The Cisco QSFP-100G-ERL-S Module supports link lengths of up to 25 km over a standard pair of G.652 Single-Mode Fiber (SMF) with duplex LC connectors. The 100 Gigabit Ethernet signal is carried over a single wavelength using onboard PAM4 modulation and FEC. It complies with the 100G LR1-20 standard and interoperates with other transceivers meeting that standard up to 20km.