Comprehensive Guide to QSFP-DD, QSFP28, QSFP56, SFP56, and SFP28 Optical Transceivers

Comprehensive Guide to QSFP-DD, QSFP28, QSFP56, SFP56, and SFP28 Optical Transceivers

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 Complete Guide to QSFP-DD, QSFP28, QSFP56, SFP56, and SFP28 Optical Modules

As high-speed networks continue to evolve, optical transceivers like QSFP-DD, QSFP28, QSFP56, SFP56, and SFP28 have become the core components enabling scalable and efficient connectivity across data centers and telecom environments. Below is a detailed breakdown of each module series.

QSFP-DD – Quad Small Form-factor Pluggable Double Density

  • Form Factor: QSFP-DD (8x lanes)

  • Data Rate: Up to 800Gbps (8x100G)

  • Connector: MPO-16, Dual LC, or Dual CS

  • Distance: Up to 10km+ (depending on module)

  • Mode: Single-mode (SMF), Multi-mode (MMF)

  • Application: AI data center, spine-leaf interconnect, hyperscale backbone, 5G backhaul

QSFP-DD is designed to support next-generation 400G/800G Ethernet. Its double-density design allows more bandwidth within the same footprint.

 QSFP28 – Quad Small Form-factor Pluggable 28Gbps

  • Form Factor: QSFP28 (4x lanes)

  • Data Rate: Up to 100Gbps (4x25G)

  • Connector: MPO-12 or Duplex LC

  • Distance: 100m (MMF) to 40km (SMF)

  • Mode: Single-mode & Multi-mode

  • Application: 100G Ethernet, CWDM4, LR4, SR4 links in enterprise and cloud data centers

QSFP28 is widely deployed in 100G infrastructures with excellent compatibility and cost-efficiency.

QSFP56 – Quad Small Form-factor Pluggable 56Gbps

  • Form Factor: QSFP56 (4x lanes)

  • Data Rate: Up to 200Gbps (4x50G PAM4)

  • Connector: MPO-12 or LC

  • Distance: 100m to 10km

  • Mode: Single-mode & Multi-mode

  • Application: 200G Ethernet, InfiniBand HDR, HPC, AI/ML workloads

QSFP56 is the ideal solution for high-throughput environments where 200G interconnect is needed.

 SFP56 – Small Form-factor Pluggable 56Gbps

  • Form Factor: SFP (1x lane)

  • Data Rate: Up to 50Gbps (1x50G PAM4)

  • Connector: LC

  • Distance: 100m (SR) to 10km (LR)

  • Mode: Single-mode & Multi-mode

  • Application: 5G fronthaul, leaf switch uplinks, edge devices

SFP56 modules are compact yet powerful solutions for high-speed 50G Ethernet and telecom networks.

SFP28 – Small Form-factor Pluggable 28Gbps

  • Form Factor: SFP (1x lane)

  • Data Rate: Up to 25Gbps (1x25G NRZ)

  • Connector: LC

  • Distance: 100m (SR) to 10km (LR)

  • Mode: Single-mode & Multi-mode

  • Application: 25G Ethernet, cloud access, TOR switch uplinks

SFP28 modules offer cost-effective, reliable performance in both legacy and modern networking setups.

Choosing the Right Transceiver

Module Max Speed Connector Typical Distance Best For
QSFP-DD 800Gbps MPO-16/LC/CS Up to 10km+ Hyperscale, AI
QSFP56 200Gbps MPO-12/LC Up to 10km HPC, AI
QSFP28 100Gbps MPO-12/LC Up to 40km Cloud, Enterprise
SFP56 50Gbps LC Up to 10km 5G, Edge
SFP28 25Gbps LC Up to 10km TOR, Access

Conclusion

Whether you're scaling up a data center or deploying edge connectivity for telecom, selecting the right optical transceiver is crucial. Understanding the specifications of QSFP-DD, QSFP28, QSFP56, SFP56, and SFP28 helps you build high-performance, future-ready networks.

For reliable and cost-effective transceivers, always partner with a trusted manufacturer or distributor that guarantees 100% compatibility and rigorous testing.

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