In today’s data deluge era, short-distance rack interconnects are crucial for robust data center performance.
In modern data centers with ever-increasing computing density, short-distance interconnects between servers and switches are essential for massive data transmission. The 100G QSFP28 SR4 optical module is designed to meet these technical and economic needs, making it an ideal solution for intra-data center links.
Faced with increasingly diverse requirements, there are two main solutions: traditional optical modules using individual optical fibers and integrated active optical cables. Each solution has unique characteristics that determine its applicable application scenarios.
QSFP28 SR4 Technical Architecture
The QSFP28 SR4 employs advanced 4x25G NRZ parallel transmission technology, enabling high data rates over multimode fiber. This architecture is based on spatial multiplexing of four independent optical channels, each operating at a rate of 25 Gbps.
This module uses 12 strands of MPO/MTP multimode fiber for connectivity, offering broad compatibility with OM3 and OM4 fiber types. A carefully designed mechanical structure ensures secure connector connections while facilitating installation and maintenance.
Its superior transmission performance allows for distances up to 70 meters on OM3 fiber and up to 100 meters on OM4 fiber, while consuming very little power, less than 2.5 watts. This high energy efficiency is particularly important in large data centers with high equipment density.
A key advantage of this solution is its operational flexibility—the module can be decoupled from the fiber, allowing for precise tailoring to the specific needs of each infrastructure. This modular design also facilitates maintenance and future network upgrades.
Comparative Analysis with Active Optical Cables
Active Optical Cables (AOCs) represent a unique alternative. They offer integrated solutions with factory-installed transceivers at the cable ends and ensure optimal performance through precise calibration in a controlled environment.
From a technical perspective, these cables have slightly lower power consumption (below 2.2W) and offer the advantage of being plug-and-play. Installation is simple and requires no advanced fiber optic technology.
AOC’s sealed design makes them more resistant to environmental contamination, significantly reducing the risk of performance degradation due to connector contamination. This robustness translates to higher reliability in harsh environments.
However, this integration also has the disadvantage of reduced flexibility—since the length is fixed during manufacturing, any infrastructure changes may require replacing the entire cable.
Specialized Applications
In today’s data center ecosystem, the QSFP28 SR4 excels in several key application scenarios:
Connections between servers within the same rack or adjacent racks directly benefit from the high performance and low latency offered by this technology.
Interconnecting higher-level switches achieves an ideal balance of performance, cost, and reliability in this solution.
Connections to storage devices in virtualized environments require the stability and consistent throughput provided by SR4.
The modular architecture simplifies maintenance and offers superior scalability, a stark contrast to more restrictive integrated solutions.
Development Prospects and Trends
With the advent of 400G and 800G, the transition to higher data rates is accelerating. However, the QSFP28 SR4 remains significant due to its mature technology and unparalleled cost-effectiveness in 100G applications.
Recent development focuses on improving energy efficiency and reducing size, thereby enabling increasingly higher integration density in server racks.
The SR4 ecosystem continues to expand with the emergence of compatible components and integrated management solutions, extending its lifespan in network infrastructure.
Conclusion
The choice between SR4 and AOC ultimately comes down to a trade-off between several criteria: flexibility and cost control (SR4) versus ease of deployment and reliability (AOC). Each technology has its place in modern data center environments, depending on the specific constraints of each project.
As we enter an era of AI and machine learning-accelerated computing, these interconnect technologies will continue to evolve, but QSFP28 SR4 remains a proven and reliable solution for modern network infrastructure.
As the digital world moves towards higher data rates, 100G QSFP28 SR4 offers the optimal balance between performance, cost, and flexibility for short-range interconnects—a key bridge to the future of communications, demonstrating that technological maturity remains a valuable asset in a rapidly changing environment.