The Cisco QSFP-100G-FR-S Module supports link lengths of up to 2 km over a standard pair of G.652 Single-Mode Fiber (SMF) with duplex LC connectors. The QSFP-100G-FR-S module is compliant to IEEE 802.3 100GBASE-FR1 requirements. The 100 Gigabit Ethernet signal is carried over a single wavelength using onboard PAM4 modulation and FEC. QSFP-100G-FR-S can also be used in applications meant for IEEE 100GBASE-DR, such as interoperability with IEEE 400GBASE-DR4 via fiber break-out cables.