The Cisco® 40GBASE CFP transceiver modules are hot-swappable input/output devices that plug into a 40 Gigabit Ethernet CFP port of a Cisco switch or router. They offer customers versatile 40 Gigabit Ethernet connectivity options in core and distribution layers of data center, enterprise, and service provider networks.The Cisco 40GBASE-LR4 CFP module (Figure 2) supports link lengths of up to 10km over a standard pair of G.652 single-mode fiber with duplex SC connectors. The 40 Gigabit Ethernet signal is carried over four wavelengths. Multiplexing and demultiplexing of the four wavelengths are managed within the device. This CFP module supports both IEEE 40GBASE-LR4 and OTU3 C4S1-2D1 standards.