US Tech Automations

Network software test teamsConstruct loss and duplication capture fixtures for offline testsExperimental offer

TraceFixture Deterministic Packet Fixture Packs

Source: this release’s synthetic input → 6 output files. Observed 2026-09-09. Coverage: one example within the supported profile.

TraceFixture constructs an Ethernet/IPv4/UDP PCAP from packets you declare, applying deterministic loss, duplication, and time scaling. It is meant for offline test suites that need a stable, repeatable capture to replay, rather than live traffic. Your supplied payloads are placed into the capture as given, so you control exactly what each fixture contains.

Browser workflow
Free to use
Optional batch kit
$299
Example output
6 files, 2026-09-09
Checkout
On Gumroad

Free to use. The workflow runs in your browser. The optional batch kit is sold on Gumroad.

Buy on Gumroad — $299Open the workflowDownload example

Free browser processingNo account requiredDownloadable resultsExplicit supported scope

A repeatable input-to-output workflow

  1. 01

    Declare your packets, payloads, and the loss, duplication, and time-scaling rules as JSON.

  2. 02

    The tool builds an Ethernet/IPv4/UDP PCAP applying those rules deterministically.

  3. 03

    You download the capture fixture to replay in your offline test tooling.

What you receive

  • A deterministic Ethernet/IPv4/UDP PCAP file
  • The applied loss, duplication, and time-scaling record
  • A manifest of packets included in the fixture

Supported scope and limits

  • Constructs files only; no network sending
  • No TCP support and no pcapng conversion
  • Supplied payloads are retained as given, not anonymized
  • Scope is limited to declared Ethernet/IPv4/UDP packets

Read the exact input profile and examples. Start with the supplied template; this release does not guess missing settings.

Turn your input into a checked artifact

Load the synthetic example to explore the format, or choose your own supported JSON file. Processing happens on this device. Your input is not uploaded. The first run downloads the processing engine.

Step 01

Load an input

Input template

Load an input to begin. Each workflow also has its own smaller domain limits.

Keep your original source. Unsupported inputs return an explanation. These workflows implement the stated mathematical or file-format checks; they do not establish physical performance, language quality or real-world reliability.

Optional offline batch kit

TraceFixture automation kit

$299 one time

One-time batch automation kit: a versioned ZIP with an offline CLI runner, the TraceFixture engine module, input fixtures, a verifier, and acceptance tests for constructing packet fixtures offline. No recurring updates or support are promised.

Browser processing and result downloads above are free. The kit bundles the same core engine with an offline command-line runner, synthetic fixtures, source, checksums and acceptance tests for repeated jobs.

You pay and download on Gumroad.

Buy on Gumroad — $299

Your purchase delivers the named version as a ZIP. No subscription, future updates, hosted storage or hands-on review is included. Pricing is an introductory offer experiment.

Email about the kit

Your email app opens a draft. Do not send source files.

Inspect the synthetic example

Input and actual engine output, available before any purchase.

Example provenance: synthetic source fixture, generated and checked on 2026-09-09. The following sizes and hashes are counted from the downloadable result ZIP; they are not customer data or performance claims.

File in exampleBytesSHA-256 prefix
README.md1,0908e62f954343c
baseline.manifest.json6202e7506a380fe
baseline.pcap14406ae3eb6c24d
loss.manifest.json613e6c3bbb95c42
loss.pcap1448449c67a1a2c
verifier.py11,1099583e863a544

Before you start

Does it send packets on the network?

No. It only constructs a capture file for offline replay in your own tooling.

Can it handle TCP or pcapng?

No. It builds Ethernet/IPv4/UDP PCAP only and does not convert to pcapng.

Reference material

These sources describe the surrounding formats and established tools. They do not endorse this product or prove demand for it.