QSFP28 Optical Module Applications

The QSFP28 optical module is used to enable high-speed 100G data transmission in data centers, enterprise networks, and high-performance computing environments.

Overview

QSFP28 (Quad Small Form-Factor Pluggable 28) is a compact, hot-swappable optical transceiver designed to support 100 Gigabit Ethernet (100GbE) by aggregating four parallel electrical lanes, each operating at 25 Gbps NRZ signaling, resulting in a total throughput of 100 Gbps . The “28” in QSFP28 refers to the maximum 28 Gbaud signaling rate per lane, providing sufficient overhead for error correction and clocking . Its form factor is backward-compatible with QSFP+ (40G) ports, allowing network devices to upgrade bandwidth density without redesigning front panels .

Key Uses

1. High-Speed Data Transmission QSFP28 modules convert four electrical lanes into optical signals, enabling 100G connectivity over multimode or single-mode fiber. Variants like SR4, LR4, and CWDM4 support different distances and fiber types, from short-reach data center links to long-haul metro connections .
2. Data Center and Cloud Infrastructure QSFP28 is widely deployed in spine-leaf architectures and hyperscale data centers, providing high port density and efficient bandwidth utilization. It allows operators to scale network capacity while maintaining low power consumption and compact module size .
3. Flexible Deployment Options The module supports breakout configurations, where a single 100G port can be split into four 25G connections, offering flexibility for connecting servers, switches, or storage devices . It also supports Digital Diagnostic Monitoring (DDM) for real-time monitoring of temperature, voltage, and optical power .
4. Long-Haul and Coherent Optics Applications Advanced QSFP28 variants, such as the 100G ZR digital coherent optics module, extend 100G links up to 80 km over dark fiber and up to 300 km over amplified DWDM networks. These modules are ideal for metro access, data center interconnects, and low-latency applications .

Advantages

• High Bandwidth Density: 2.5× higher throughput than QSFP+ in the same footprint .
• Backward Compatibility: QSFP28 ports accept QSFP+ modules, easing migration .
• Deployment Flexibility: Supports multiple optical technologies and breakout configurations .
• Monitoring and Management: DDM and CMIS interfaces allow precise network management .

Summary

QSFP28 optical modules are essential for modern high-speed networks, providing 100G connectivity with flexibility, high density, and compatibility across data center and enterprise environments. They serve as a critical component for scaling bandwidth, supporting cloud infrastructure, and enabling long-distance optical links. Their versatility makes them the standard choice for current 100G deployments .