AEC · Active Electrical Cable
Copper cable with a redriver or retimer in the connector, buying a few metres of reach past passive DAC at a power and reliability cost; it sets the distance where optics become unavoidable.
Current numbers
~1–2 m DAC; up to 7 m AECcopper reach at 800G-class rates: passive DAC vs AEC, optics beyond — verify the channel at 224G/lane