The Cisco QSFP-40G-SR-BD is a transceiver module designed for use in high-speed data communication networks. It is a Quad Small Form-factor Pluggable (QSFP) module that supports data rates of up to 40 Gigabits per second (Gbps).
The "SR" in the product name stands for "short reach," indicating that it is designed for short-distance transmission. The "BD" stands for "bi-directional," meaning that it supports transmission and reception on a single fiber strand.
The QSFP-40G-SR-BD module uses a multi-mode fiber optic cable and operates over a distance of up to 100 meters. It is commonly used in data centers and other high-performance computing environments for applications such as server connectivity, switch-to-switch connectivity, and storage area networks.