QSFP-100G-CU3M=

The QSFP-100G-CU3M is a passive copper cable for 100 Gigabit Ethernet, 3 m long, with a QSFP28 connector at each end. The rate is fixed by the cable type, so the port at each end must be set for the matching speed. Neat hook-and-loop strapping helps keep front-to-back airflow clear around the switch faceplate. Keep a spare of the same length on the shelf if the link is critical, as there is no field repair for a moulded cable. It links two QSFP28 ports directly; the passive build means very low power draw and no digital diagnostics. Cisco's 100GBASE QSFP-100G data sheet lists it as a 100GBASE-CR4 direct-attach cable carrying four 25G lanes each way. The twinax bundle is thicker and stiffer than 10G or 25G cables, so leave room for a gentle bend at each connector. Hot-swap behaviour follows the host port, and the link normally comes up once both ends are seated. The length gives some freedom in equipment placement, so the switch need not sit in the exact middle of the rack.