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TraceFixture Deterministic Packet Fixture Packs

Source: this release’s synthetic input → 6 output files. Observed 2026-09-08. 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.

Open the workflow Download example

Construct loss and duplication capture fixtures for offline tests

Free browser processingNo account requiredDownloadable resultsExplicit supported scope

YOUR WORKSPACE

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.

Open JSON file Input template

Your input · JSON, up to 8 MiB

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.

HOW TO USE IT

A repeatable input-to-output workflow

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

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

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.

OPTIONAL OFFLINE BATCH KIT

TraceFixture automation kit

$299 one time

Proposed 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. Checkout is unavailable at publication until a provider connection is established.

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

Checkout is unavailable. You can use the browser workflow now. The kit cannot be purchased on this page yet.

A future 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.

The interest page accepts contact details. Do not send your source files.

Inspect the synthetic example

Input and actual engine output, available before any purchase.

Example provenance: synthetic source fixture, generated and checked on 2026-09-08. The following sizes and hashes are counted from the downloadable result ZIP; they are not customer data or performance claims.

File in example	Bytes	SHA-256 prefix
README.md	1,090	8e62f954343c
baseline.manifest.json	620	2e7506a380fe
baseline.pcap	144	06ae3eb6c24d
loss.manifest.json	613	e6c3bbb95c42
loss.pcap	144	8449c67a1a2c
verifier.py	11,109	9583e863a544

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.