100G QSFP28 CWDM4 Optical Transceiver Module - Reliable 2km CWDM4

Our review of the 100G QSFP28 CWDM4 Optical Transceiver Module finds it best suited to network engineers and data center teams who need a compact, hot-pluggable 100G link for short single-mode runs. The single biggest reason to buy is the combination of standards compliance and built-in monitoring: this module supports 100GBASE-CWDM4 with ITU-T alignment and offers real-time digital optical monitoring (DOM) so technicians can verify link health without extra test gear. It is a pragmatic choice where 2km single-mode reach, LC connectivity and 100G-to-4x25G breakout are required.

Key Features

• 100GBASE-CWDM4 support: Provides standardized 100G transport across four CWDM wavelengths for predictable interoperability with compliant switches.
• 2 km single-mode reach: Covers common campus and data center interconnect spans without the cost of long-range optics.
• Hot-pluggable QSFP28 form factor: Lets engineers swap or upgrade modules without powering down equipment, minimizing downtime.
• Built-in DOM: Real-time digital optical monitoring enables live diagnostics of transmit power, receive power and temperature to simplify troubleshooting.
• 100G to 4x25G breakout: Supports breakout applications when converting a 100G port into four 25G lanes for flexible deployment.
• Low power and commercial temp: 3.5W power consumption and 0 to 70C operating range for typical indoor networking environments.

Who It's For

This module is aimed at IT professionals operating modern top-of-rack and aggregation switches that support QSFP28 MSA optics and require 100G single-mode connectivity over short campus or data center links. It is particularly useful where breakout to 4x25G is needed for server connectivity or for staged upgrades from 25G to 100G.

Those who should look elsewhere include sites that need extended temperature ranges, multimode fiber links, or distances beyond 2 km; in those cases consider long-reach or multimode-specific transceivers designed for those environments.

Pros & Cons

Pros

• Standards compliant with IEEE and ITU-T guidance for reliable interoperability.
• Hot-pluggable QSFP28 package and support for 100G to 4x25G breakout increase deployment flexibility.
• Built-in DOM gives practical, on-demand diagnostic data to reduce troubleshooting time.
• Low power draw (about 3.5W) helps limit cooling and power impacts in dense racks.

Cons

• Limited to 2 km single-mode reach, so not suitable for longer metropolitan or long-haul links.
• Commercial temperature range only, which may be restrictive for outdoor or harsh environments.

Specifications

Our Verdict

For data center and campus networks that need an affordable, standards-based 100G single-mode module with diagnostic visibility, this QSFP28 CWDM4 is a practical choice. Its hot-pluggable design, DOM and breakout support deliver flexibility and maintainability, making it good value for installations within the 2 km reach and normal indoor temperature ranges.

Frequently Asked Questions

Can this module break out to four 25G ports?
Yes. It supports 100G to 4x25G breakout applications when used with compatible switch hardware.

Does it include real-time monitoring for diagnostics?
Yes. The module has built-in DOM functionality for transmit/receive power and other status metrics.

What fiber and connector type does it use?
It uses single-mode fiber with duplex LC connectors and operates across four CWDM wavelengths.