An open network-measurement project
Pathrate is building a distributed way to quantify the quality of your network path to the internet — not the throughput of one TCP flow to a nearby test server, but the actual capacity and condition of the links your traffic crosses.
Δ = L/C, carries the capacity of the narrow link.
No router cooperation, no saturating the line. The path measures itself.
A bulk-transfer speed test measures one thing: how fast a TCP flow ran to a well-connected server, right then, competing with everything else on your line. It cannot distinguish a slow link from a busy one, and it floods the path to find out.
Packet-dispersion techniques probe with pairs and short trains of packets and read the time structure of what arrives. The dispersion distribution separates capacity — what the narrow link could do — from the effects of cross traffic — what everyone else is doing on it. Long trains yield a third quantity, the average dispersion rate, that brackets the truth from both sides:
Run that from many vantage points, continuously and cheaply — the probing load is kilobits per second, not a flood — and you get something a speed test can never give you: a quantified, comparable picture of path quality across your network and out to the internet.
You can't install software on every device you care about. Pathrate degrades honestly: each mode states what it can and cannot know.
A pathrate agent at each end: UDP probe trains, one-way dispersion measured at the receiver with kernel timestamps, plus iperf-class throughput checks. The full methodology.
yields: capacity · ADR · loss · full path map
Probing a live TCP or UDP service plus ICMP. Dispersion is inferred from protocol replies, so the reverse path is in every number — reported as an indication, never dressed up as a measurement.
yields: capacity estimate · RTT · loss
Back-to-back echo trains against a device you can only ping. Bounds the round-trip narrow link and characterizes latency, jitter, and loss — with the confidence honestly marked down.
yields: bounded estimate · RTT · jitter · loss
The methodology comes from the literature that named this domain: packet-pair and packet-train dispersion, multimodal mode detection, and ADR-filtered capacity estimation as implemented in the original pathrate tool. This project is an independent, open-source continuation of that line of work, not affiliated with the original authors.