Cisco QSFP-100G-CU2.5M Compatible 100G QSFP28 4 x 25G NRZ Passive Copper Twinax Cable, 2.5m (8ft)

Product Highlights

• Compatible alternative to Cisco QSFP-100G-CU2.5M
• 100G connectivity at 100Gbps
• Interface configuration: QSFP28 to QSFP28
• Fixed length and part number: 2.5m (8ft), QSFP-100G-CU2.5M
• Cable construction: Passive Twinax
• Conductor specification: 30AWG
• Maximum power consumption: ≤0.5W
• Minimum bend radius: 33.5mm

Specifications

Cisco OEM Reference

Cisco classifies the QSFP-100G-CUxM family as 100GBASE-CR4 passive copper direct-attach cable for very short links within racks and between adjacent racks. Its documented family includes 1m, 1.5m, 2m, 2.5m, 3m and 5m part numbers. This HT page covers the exact length and OEM reference shown above; the compatible assembly itself follows the HT specification table.

Passive Copper Operation

A passive DAC has no separate optical conversion stage. Its low-power, low-latency operation is useful for short equipment links, but the assembly must remain within the length and signaling mode accepted by both hosts.

Length Selection and Installation Planning

The 2.5m (8ft) version is useful when a two-metre run would leave insufficient working slack. Before installation, check the complete horizontal and vertical path so that QSFP-100G-CU2.5M reaches both ports without tension at either connector.

Position Within the Length Range

QSFP-100G-CU2.5M occupies the middle of this family between QSFP-100G-CU2M at 2m (7ft) and QSFP-100G-CU3M at 3m (10ft). It adds 0.5m over the shorter option for extra routing clearance, while the next longer version adds another 0.5m. Measure the managed path and choose this version when its reach is sufficient without creating the slack associated with the longer assembly.

Interoperability and Configuration Checks

Check three layers before deployment: the host must accept the cable identification, the port must support the stated aggregate rate, and the lane configuration must match the attached interfaces. On breakout hardware, also confirm channelization and the mapping of every branch. These checks are particularly important when similar-looking ports operate at different speeds or under different firmware settings. For this assembly, the listed conductor specification is 30AWG; the minimum bend radius is 33.5mm; the stated power consumption is ≤0.5W; the jacket material is PVC (OFNR).

Signal and Lane Configuration

The listed modulation format is 4x 25G-NRZ to 4x 25G-NRZ. Both host interfaces must be configured for the same aggregate rate and lane arrangement. A connector that fits mechanically does not by itself guarantee that the remote port supports this encoding or breakout mode.

Power and Thermal Planning

The rated power consumption is ≤0.5W. Include this load in the host-port power and thermal budget, especially in densely populated switches. Maintain front-panel clearance and do not bundle the cable so tightly that it obstructs airflow around the connectors.

Cable Construction and Routing

This assembly uses 30AWG conductors, PVC (OFNR) jacket, minimum bend radius 33.5mm. These mechanical characteristics affect how the cable should be dressed behind the equipment. Avoid sharp edges, excessive ties and repeated tight bends close to the connector boots.

Network and Protocol Considerations

The intended application is 100G Ethernet. Listed interface and protocol references include QSFP28 MSA, SFF-8662, IEEE 802.3. Confirm that the host firmware and port configuration support the same operating mode.

Ordering Information

Specify the OEM part number and fixed length, then provide the intended host configuration if the link uses channelized or breakout ports. Separate part numbers should be used for separate lengths. This gives the compatibility review enough information to check both the physical assembly and the intended operating mode. Quantity and any labeling instructions should be attached specifically to QSFP-100G-CU2.5M.

Cisco Compatibility and Factory Testing

The verification process combines digital identification with a live link test and diagnostic observation. Host model, hardware revision and software release are useful inputs because qualification behavior can change between platform generations; those details allow platform-specific requirements to be reviewed before the cable is packed. The check includes link stability and diagnostic indications, followed by a final inspection of both ends.

Shipping and Lead Time

Standard configurations normally ship within one to three working days, while production quantities are confirmed with the order. International express, air cargo and sea freight can be selected according to destination and carton volume; customer courier accounts and nominated forwarders are also accepted.

Quality Assurance and Packaging

Functional inspection covers identification, link establishment and the condition of both connector assemblies. The cable is then protected against dust and connector damage and packed without sharp bends. Labels can include the customer reference and host-platform note when requested for a controlled deployment. Standard protective packing is used by default, with project documentation arranged when requested.

Frequently Asked Questions