The QSFP28 full-duplex optical module offers 4 independent transmit and receive channels, each capable of 25Gb/s operation for an aggregate data rate of 100Gb/s on 100 meters of OM4 multi-mode fiber. Cisco® QSFP28 100G ZR extends 100GbE coherent links from QSFP28 ports reaching up to 80km over dark fiber and up to 300km over amplified Dense Wave Division Multiplexing (DWDM) links. The 100G QSFP28 module solution provides high-performance 100GbE connectivity for data centres, enterprise core & distribution layers, computing networks and service provider applications. It provides increased port density and total system cost savings. Dispersion/path penalties not taken into account.