Optical QSFP Transceiver BlueOptics BO25K859S3D 40GBASE-ESR4 Multimode Fiber

BlueOptics BO25K859S3D is a QSFP optical transceiver module engineered for 40GBASE-ESR4 multimode fiber links. It occupies a compact QSFP form factor and supports four parallel lanes to deliver aggregate 40 Gbit/s throughput for short-reach multimode applications. The module is intended for use in data center and enterprise aggregation, switch-to-switch uplinks, and high-density fiber patch deployments where reliable, hot-pluggable 40 Gb/s connectivity is required.

Advantages

The transceiver offers a compact QSFP design that enables high port density in switches and routers, while supporting multimode fiber to keep link costs and cabling complexity lower for short distances. Hot-pluggable operation simplifies installation and replacement without powering down equipment. Designed for 40GBASE-ESR4 operation, it provides stable aggregate throughput across the four parallel lanes and is compatible with common multimode fiber cabling practices used in datacenter environments.

Suitable for

Key specifications

How to use

Insert the QSFP transceiver into a compatible QSFP port on a switch or router until it seats firmly; avoid excessive force. Connect an MPO/MTP parallel multimode fiber cable between the transceiver and the remote device or patch panel, ensuring correct fiber polarity and that the fiber type (OM3/OM4) matches the intended distance. After physical installation, verify link status in the host device management interface and ensure the port speed and lane configuration are set for 40GBASE-ESR4 operation. Handle the module by its edges and keep dust caps on fiber connectors when not in use to prevent contamination.

Recommendations

Use this QSFP transceiver with high-quality OM3 or OM4 multimode fiber and MPO/MTP trunk cables for reliable short-reach 40G links. Ensure proper cable polarity and cleanliness during installation, and confirm compatibility with the host equipment's QSFP interface and firmware to avoid interoperability issues.