Cisco QDD-400G-DR4-S

The Cisco QDD-400G-DR4-S is a high-speed, high-density optical transceiver module designed for data center and enterprise networking applications. It is part of Cisco's portfolio of 400 Gigabit Ethernet (400G) transceivers. The "QDD" in the product name stands for Quad Small Form Factor Pluggable Double Density, indicating that it is a compact form factor transceiver. The "400G" refers to its data rate capability of 400 Gigabits per second. The "DR4" in the product name stands for Dense Wavelength Division Multiplexing (DWDM) 4-lane, which means it uses four optical lanes to transmit and receive data. Each lane operates at a speed of 100 Gigabits per second, resulting in a total data rate of 400G. The "S" at the end of the product name indicates that it is a single-mode transceiver, designed for use with single-mode fiber optic cables. Overall, the Cisco QDD-400G-DR4-S is a high-performance transceiver module that enables high-speed data transmission over long distances in data center and enterprise networking environments.