Cisco QSFP-100G-CU0.5M Compatible 100G QSFP28 4 x 25G NRZ Passive Copper Twinax Cable, 0.5m (2ft)

Product Highlights

• Compatible alternative to Cisco QSFP-100G-CU0.5M
• 100G connectivity at 100Gbps
• Interface configuration: QSFP28 to QSFP28
• Fixed length and part number: 0.5m (2ft), QSFP-100G-CU0.5M
• 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 0.5m (2ft) length is suited to closely aligned ports where excessive slack would obstruct airflow or complicate dressing. Measure the actual port-to-port path before choosing QSFP-100G-CU0.5M; even a short assembly must retain the specified bend radius and should never be pulled tight behind the equipment.

Position Within the Length Range

QSFP-100G-CU0.5M is the shortest of 7 verified length options in this family. It is the preferred choice when the port positions are close and cable slack must be kept to a minimum. The next option is QSFP-100G-CU1M at 1m (3ft), adding 0.5m for a less direct routing path; selecting it unnecessarily would leave more cable to dress.

High-Density Rack Integration

In a densely populated rack, connector access and airflow are part of the link design. Choose the shortest length that follows the managed path comfortably, avoid tight bundles around the connector housings and preserve room for latch operation. Where power consumption is listed, include every populated interface in the host thermal budget rather than assessing a single cable in isolation. 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.

Quality Assurance and Packaging

Each assembly receives a visual connector inspection and functional link check before it is coiled and protected. Packaging is selected to avoid compressing the cable into a tight bundle, and optional rack-based labels help maintain an orderly installation when many identical interfaces are populated together. Neutral packaging and customer-specific packing documentation are available on request.

Ordering Information

Provide the exact part number, length, quantity and target interface density. For multi-rack projects, list each length separately and identify any preferred carton grouping. Host model and software information can be included for a compatibility review before production or dispatch. Quantity and any labeling instructions should be attached specifically to QSFP-100G-CU0.5M.

Cisco Compatibility and Factory Testing

The assembly is evaluated for host recognition and stable link operation, with diagnostics checked where the interface provides them. This approach verifies more than electrical or optical continuity. Exact platform and firmware information remains valuable in high-density deployments because port mode and qualification policy can differ within the same connector family. The check includes link stability and diagnostic indications, followed by a final inspection of both ends.

Frequently Asked Questions

Shipping and Lead Time

Standard configurations normally ship within one to three working days, with production quantities confirmed at order stage. Worldwide courier services are available, with air or sea freight for consolidated shipments; freight-collect delivery and coordination with a customer’s logistics provider can be arranged.