# cabletest docs

Project knowledge that moves and versions with the repo.

cabletest finds Ethernet cables that misbehave under sustained full-duplex 10 Gbit load. It exchanges raw Ethernet frames (no IP, no ARP) across a variety of sizes and payloads between two directly-cabled ports on one host, and attributes every problem it can to the cable rather than the host. It runs as PID 1 on a dedicated appliance with a framebuffer UI; development happens on the same machine under Arch. The target of measurement is the cable, not throughput — line rate is a means to stress the physical layer.

General:

- [state.md](state.md) — where things are now: the box and what's in it, the bench driver, every-boot steps. **All current-placement state lives here and only here.**
- [hardware.md](hardware.md) — host rules: interface conventions, tuning, how to run.
- [measurement.md](measurement.md) — how to measure correctly; performance results and dead ends.
- [xdp.md](xdp.md) — the AF_XDP datapath experiment: what it proved, what rebuilding it needs, why it can't run on the X520.

Per-device (each directory: device doc + its datasheets):

- [nics/](nics/README.md) — the transport rule, the comparison table, and one directory per NIC: [x520](nics/x520/README.md), [connectx-5](nics/connectx-5/README.md), [x710](nics/x710/README.md), [e810](nics/e810/README.md).
- [modules/](modules/README.md) — module inventory, media-lies table, the shared IEEE register set, RollBall protocol, cable-length physics, and one directory per module: [fs](modules/fs/README.md), [wiitek](modules/wiitek/README.md), [fibergaga](modules/fibergaga/README.md).