40GBASE-LR4 QSFP+ 1310nm 10km Optical Transceiver - LR4

In this review the OPSTRAN 40GBASE-LR4 QSFP+ module is evaluated for network engineers and IT teams who need a dependable single-mode 40G link up to 10km. The bottom line: this QSFP+ transceiver delivers standards-compliant 40GBASE-LR4 performance with built-in digital optical monitoring and a modest 3.5W power draw, making it a practical choice where long-reach fiber, hot-pluggable convenience and device compatibility matter most.

Key Features

• 40GBASE-LR4 support: Provides a tested 40 Gbps single-mode connection designed for up to 10km over duplex LC fiber, suitable for long-reach links.
• 4 CWDM lanes: The MUX/DEMUX design splits signals into four CWDM channels enabling up to 11.2Gbps per channel for stable aggregated throughput.
• Real Time Digital Optical Monitoring: Integrated DDM lets administrators monitor optical power and diagnostics in real time for faster fault isolation.
• Low power operation: With a maximum power consumption of 3.5W the module minimizes heat output and eases thermal budget concerns in dense switch deployments.
• Standards and form factor compliant: Hot pluggable QSFP+ form factor compliant to SFF-8436, QSFP MSA and IEEE 802.3ba ensures broad interoperability when EEPROM coding matches target switches.
• Commercial temperature rating: Rated for 0 to 70C (32 to 158F) for reliable operation in typical data center and network closet environments.

Who It's For

The module is aimed at network administrators, enterprise IT teams, and service providers who need a cost-effective 40G single-mode interface for aggregation, spine links, or long-reach server connectivity. Its built-in DDM and standards compliance make it a solid choice where operational visibility and predictability are important.

It is less suited for extreme temperature environments outside the commercial range or for networks requiring multimode optics; organizations with very specific vendor-locked EEPROM requirements should confirm compatibility via the supplier's compatibility lab before deploying at scale.

Pros & Cons

Pros

• Standards-compliant QSFP+ design and IEEE 802.3ba electrical interface support broad switch compatibility when properly coded.
• Built-in DDM provides useful diagnostic data to speed troubleshooting and reduce downtime.
• Low maximum power consumption of 3.5W reduces heat and power requirements in dense racks.
• Tested in targeted switch devices with vendor compatibility checks increases reliability in mixed environments.

Cons

• Commercial temperature range (0 to 70C) may be limiting for outdoor or non-climate-controlled sites.
• Successful operation depends on correct EEPROM coding for some switch vendors, which can require verification.

Specifications

Form Factor	QSFP+
Standard	40GBASE-LR4, IEEE 802.3ba
Wavelength	1310nm (4 CWDM lanes)
Max Reach	10km over single-mode fiber (duplex LC)
Power Consumption	Max 3.5W
Temperature Range	Commercial 0 to 70C (32 to 158F)
Monitoring	Real Time Digital Optical Monitoring (DDM)

Our Verdict

The OPSTRAN 40GBASE-LR4 QSFP+ is a practical, standards-compliant transceiver for teams that need reliable 40G single-mode links up to 10km. With DDM, low power draw and vendor compatibility testing it offers good operational value for data center and enterprise backbone use, provided the deployment stays within commercial temperature limits and EEPROM compatibility is confirmed.

Frequently Asked Questions

Is this module hot pluggable?
Yes. The QSFP+ form factor is hot pluggable so it can be inserted or removed without powering down the host device.

What fiber connector does it use?
It uses duplex LC connectors for single-mode fiber links.

Does it include monitoring features?
Yes. The transceiver includes built-in real time digital optical monitoring for diagnostics and optical power reporting.