QSFP+ MSA

1. Introduction

The QSFP+ MSA (Quad Small Form-factor Pluggable Plus Multi-Source Agreement) is a widely accepted industry specification for 40Gbps optical transceivers. It ensures that modules from different vendors are mechanically, electrically, and functionally interchangeable, meeting enterprise and data-center expectations for compatibility and reliability.

2. What is QSFP+ MSA?

“MSA” means multiple manufacturers collaborate to define a shared specification—not an official standards body like IEEE, but the MSA ensures practical consistency across vendors’ products. QSFP+ includes four electrical lanes (each 10Gbps) aggregated into a compact, hot-swappable form factor defined under the QSFP MSA.

3. Key Technical Highlights of QSFP+ MSA

  • Form Factor & Pins
    QSFP+ modules use a 38-contact connector, balancing high-speed differential signals, power, and control lines. Proper PCB layout—like microstrip traces and solid grounding—is essential for signal integrity.

  • Digital Diagnostics (DDM / I²C)
    Modules compliant with QSFP+ MSA support I²C-based digital diagnostic monitoring, enabling real-time access to temperature, voltage, and optical performance parameters.

  • IEEE 802.3ba Compatibility
    QSFP+ modules follow IEEE 802.3ba protocols for 40GBASE-SR4, LR4, FR4, and ER4, ensuring broad applicability across multimode and single-mode fiber networks.

4. LINK-PP QSFP+ Products Highlighted

LINK-PP offers a full lineup of QSFP+ modules designed for industry-grade interoperability:

  • LQ-M8540-SR4C – 40GBASE-SR4, 850nm, up to 150m over OM4 (100 m OM3), MPO/MTP interface, breakout to 4×10G, with DDM via I²C.

  • LQ-CW40-LR4C – 40GBASE-LR4, 1310nm, up to 10km over SMF, Duplex LC. Supports IEEE 802.3ba LR4, QSFP+ MSA, ~≤ 3.3 W power, DDM, and standards like OTN/OTU3.

  • LQ-CW40-FR4C – 40GBASE-FR4, 1310nm, up to 2km over SMF, Duplex LC. Aggregates four 10 Gbps electrical lanes into one optical channel and demultiplexes on receipt.

All LINK-PP modules are fully QSFP+ MSA-compliant, ensuring they integrate seamlessly with popular brands like Cisco, Juniper, Arista, HPE, and more.

5. Why QSFP+ MSA Matters for Data Centers & IT Teams

  1. Interoperability – You can mix and match modules and equipment from different vendors without worry.

  2. Scalability – Breakout options (such as SR4 to 4×10G) give design flexibility in evolving network layouts.

  3. Real-time health monitoring – DDM ensures networks stay visible and manageable.

  4. Efficient design – The compact form factor packs 40Gbps density with lower power and thermal footprint.

LINK-PP QSFP+ Module

6. Choosing the Right LINK-PP QSFP+ Module

Use Case

Recommended Module

Highlights

Short-range (rack-to-rack)

LQ-M8540-SR4C

Up to 150m over multimode fiber, MPO interface, breakout ready

Long-distance single-mode

LQ-CW40-LR4C

10km reach, Duplex LC, low power, broad compatibility

Medium-distance

LQ-CW40-FR4C

2km reach, cost-efficient, CWDM aggregation

Up to 40km span

LQ-CW40-ER4C

40km reach for extended deployments

7. Conclusion

The QSFP+ MSA underpins 40Gbps optical networking with trustworthy, multi-vendor interoperability. LINK-PP’s QSFP+ modules—SR4, LR4, FR4, ER4—demonstrate compliance, performance, and reliability. These modules are ideal for modern data center, cloud, or campus network backbones.

Whether optimizing for reach, power, breakout flexibility, or brand compatibility, LINK-PP’s QSFP+ Module ensures a seamless, future-proof solution for high-speed connectivity.