BeanheimNet

Networking fixes for Valheim 1.0 dedicated servers and clients, with built-in telemetry. One DLL, installed on the server and on every client. No version lock: a player without it still connects and plays vanilla.

The problem

Valheim keeps at most 10 KB of object updates in flight per player and pins Steam's send rate at 150 KB/s. A player 150 ms away can receive at most about 68 KB/s, and the same limit caps what each player uploads. Building pieces are always sent before creatures, carts and dropped items. Fish and ambient animals write an update every frame they move. On a busy server this shows up as creatures that stutter or teleport, carts that freeze and snap, drops that appear seconds late and hits that land late.

What it does

Everything players cannot see ships on. The two features that change what players see, Cleanup and ItemMerge, ship off.

Before and after

Version 0.3.0, two players, one on LAN and one at 48 ms ping, at a large base on a heavily modded server. Features were switched off for ten minutes and back on for ten, live, with telemetry running throughout. The server and the LAN player's client were switched; the other client stayed on 0.2.2 the whole time.

Deferred counts an update once for every send round it waits.

Not everything is better. With features on the server used 8 points more of one core. The remote player's app ping, a round trip through the game's own send queue (Steam's ping was 47 ms), was 131 ms while entering an area with features on and 106 ms with them off, because a larger window queues more; at rest it was 106 ms and 108 ms. The LAN player's fell from 33 ms to 16 ms, one server frame. The LAN client also counted more position corrections of 2 m or more with features on (805 against 644), in a window where it received far more updates of nearby moving objects.

Setup

• Install on the server and on every client (BepInEx 5).
• Config: BepInEx/config/helix.beanheim.net.cfg. Edits are picked up within 5 s. No restart.
• On/off switches are in the numbered sections. Tuning values are in [99 Advanced], named Section.Key (for example Scheduler.SendIntervalSeconds). Upgrading from 0.2.1 or 0.2.2 moves them there once and keeps the values you had changed. A 0.2.0 cfg uses older section names and starts at the defaults.
• Some defaults differ by side: a dedicated server gets a 60 fps frame cap, Scheduler.SendIntervalSeconds 0.033 and RelayThrottle.OtherHz 0,5,3; clients keep 0.05 and 0,0,0. Values are written into the file, so a cfg copied from one side to the other carries that side's values.
• Dedicated servers do not read console input. Use the one-shot keys under [11 Triggers] (Census, ItemReport, ItemCleanupOnce, Stats): set one to true, it runs and resets itself.
• Clients: console command bnet stats | census | items | cleanup dryrun|run | reload | config.
• Rollback: [01 General] Enabled = false, live, makes every patch behave like vanilla. Delete the plugin folder to uninstall. Nothing persists in the world except Cleanup deletions and ItemMerge merges, and only if they were enabled. 0.2.2 does not read [99 Advanced]: to downgrade, put back the cfg you had before 0.3.0.

Advanced

Settings

The tuning values below are in [99 Advanced] under the section name shown.

• SendWindow: window = ping × TargetRateKBps (300) × BdpFactor (1.25), clamped between MinWindowBytes (32768) and MaxWindowBytes (65536); vanilla 10240 when there is no ping reading. Includes queue-drain compatibility for mods that wait on the socket queue (ServerSync, Jotunn, ConditionalConfigSync) and raises Jotunn's MaximumSendQueueSize while on. Refuses to install if ZDOMan.SendZDOs does not have the expected shape.
• Scheduler: SendIntervalSeconds (0.033 on a dedicated server, 0.05 on clients) caps send rounds per player per second; FrameBudgetMs (4) bounds the time spent per frame. ServerTargetFrameRate (60; 0 = vanilla 30) applies to a dedicated server only and follows the master switch, not the Scheduler switch. In the measurement above it was switched together with the other features, so the frame time and CPU there are for everything at once.
• SteamTransport: SendRateMin and SendRateMax set to SendRateKBps (1024). Steam requires them equal. Applied globally and to live connections, and read back. SendBufferBytes (0 = Steam's default) sets Steam's send buffer; the original size is put back when it returns to 0.
• RelayThrottle: rates in updates per second as near/far/beyond: fish 6/3/2, creature ∞/10/5, item ∞/5/3, floating ∞/5/3, effect 10/5/3, other ∞/5/3 on a dedicated server and ∞/∞/∞ on clients. Bands at NearMeters (40) and FarMeters (100). Distance is measured from the receiving player on the server and from the nearest loaded player on the client upload. Never throttled: never-sent objects, ownership changes, force-sends, players, ships, carts and non-Default object types. Nothing is dropped; a held update goes in the next round.
• Priority: score = distance − AgeWeight (1.5) × seconds since the last sync − SolidBiasMeters (64) for building pieces − NewNearBonusMeters (200) for never-sent objects inside NearMeters. Foreign-owned Prioritized objects and terrain keep their top tiers. Uses the live character position instead of the one the client reports every 2 s.
• Deadband: item 0.02 m / 2°, creature 0.01 m / 1°, other 0.01 m / 1°, velocity 0.05 m/s. Measured against the last written value, not the last frame. When an object comes to rest its velocity, and its body velocity, is written as exactly zero once, so other players' games stop moving it. Never players, carts or Prioritized objects. A ship with nobody aboard gets its own band, 0.05 m / 2°, while it is still; vanilla ships are Prioritized, so this reaches only modded ships of the default object type.
• Items: Cleanup deletes items older than MaxAgeHours (6) of played time, farther than ProtectRadiusMeters (200) from every player, not within BaseProxyRadiusMeters of a BaseProxyPrefabs piece, in water when OnlyInWater is set, and not matching ProtectedPatterns. An item with custom data (every EpicLoot enchantment), a quality above 1, a max stack of 1 (all gear) or unreadable item data is never deleted. Every condition is checked again at the moment of deletion. Every deletion is logged.
• ItemMerge: same name, quality 1, variant 0, no custom data, within MergeRadiusMeters (5), checked every MergeIntervalSeconds (30). Vanilla auto-stacks at 4 m, once per item and only while more than 200 drops are loaded.

Reading the stats line

• deferred: updates that did not fit the window this round. Sustained non-zero with two or more players means the window is the limit. With one player it is always 0.
• refused: rounds that sent nothing because the queue was above the window.
• rtt is Steam's ping; app is a ping through the game's own send queue. app includes one server frame and one client frame (about 16 ms with the server at 60 fps, 33–76 ms at 30), so the queueing delay is app − rtt − floor.
• throttled: updates held back by RelayThrottle this interval. They are sent later, not dropped.
• frame avg on a server line is the server's frame time; frames >50ms N >100ms N counts long frames in the interval. sched frames/served/budget-breaks appear when Scheduler is on.
• gc N heap N MB cpu N%: garbage collections of any generation in the interval, managed heap size, and process-wide CPU as a share of one core. A long frame with low cpu is waiting, not working.
• steam-status ok N not-ok N last <EResult> appears when Steam's connection-status call fails; that player's window stays vanilla until it works.
• Vanilla's own Connections N ZDOS:X sent:Y recv:Z line is the cross-check. Both counters are 0 with one player.
• To measure a change: turn one toggle off in the cfg, play ten minutes, compare the lines, turn it back on.

Telemetry

These lines only read; nothing is sent or changed. Each has a toggle in [08 Telemetry], on by default.

• peerx <player> (server, after each peer line; PeerExtras): qtime is Steam's queue time and loss the local and remote packet loss. relay delay near is how long a moving object near that player waited before it was relayed (95th percentile and max); pending>250 counts each time an object near them went more than 250 ms without being relayed. owners near self/other/none is who owns the creatures within 40 m of them. owner changes N p2p N counts creature ownership changes involving them, and how many moved straight between two players. helm!=owner reads the whole interval when, at the check, this player holds the helm of a ship somebody else owns, and 0 otherwise (-1 if that part could not be installed). silence max is the longest gap between pings from that player.
• client (client, after the stats line; ClientExtras): gaps near is the time between updates of moving objects near you, bucketed <100/<250/<500/<1000/≥1000 ms. jump is how far an update moved an object from where your game expected it (≥0.5 m, ≥2 m), and snaps an object moving 4.9 m or more in one step, split by creature, player and ship; other objects count in the totals only. A move of 100 m or more is a teleport and is not counted. nettime corr is the clock corrections from the server, inst pending and created/s the objects waiting to be created, zdodata the object data received.
• desync (server; DesyncCounters): ghost-miss counts copies left out of date after an object crossed a zone border. misrouted counts damage aimed at a creature, fish or player that reached nobody able to apply it: another player who does not own the target (peer), the server (server) or nobody (none). rpc top lists routed RPCs by name with their recipient counts.
• census ghosts and census types (server, at boot and on the Census trigger): planned (*_planned) pieces by zone and age, and every object counted by class and network type.

Diagnostics

All off by default, in [12 Diagnostics], and live.

• Profiler (both sides): a prof line per interval with the time per frame by phase, the busiest update methods, BeanheimNet's own hooks and its own overhead (self). Its hooks are installed a few per frame when it turns on and removed when it turns off.
• ReflectionSampler (both sides): a refl line counting reflection calls on the main thread and naming the code that makes them in long frames. It captures a call stack for a small sample of calls, so leave it off unless you are chasing long frames.
• GcTimeSliceMs (dedicated server): Unity's incremental garbage-collector time slice in milliseconds, for measuring long frames. 0 leaves Unity's value alone.

Compatibility

Every private game member is bound once at startup. A missing member disables only the features that need it, with a logged reason. Every patch body is wrapped: an exception logs once per minute and that call falls back to vanilla. If Smoothbrain Network, ValheimTune, NetworkPerformanceSystem, ReturnToSender, BetterNetworking, BetterNetworking_Valheim, VBNetTweaks, FiresGhettoNetworking, SkadiNet, WarheimNetwork or NetworkTweaks is loaded, only telemetry is installed; the frame-rate setting, ItemMerge and item cleanup stand down too. At boot the plugin lists every other Harmony patch owner of the methods it touches ([owners] lines).

Credits

Some ideas come from Network Performance System, FiresGhettoNetworking, LeanNet and Smoothbrain Network. Ideas only; no code was copied.

Changelog

0.3.1 — 2026-09-27

• Every on/off switch is now in [01 General] under its own name, listed in a fixed order in ConfigurationManager: Enabled, then SendWindow, SteamTransport, Scheduler, RelayThrottle, Priority, Deadband, Telemetry, StatsFile, PeerExtras, ClientExtras, DesyncCounters, CensusOnBoot, ItemReport (was [09 Items] ReportEnabled), ItemCleanup (was Cleanup), ItemMerge, and the one-shot RunCensus, RunItemReport, RunItemCleanupOnce, RunStats (were [11 Triggers]). Tuning values stay in [99 Advanced] and diagnostics in [12 Diagnostics]. The first start moves the switches once, keeps anything you had changed, and logs config: moved N switches to [01 General]: ....
• BeanheimNet no longer switches itself to telemetry only when another networking mod is loaded. It logs a warning naming that mod and keeps running. The two are not compatible; remove one of them. The stats file's boot line says conflicts= instead of refused=.
• README rewritten: what you might want to change, installing with a mod manager, and a plain compatibility note. The package description no longer says "No version lock"; a player without the mod can still join, as before.

0.3.0 — 2026-09-27

Settings

• The on/off switches stay in the numbered sections. The 51 tuning values moved into one [99 Advanced] section, each named after its old section (Scheduler.SendIntervalSeconds, RelayThrottle.OtherHz, ...).
• The first 0.3.0 start carries values over once from a 0.2.1 or 0.2.2 cfg (a 0.2.0 cfg uses older section names and starts at the defaults) and logs config: moved 51 settings to [99 Advanced]: kept N changed values .... A value you changed is kept. A value equal to the old default counts as a default, so the new default applies. If a [99 Advanced] key is already in the file, it wins, and a differing old value is named in a warning.
• New defaults on a dedicated server: Scheduler.ServerTargetFrameRate 60, Scheduler.SendIntervalSeconds 0.033, RelayThrottle.OtherHz 0,5,3. Clients keep 0.05 and 0,0,0; the frame-rate setting does nothing on a client.
• A cfg copied from a server to a client (or back) carries the other side's values, because they are written into the file.
• Downgrading to 0.2.2 ignores [99 Advanced] and runs 0.2.2's defaults. Keep a copy of the pre-0.3.0 cfg if you may roll back.

Fixes

• Items: cleanup re-checks every condition for each candidate at the moment of deletion. The game recycles object records, so a record freed between the scan and the delete could belong to an unrelated object by then. Skips are logged as items: recheck skipped N at delete.
• Deadband: when a body comes to rest, its body velocity and angular velocity are written as exactly zero once, and the game's own write of the small leftover velocity is skipped that frame, so other players' games put the body to sleep. This matters for tree logs and some creatures; no item prefab syncs body velocity.
• Deadband: the moored-ship band applies only while the hull is still (horizontal speed at most 0.25 m/s, turning at most 0.1 rad/s). Vanilla ships are Prioritized objects, which the deadband never touches, so in 0.2.2 and 0.3.0 the moored-ship band only reaches modded ships of the default object type.
• When another networking mod is detected, the frame-rate setting, ItemMerge and item cleanup now also stand down; reports, census and stats continue.
• SteamTransport: reads Steam's send buffer size before changing it and restores it when SendBufferBytes goes back to 0 or the feature is switched off. SendBufferBytes is now applied at a SendRateKBps of 150 too. If the original size cannot be read, the buffer is left alone.
• A prefab that is not loaded yet is no longer classed as "other" for the rest of the session; it is looked up again after 30 s.
• Five more networking mods switch BeanheimNet to telemetry only: DIT.BetterNetworking10, com.Fire.FiresGhettoNetworkMod, sighsorry.SkadiNet, dzk.warheimnetwork, Searica.Valheim.NetworkTweaks.
• 0.2.1 said the mod no longer referred to any particular installation. That was incomplete: some comments and descriptions still did, and the DLL carried a local build path. Both are removed.

Telemetry (every new line reads only; nothing is sent or changed)

• peerx (server, after each peer line): Steam queue time and packet loss, how long a moving object near that player waited before it was relayed, who owns the creatures near them, ownership changes (and how many moved straight between two players), helm holder vs ship owner, the longest silence.
• client (client, after the stats line): arrival gaps of moving objects near you, position corrections (jumps and snaps) by creature/player/ship, clock corrections from the server, objects waiting to be created, received object data.
• desync (server): copies left out of date after an object crossed a zone border, damage sent to a player who does not own the target, routed RPCs by name.
• census (server): PlanBuild ghost counts by zone and age, and object counts by class and type.
• gc on the stats line counts every garbage collection in the interval; it was described as gen-0 only.

Diagnostics ([12 Diagnostics], all off by default, live)

• Profiler: a prof line with per-frame time by game phase, the slowest named systems, BeanheimNet's own hooks and its own overhead.
• ReflectionSampler: a refl line naming which code makes reflection calls in long frames.
• GcTimeSliceMs (dedicated server): sets Unity's incremental garbage-collector time slice, for measuring long frames. 0 leaves Unity's value alone.

0.2.2 — 2026-09-22

• RelayThrottle: two new object classes. FloatingHz (default ∞/5/3) for floating objects that are neither items nor creatures (prefabs with a Floating component: logs, debris), which were unthrottled at any distance and the top uplink talker at a harbour; EffectHz (default 10/5/3) for networked sfx_/vfx_ prefabs (a sound that follows a bird). Floating objects use the item deadband.
• Deadband: a ship with nobody aboard gets its own deadband (MooredShipPosMeters 0.05, MooredShipRotDegrees 2); a ship with a player aboard, players and carts stay untouched. Ship.HasPlayerOnboard is bound once at startup; if it is missing only this part is skipped.
• Items: an item whose item data cannot be read (no data blob) is treated as valuable and never deleted, like enchanted, quality and gear items.
• Telemetry: the stats line gains frames >50ms N >100ms N and gc N heap N MB cpu N% (gen-0 collections in the interval, managed heap, process-wide CPU as a share of one core).
• Text: the Commands boot line names the 11 Triggers section; three leftover feature-key labels removed from a log line and two cfg descriptions.
• README rewritten: short overview, before/after numbers from a live two-player A/B, settings and stats-line details under Advanced, build notes removed; manifest description shortened.

0.2.1 — 2026-09-21

• cfg sections renamed to plain names (02 SendWindow, 03 Scheduler, 04 SteamTransport, 05 RelayThrottle, 06 Priority, 07 Deadband, 08 Telemetry, 09 Items, 10 ItemMerge, 11 Triggers); log tags match. Existing cfg files keep the old sections as orphans and the new ones start at defaults.
• Scheduler credit carries across slow frames (a peer is still served at most once per frame), so a CPU-bound server reaches the configured rate.
• README, comments and cfg text no longer refer to any particular installation.
• MinWindowBytes defaults to 32768.

0.2.0 — 2026-09-21

• Defaults: everything invisible to players is ON (window, scheduler, Steam rate, throttle, priority, deadbands, telemetry); Cleanup and ItemMerge stay OFF. A vanilla baseline was measured first.
• Client uplink throttle measures distance from the nearest loaded player, not just the owner; gentler rates (fish 6/3/2, creature ∞/10/5, item ∞/5/3).
• MinWindowBytes defaults to 16384.
• Unwrap ServerSync's BufferingSocket wrapper to reach the real Steam socket (server-side status, window sizing and per-connection rate apply were inert without it).
• Client-side item merge; hard rule that enchanted / quality / gear items are never deleted.
• ServerTargetFrameRate; cfg Triggers; Steam status and per-connection diagnostics on the stats lines.
• Thunderstore packaging (tools/package.sh).

0.1.0 — 2026-09-20

First build, against Valheim l-1.0.15 (network version 40), BepInEx 5.4.23.5, Harmony 2.9.