The MTU, from 576 to 9000, on the three-appliance bench
Measured 2026-10-17 on the bench: one TCP stream for ten seconds in each
direction, in clear text and through the IPsec tunnels (AES-GCM-256, in the engines at both ends),
at eight MTUs from the smallest to the largest. Every run's window was photographed when it
finished; the 52 pictures are in docs/images/measurements/mtu-2026-10-17/ and below each table.