QSFP-4SFP25G-CU3M=

The QSFP-4SFP25G-CU3M is a passive breakout copper cable, 3 m long. Label both ends at installation, since cables of different lengths look identical in a dense rack. It spans a full rack and typically the adjacent rack as well, with room for a tidy loop in the vertical cable manager. The rate is fixed by the cable type, so the port at each end must be set for the matching speed. Because it is built to a set length, stock planning is by length, so a rack plan listing each link helps ordering. Cisco's 100GBASE QSFP-100G data sheet lists it in the passive copper breakout table. The switch port must be set to split into four 25G interfaces, and FEC settings should match on all four far-end ports. One end is a 100G QSFP28 connector, and the other splits into four SFP28 connectors, each carrying one 25 Gigabit Ethernet lane. Store unused lengths coiled loosely in their bag so the jacket and strain reliefs keep their shape.