QDD-400-AOC25M=

The QDD-400-AOC25M is a 400 Gigabit active optical cable, 25 m long, with a QSFP-DD connector on each end and multimode fibre between them. Cisco's 400G QSFP-DD data sheet lists it in the QDD-400-AOC family, from 1 m to 30 m, with forward error correction handled by the host platform. Laying the cable in before the equipment is fully racked leaves the final connection for last and saves rework. Handle it by the connector bodies, keep the bend radius generous, and avoid tight ties that squeeze the jacket. Hot-swap behaviour follows the host port, and the link normally comes up once both ends are seated. Because it is built to a set length, stock planning is by length, so a rack plan listing each link helps ordering. It serves links across a data hall where the two devices sit far apart and the cable path is long. The fibre jacket is far lighter and more flexible than 400G copper, which matters in dense spine-leaf rows. The optics are sealed in the connector bodies, so there is no MPO connector to clean and no transceivers to pair.