANSPORT_SHARE
watut:main	Create Delight	91.18 MiB	82.53 MiB	90.5%	BATCH_TRANSPORT_SHARE

These control samples show why mixed-server totals can look worse than the high-impact packet families: a second compression layer has little room to help data that is already compressed, encrypted, media-like, or near-random.

Current 5.10.30.99 measurements have reduced managed traffic to about 3-11% of its original size. This is a substantial improvement over the historical baseline, but it is not guaranteed for every server; the final ratio depends on packet composition and the amount of reusable traffic.

Some modpacks may contain mod conflicts that cause abnormal network packets. BO cannot guarantee meaningful reduction of this abnormal traffic, but server operators can run /bandwidthoptimizer stats to upload a BO Stats report and locate its source.

Reproducing the Measurement

1. Install the same BO version on the server and every client.
2. Run a fixed activity pattern and duration, such as login bursts, repeated chunk travel, a machine-heavy area, or normal online play.
3. Run /bandwidthoptimizer stats and retain the returned BO Stats link.
4. Compare managed transport separately from direct and bypass traffic. Do not count bandwidthoptimizer:transport carriers as new source traffic.
5. Record the modpack, loader, Minecraft version, player count, duration, and BO version with the result.

Tested Environments

Compatibility and measurement work has included Create Delight, Brass Concerto, Aeronautics, and Mechanomania. Mechanomania's available historical snapshot contained bypass and packet-rank evidence but no source raw/actual summary, so it is listed as a tested environment rather than used for a compression-ratio claim. These tests do not guarantee every mod combination or proxy topology.

Supported Versions

Loader	Minecraft	Status
Forge	1.19.2	Release
Forge	1.20.1	Release
Fabric / Quilt	1.20.1	Release; Fabric API required
Fabric / Quilt	1.21.1	Release; Fabric API required
NeoForge	1.21.1	Release
NeoForge	26.1.2	Release
NeoForge	26.2	Beta

Installation

1. Download the build matching the Minecraft version and loader.
2. Install it in the server mods folder.
3. Install the same BandwidthOptimizer version on every client.
4. Install Fabric API for Fabric or Quilt builds.
5. Restart the server and clients.

Commands

Command	Purpose
/bandwidthoptimizer hud	Toggles the local client statistics HUD.
/bandwidthoptimizer stats	Uploads a server report and returns a clickable BO Stats link. OP only.
/bandwidthoptimizer debug	Opens on-demand diagnostic tools. OP only.

BO Stats

Run /bandwidthoptimizer stats as an operator to upload the current report. The returned bostats.torqueflux.com page presents server totals, player and time-period traffic, transport and cache behavior, packet-source attribution, bypass details, and idle-gate savings.

For disconnects or compatibility issues, include the BO Stats link together with client, server, and proxy logs around the incident.

Configuration

The default configuration is suitable for most servers and modpacks. Advanced administrators can tune the generated client and common configuration files after collecting comparable BO Stats reports before and after each change.

Links

• CurseForge: https://www.curseforge.com/minecraft/mc-mods/bandwidthoptimizer
• Modrinth: https://modrinth.com/mod/bandwidthoptimizer
• GitHub: https://github.com/duckgun13476/BandwidthOptimizer
• Discord: https://discord.gg/qdMbM9Rq6B

License

GNU LGPL 2.1 or any later version (LGPL-2.1-or-later).