ELKA VBAN TestingTool

ELKA VBAN TestingTool is a Windows desktop application for finding configuration and network-path problems in VBAN and VoiceMeeter systems. It combines the VoiceMeeter Remote API with passive VBAN packet observation, Windows routing and firewall evidence, device discovery, and an optional encrypted two-PC comparison.

It is designed to answer practical questions such as:

• Is the exact stream name the same at both ends, including case and invisible spaces?
• Is VoiceMeeter expecting the correct sender IP and UDP destination port?
• Are VBAN packets actually entering or leaving this PC?
• Which Windows interface, local IP, gateway, and route will be used?
• Is an explicit Windows Firewall rule relevant to the stream?
• When the tool runs on both PCs, can the same normal VBAN packets be observed at the sender and receiver?

The monitor is passive: it does not record, decode, play, save, block, or reinject audio. It reads the VBAN header and network metadata needed for diagnosis. The coordinated two-PC test observes existing VoiceMeeter or Matrix traffic; it does not create a synthetic VBAN audio stream.

Requirements

• Windows 10 or Windows 11, x64
• Administrator access for packet capture and firewall-rule changes
• VoiceMeeter installed for VoiceMeeter configuration reading/editing
• Two reachable Windows PCs for paired end-to-end comparison

Generic VBAN traffic from other applications, including Matrix, can still appear in the packet and device views. Automatic configuration editing is VoiceMeeter-specific because it uses the VoiceMeeter Remote API.

Download and start

1. Download the current Windows x64 ZIP from the repository's Releases page.
2. Extract the complete ZIP to a folder. Do not run the executable from inside the ZIP.
3. Run ELKA.VBAN.TestingTool.App.exe.
4. Allow elevation when prompted. Packet observation and firewall actions require administrator rights.
5. Leave VoiceMeeter or Matrix running and carrying the VBAN streams you want to inspect.
6. Select SCAN STREAMS.

Windows may show a SmartScreen warning for an unsigned community build. Review the repository and release checksum before choosing to run it.

Main areas

VBAN Diagnosis

This is the normal starting page.

• Diagnosis compares configured VoiceMeeter rows with recently observed incoming traffic. It reports exact-name, case, whitespace, sender-IP, destination-port, enabled-state, and close-match problems. A suggested fix changes only the confirmed VoiceMeeter setting and rescans immediately.
• VBAN In shows external VBAN packets entering this PC.
• VBAN Out shows VBAN packets leaving this PC.
• VoiceMeeter In / Out shows the VoiceMeeter VBAN rows. Select a row to edit it or run a staged route diagnostic.
• All Traffic combines incoming and outgoing observations.

Spaces in stream names are rendered as visible dots in tables and in the stream editor. A dot is only a display marker for a space; it is not written into the stream name. Unusual characters are not warnings by themselves. A mismatch is reported only when the exact names at the compared ends differ.

Devices

Devices shows only devices supported by current packet evidence or a real VBAN service identity response. Depending on what the sender advertises, it can display the source IP, host name, physical device, manufacturer, application, device type, language, supported sample rates, user, comment, streams, and port evidence.

RESCAN DEVICES sends standard VBAN service discovery requests to relevant observed/configured peers and refreshes the evidence. A second ELKA app is not required for this scan. Some products do not answer VBAN identity requests, so missing identity details do not prove that their audio stream is absent.

Network & Firewall

This page checks installed VB-Audio applications and the UDP endpoints used by configured streams.

• ALLOW APP IN + OUT creates application-scoped inbound and outbound Windows Firewall allow rules.
• ALLOW PORT IN + OUT creates explicit inbound and outbound UDP rules for the selected configured port.
• ALLOW MANUAL PORT IN + OUT does the same for a manually entered UDP port.

LocalSubnet limits a rule to machines Windows considers part of the local network. It does not expose the port to the public internet. Existing explicit block rules are not removed or overridden. Firewall changes require administrator rights and a confirmation prompt.

Two-PC Test

Run ELKA VBAN TestingTool on both PCs to obtain stronger sender-to-receiver evidence.

1. On both PCs, open TWO-PC TEST and select OPEN PEER FIREWALL if needed. Peer discovery uses UDP 6998 on the local subnet.
2. Wait for the other PC to appear as DISCOVERED.
3. Select PAIR. Verify that the displayed code is identical on both machines.
4. Select CONFIRM CODE on both PCs. The pairing is remembered for that Windows machine identity.
5. Ensure the normal VoiceMeeter or Matrix stream is running.
6. Use TEST LINK, or select a VoiceMeeter row and use DIAGNOSE SELECTED.

Once paired, diagnostic metadata is exchanged only through the authenticated encrypted peer channel. The five-second coordinated stream test filters on direction, peer address, exact stream name, and destination UDP port. Both PCs independently count the same normal VBAN traffic and compare frame ranges.

Changing from an older ELKA VBAN Extra build to TestingTool changes the peer identity/protocol name. Pair the two TestingTool installations again.

Understanding the data

Field	Meaning
Direction	IN entered this PC; OUT left this PC. Local outgoing traffic is not duplicated as incoming.
Source	Sender IP and the sender's temporary UDP source port. A high changing source port can be normal.
Destination	Receiver IP and the VBAN UDP destination port that must match the receiving configuration.
Stream name	Exact VBAN header name. Case, spaces, and punctuation are significant when comparing endpoints.
Format	VBAN protocol/type and, when available, audio sample rate, channel count, and sample format.
Frame	VBAN frame counter reported by the sender. It wraps; gaps or disorder can be evidence of loss/reordering.
Packets	Number observed for that grouped route/name entry during the current capture lifetime. It is not an audio sample count.
Last seen	How recently matching traffic was observed. Stale entries are removed automatically.
UDP listener	Local Windows endpoint evidence. UDP does not provide a delivery acknowledgement.
Firewall	Relevant allow/block evidence from enabled Windows Firewall rules. It is not proof about another PC's firewall.

Diagnostic status meanings:

• PASS — the stage has positive supporting evidence.
• WARNING — useful evidence exists, but a condition deserves attention or cannot prove delivery.
• FAIL — a concrete local failure or a confirmed sender/receiver observation gap was found.
• INCONCLUSIVE — available evidence cannot prove success or failure. This is normal for one-sided UDP checks.
• RUNNING — the stage is still collecting evidence.

Independent sender and receiver sampling windows do not start on the exact same packet. Packet totals can therefore overlap imperfectly even when receipt is confirmed. The frame range and exact route/name/port match are the stronger correlation evidence.

Selected-stream route diagnostic

Select a row under VoiceMeeter In or VoiceMeeter Out, then choose DIAGNOSE SELECTED. The report checks, in order:

1. required VBAN configuration and enabled state;
2. IPv4 address or host-name resolution;
3. the actual local interface and source IP Windows selects;
4. direct/gateway route, interface index, and metric evidence;
5. ICMP ping;
6. a limited-TTL route trace;
7. matching existing VBAN packet activity;
8. relevant local Windows Firewall rules;
9. paired end-to-end observation, when a matching trusted peer is available.

ICMP ping or trace failure is not treated as proof that UDP/VBAN failed: routers and firewalls often block ICMP while allowing UDP. Likewise, seeing an outgoing UDP packet proves local emission, not remote application receipt. Use the paired test for end-to-end evidence.

Privacy and security

• No audio payload is decoded, played, or saved.
• Observed packet metadata is bounded and kept in memory.
• The app does not upload diagnostics to a cloud service.
• Pairing requires matching user-confirmed codes on both PCs.
• Trusted peer data is authenticated and encrypted using Windows cryptography.
• Firewall and VoiceMeeter changes require an explicit user action.

Build from source

Open ELKA.VBAN.TestingTool.slnx in Visual Studio 2022 with the .NET desktop development workload, or use:

dotnet restore .\ELKA.VBAN.TestingTool.slnx
dotnet build .\ELKA.VBAN.TestingTool.slnx -c Release

Create a self-contained single-file Windows x64 build:

dotnet publish .\ELKA.VBAN.TestingTool.App\ELKA.VBAN.TestingTool.App.csproj -c Release -r win-x64 --self-contained true -p:PublishSingleFile=true -o .\publish\ELKA.VBAN.TestingTool-win-x64

The project targets .NET 8 WPF and uses the Divert.Windows NuGet package for passive packet capture. VoiceMeeter's VoicemeeterRemote64.dll is loaded from the user's normal VoiceMeeter installation and is not redistributed.

See Getting Started, Function and Data Reference, and Third-Party Notices.

Project status and licensing

This public repository is provided for inspection and testing. No open-source license has currently been granted for the ELKA source code. Third-party components remain under their own licenses as listed in THIRD_PARTY_NOTICES.md.

VoiceMeeter, VBAN, Matrix, and VB-Audio are names associated with VB-Audio Software. This project is a diagnostic companion and does not redistribute VoiceMeeter or Matrix.