Cisco QSFP-4SFP25G-CU1M Compatible 100G QSFP28 4 x 25G NRZ to 4 x 25G SFP28 NRZ Passive Copper Breakout Cable, 1m (3ft)

Product Highlights

• Compatible alternative to Cisco QSFP-4SFP25G-CU1M
• 100G connectivity at 100Gbps
• Interface configuration: QSFP28 to SFP28
• Fixed length and part number: 1m (3ft), QSFP-4SFP25G-CU1M
• Cable construction: Passive Twinax
• Conductor specification: 30AWG
• Maximum power consumption: ≤0.125W
• Minimum bend radius: 60mm

Specifications

Cisco OEM Reference

Cisco defines QSFP-4SFP25G-CUxM as a 100G QSFP to four 25G SFP passive copper breakout assembly. One end connects to a 100G QSFP port and the four branches connect to 25G interfaces on a switch or server. Correct channelization and lane mapping are essential for this HT compatible version as well.

Breakout Port Mapping

The QSFP28 to SFP28 configuration divides the high-speed interface into multiple lower-speed connections. Verify the upstream lane assignment, downstream port speeds and breakout setting on the host before connecting the assembly. Each branch must attach to the correct remote interface.

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

At 1m (3ft), QSFP-4SFP25G-CU1M is a practical choice for direct connections within one rack. Route the cable along the intended management path rather than pulling it diagonally across adjacent connectors, and leave enough clearance for insertion, removal and front-panel airflow.

Position Within the Length Range

QSFP-4SFP25G-CU1M occupies the middle of this family between QSFP-4SFP25G-CU50CM at 0.5m (2ft) and QSFP-4SFP25G-CU1-5M at 1.5m (5ft). 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.

Rack Layout and Service Access

Plan the managed route before removing the connector protection. The cable should reach both ports without tension while leaving enough space to release the latches and service adjacent interfaces. Support the run through the intended managers, keep the connector boots clear of sharp edges and avoid storing excess length in a tight coil behind warm exhaust air. For this assembly, the listed conductor specification is 30AWG; the minimum bend radius is 60mm; the stated power consumption is ≤0.125W; the jacket material is PVC (OFNR).

Signal and Lane Configuration

The listed modulation format is QSFP28-4x 25G-NRZ SFP28-1x 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 ≤0.125W. 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 60mm. 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 to 4x 25G Ethernet, Data Centers. Listed interface and protocol references include IEEE 802.3, QSFP28 MSA, SFF-8665. Confirm that the host firmware and port configuration support the same operating mode.

Quality Assurance and Packaging

The completed cable is inspected at both ends, functionally tested and coiled with bend-safe slack. Protective packaging keeps the latches and boots from taking impact, while optional project labels can identify the two endpoint locations for easier field service. Standard protective packing is used by default, with project documentation arranged when requested.

Cisco Compatibility and Factory Testing

Compatibility is verified as part of a complete installation check: connector inspection, host identification and an operating link. The physical cable is evaluated together with the expected OEM identity, because a connector that fits is not sufficient evidence that the host will accept and operate the assembly correctly. Where supported by the host, link stability and diagnostic indications are reviewed together with the established link.

Frequently Asked Questions

Ordering Information

When requesting this assembly, include the exact part number and length together with the destination port types. For a rack installation, a simple port-to-port list helps us keep different lengths separate and allows any requested labels to correspond with the actual installation sequence. This page’s fixed configuration is 1m (3ft); another length must be quoted under its corresponding part number.

Shipping and Lead Time

Standard configurations normally ship within one to three working days, while production quantities are confirmed with the order. 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.