Network Cable BlueLAN Cumulus QSFP28-4SFP28-DAC-2M 100GBASE-CR4 2m Blue

The BlueLAN Cumulus QSFP28-4SFP28-DAC-2M is a passive direct-attach breakout cable engineered for short-reach, high-bandwidth connectivity in network infrastructure. It combines a single QSFP28 plug with four SFP28 plugs to deliver 100GBASE-CR4 to 4x25GBASE-CR operation over a 2 meter twinax assembly. Constructed with AWG26 conductors and designed for low insertion loss and controlled impedance, this cable is intended for interconnecting switches, routers and server ports within racks and across adjacent racks in data center and high-performance computing deployments.

Advantages

The cable provides a compact, low-latency solution for aggregating 25 Gbps lanes into a 100 Gbps QSFP28 interface without active electronics. Passive twinax construction reduces power consumption compared with active optics and simplifies deployment by eliminating separate transceivers. With a 2 m length and AWG26 gauge, it balances flexibility and signal integrity for short-reach links while keeping weight and connector strain low. The breakout arrangement allows direct connection to four SFP28 ports from a single QSFP28 port, streamlining port mapping and cabling density.

Suitable for

• Inter-rack and intra-rack connections between switches and spine/leaf architectures
• Server to top-of-rack switch links requiring 100G to 4×25G breakout
• High-performance computing clusters and storage network aggregation
• Environments where passive, low-power short-reach cabling is preferred

Key specifications

• Connector configuration: QSFP28 to 4 × SFP28
• Supported standards: 100GBASE-CR4 to 4×25GBASE-CR
• Cable type: Passive twinax direct attach cable (DAC)
• Length: 2 meters
• Wire gauge: AWG26
• Typical use case: Short-reach data center interconnects

How to use

Insert the QSFP28 connector into the 100G QSFP28 port and align each of the four SFP28 connectors with their respective 25G SFP28 ports. Ensure connectors are fully seated and retention latches are engaged. Route the cable to avoid sharp bends and excessive tension; maintain the minimum bend radius specified by the equipment manufacturer. No external power or configuration is required for passive operation, but confirm that connected devices support breakout from QSFP28 to SFP28 ports and have compatible lane mapping and firmware settings.

Usage recommendations

Use this cable for short-distance, high-bandwidth links inside racks or between adjacent racks. Verify compatibility with switch and server vendor breakout support and follow ESD handling procedures when plugging or unplugging. Avoid running the cable near high-interference sources and keep cable runs within the recommended 2 m length to maintain signal integrity.