QSFP 40G SR BD is a type of optical transceiver module that uses a Quad Small Form-factor Pluggable (QSFP) connector.

Cisco QSFP40G portfolio

Cisco QSFP-40G-SR-BD (40G BiDi)

The Cisco QSFP 40-Gbps BiDirectional (BiDi) transceiver (Figure 1) is a pluggable optical transceiver with a duplex LC connector interface for short-reach data communication and interconnect applications using MultiMode Fiber (MMF). The Cisco QSFP 40-Gbps BiDi transceiver offers customers a compelling solution that enables reuse of their existing 10 gigabit duplex MMF infrastructure for migration to 40 Gigabit Ethernet connectivity.

The Cisco QSFP 40-Gbps BiDi transceiver supports link lengths of 100 and 150 meters on laser-optimized OM3, and OM4/OM5 multimode fibers, respectively.

The Cisco BiDi transceiver complies with the QSFP MSA specification, enabling customers to use it on all QSFP 40-Gbps platforms to achieve high-density 40 Gigabit Ethernet networks.

Each Cisco QSFP 40-Gbps BiDi transceiver consists of two 20-Gbps transmit and receive channels in the 832-918 nanometer wavelength range, enabling an aggregated 40-Gbps link over a two-strand multimode fiber connection.