InfiniBand/fibre optic cable BlueOptics 845408-B21-BL 5 m QSFP28 Male/Male

The BlueOptics 845408-B21-BL is a 5 m InfiniBand/fibre optic direct attach cable with QSFP28 connectors on both ends. Designed for short-range high-speed links, this passive QSFP28-to-QSFP28 cable supports 100G data rates and is intended for use in rack and adjacent-rack connections in data centers and networking environments. Its male/male QSFP28 terminations provide straightforward insertion into compatible 100G ports on switches, routers and storage systems that accept QSFP28 direct attach twinax or electrically compatible connections.

Advantages

This 5 m BlueOptics cable offers a compact, low-latency connection option for short-distance links with support for 100GBase-CR4, InfiniBand and other high-speed protocols. As a passive direct attach solution, it requires no external power or transceiver modules, reducing power consumption and simplifying deployment. The cable is manufactured to industry MSA guidelines and uses robust QSFP28 connectors to ensure mechanical stability and reliable electrical contact in high-density rack installations.

Key specifications

• Cable length: 5 m
• Connector type: QSFP28 to QSFP28, male/male
• Supported link rate: up to 100 Gbit/s
• Physical medium: passive twinax / electrically coupled direct attach
• Wire gauge: 26 AWG (as used in industry-standard twinax DACs)
• Compatible protocols: 100GBase-CR4 Ethernet, Fibre Channel, FCoE and InfiniBand (where supported)
• Intended use: short-range rack and adjacent-rack cabling

How to use

Install the cable by inserting each QSFP28 plug into the corresponding QSFP28 port until the latch engages. Confirm that connected devices support passive QSFP28 direct attach twinax connections and the intended protocol (for example, 100GBase-CR4 or InfiniBand). After physical connection, verify link status and negotiated speed in the device management interface. For best results, route the cable to avoid sharp bends and mechanical strain on the connectors.

Recommendations

Use this 5 m passive QSFP28 cable for short-distance interconnects where low latency, low power consumption and predictable electrical performance are required. Ensure both endpoints explicitly support passive DACs and the chosen protocol. Avoid exceeding the specified bend radius and protect the cable from excessive pulling or crushing to maintain long-term reliability.