Cisco SFP-H25G-CU1M
25GBASE-CU SFP28 Cable 1 Meter, Original Cisco
Product Highlights
As data center traffic scales beyond 10G, network engineers need a reliable, low-latency interconnect that delivers 25 Gigabit Ethernet performance without the cost and complexity of optical transceivers. The Cisco SFP-H25G-CU1M is a genuine Cisco 25GBASE-CU SFP28 passive direct attach copper (DAC) twinax cable assembly with a 1-meter reach, purpose-built for short-distance, high-speed links within and between adjacent racks.
This passive copper cable features SFP28 connectors on both ends that hot-plug directly into any compatible SFP28 port, eliminating the need for separate transceiver modules and fiber patch cords. With no active electronic components, the SFP-H25G-CU1M draws minimal power and delivers an inherently reliable point-to-point 25G connection — ideal for server-to-leaf switch uplinks, storage fabric interconnects, and high-performance computing clusters.
Compliant with IEEE 802.3by and SFP28 MSA standards (SFF-8402), this Cisco DAC cable supports 25GBASE-CR1 Ethernet and is compatible with Cisco switches and routers equipped with SFP28 ports. The cable also supports FCoE with appropriate host software. Whether you're building out a new 25G leaf-spine fabric or upgrading from 10G, the SFP-H25G-CU1M delivers the bandwidth you need at a fraction of the cost of optical solutions.
Features & Benefits
Passive Copper — Maximum Simplicity
The SFP-H25G-CU1M uses passive twinax copper construction with no active electronic components or lasers. This means near-zero power draw, no heat generation from optics, and one less failure point in your link. For short-distance connections up to 1 meter, passive DAC cables are the most cost-effective and reliable interconnect option available.
25G Performance for Modern Data Centers
Supporting 25 Gbps data rates over 25GBASE-CR1, this cable delivers 2.5× the bandwidth of 10G SFP+ links on a single lane. It is an ideal building block for leaf-spine architectures, server uplinks, and storage networks that demand more throughput without jumping to 40G or 100G infrastructure.
Standards-Based Interoperability
The cable is compliant with IEEE 802.3by for 25 Gigabit Ethernet and adheres to the SFP28 Multi-Source Agreement (SFF-8402). Each SFP28 connector includes an EEPROM that provides product identification data readable by the host system, ensuring seamless integration and monitoring.
Hot-Pluggable SFP28 Form Factor
Both ends of the cable feature standard SFP28 connectors that hot-plug into SFP28 cages without powering down the device. This enables non-disruptive deployment and replacement, reducing maintenance windows and simplifying day-two operations in production environments.
FCoE Support
Cisco's 25G DAC cables, including the SFP-H25G-CU1M, support Fibre Channel over Ethernet (FCoE) with appropriate host software. This makes the cable suitable for converged network environments where both Ethernet and storage traffic share the same physical infrastructure.
Deployment Scenarios
Top-of-Rack Server Uplinks
Connect servers with 25G NICs directly to leaf switches within the same rack. The 1-meter passive DAC cable provides the lowest-latency, lowest-cost 25G link for dense server environments where every watt and dollar counts.
Leaf-to-Spine Fabric Interconnects
In compact leaf-spine topologies where switches are co-located in the same or adjacent racks, the SFP-H25G-CU1M provides a reliable 25G fabric link without the expense of optical transceivers and fiber patch cords.
Storage Area Network (SAN) Connectivity
Use the cable to interconnect storage arrays and SAN switches at 25G speeds. With FCoE support, it fits neatly into converged data center designs that unify LAN and SAN traffic on a single Ethernet fabric.
High-Performance Computing (HPC) Clusters
Link compute nodes within HPC clusters where low latency and high bandwidth are critical. The passive copper design minimizes signal processing delay, making it well-suited for latency-sensitive parallel computing workloads.
General
Performance
Physical
Environmental
Compliance
Compatibility Notes
The Cisco SFP-H25G-CU1M is designed for use in Cisco switches and routers equipped with SFP28 ports supporting 25GBASE-CR. Always verify compatibility for your specific platform and software version using the Cisco Transceiver Module Group (TMG) Compatibility Matrix. The cable supports FCoE with appropriate host software support.
Downloads & Resources
Frequently Asked Questions
| Part Number | Product | Key Difference |
|---|---|---|
| SFP-H25G-CU3M | Cisco 25G SFP28 DAC 3M | Same passive DAC technology but with 3-meter reach for connections spanning adjacent racks. |
| SFP-H25G-CU5M | Cisco 25G SFP28 DAC 5M | Maximum-length 25G passive DAC at 5 meters for longer inter-rack runs. |
| SFP-25G-AOC1M | Cisco 25G SFP28 AOC 1M | Active optical cable alternative — uses fiber optics instead of copper for lower EMI in dense environments. |
| SFP-25G-SR-S | Cisco 25G SFP28 SR Transceiver | Pluggable optical transceiver for multimode fiber runs up to 100m (OM4) — choose when distance exceeds DAC reach. |
