100GBASE-LR4 QSFP28 Module 100G 10km LC - Low Power, DDM

In this review of the 100GBASE-LR4 QSFP28 module from QSFPTEK, the bottom line is simple: this is a practical, no-nonsense 100 Gigabit optical transceiver for network engineers who need reliable long-reach links up to 10km. The reviewer found the module to be straightforward to deploy in lab and production environments, offering 100G data rate, duplex LC connectivity and built-in DDM for live diagnostics, all while keeping power consumption low. It is aimed at users wanting a Cisco-compatible LR4 option without vendor lock-in.

Key Features

• 100G link: Provides full 100 Gigabit performance suitable for backbone and data center uplinks.
• 10km reach: Duplex LC connectors and LR4 optics support single-mode fiber links up to 10km for campus or inter-building runs.
• Built-in DDM: Digital diagnostics monitoring gives real-time access to optical parameters for easier troubleshooting.
• Low power: The module consumes around 3.5W, which helps reduce overall system power and cooling needs.
• Hot pluggable and FEC support: Hot-swappable QSFP28 design with Host FEC compatibility simplifies upgrades and improves link stability.
• Vendor compatibility: Compatible with Cisco 100Gigabit ethernet coding and 200+ vendors, easing integration into heterogeneous networks.

Who It's For

This module is aimed at network administrators and system integrators running 100G infrastructure in data centers, enterprise core layers, or campus backbones who need a reliable LR4 module with monitoring. It is particularly useful where duplex LC single-mode fiber already exists and where a cost-effective alternative to a first-party transceiver is acceptable.

Those who should look elsewhere include users requiring multimode fiber support, links beyond 10km, or proprietary vendor-specific modules mandated by strict compatibility policies at some service providers. For short-reach or copper-based links, a different QSFP option would be more appropriate.

Pros & Cons

Pros

• Provides true 100GBASE-LR4 performance suitable for telecom and data center uplinks.
• Supports DDM for live diagnostics, which simplifies monitoring and troubleshooting.
• Low power draw around 3.5W reduces thermal load in dense systems.
• Wide vendor compatibility and Cisco coding make integration straightforward in mixed environments.

Cons

• Limited to single-mode fiber and 10km reach, so it is not suitable for longer-haul applications.
• Not designed for multimode fiber installations, which require different optics.

Specifications

Form factor	QSFP28
Data rate	100G
Wavelength / Type	1310nm LR4
Maximum link length	10km over single-mode fiber
Connector	Duplex LC
Power consumption	Approximately 3.5W
Diagnostics	DDM / DOM supported

Our Verdict

The QSFPTEK 100GBASE-LR4 QSFP28 module is a solid value for engineers needing a 100G LR4 transceiver with monitoring and low power use. It fits standard QSFP28 slots, supports Host FEC and DDM, and is a practical Cisco-compatible option for data centers and campus backbones where 10km single-mode links are required.

Frequently Asked Questions

Is this module compatible with Cisco devices?
Yes, it is coded for compatibility with Cisco QSFP-100G-LR4-S and is reported to be compatible with 200+ vendors, though checking device firmware is recommended.

Does it support diagnostics and monitoring?
Yes, the module supports DDM/DOM for real-time monitoring of optical parameters.

What fiber and connectors are required?
Use single-mode fiber with duplex LC connectors; the LR4 optics are rated for up to 10km links.