Cisco QSFP-100G-CUxM:
Cisco QSFP to QSFP copper direct-attach 100GBASE-CR4 cables are suitable for very short links and offer a cost-effective way to establish a 100-Gigabit link between QSFP-100G ports of Cisco switches within racks and across adjacent racks. Cisco currently offers passive copper cables in lengths of 1, 2, 3 and 5 meters.
Cisco QSFP-100G-AOCxM:
Cisco QSFP-100G to QSFP-100G AOC cables are suitable for short distances and offer a flexible way to connect within racks and across racks. Active optical cables are much thinner and lighter than copper cables, which makes cable management easier. AOCs enable efficient system airflow, which is critical in high-density racks. Cisco currently offers active optical cables in lengths of 1, 2, 3, 5, 7, 10, 15, 20, 25, and 30 meters.