The main packaging types for 100G optical modules are CFP, CFP2, CFP4, and QSFP28, with QSFP28 being the current mainstream standard in data centers.

Overview of 100G Module Packaging

100G optical modules are high-speed transceivers that convert electrical signals into optical signals for data transmission at 100 Gbps. Their packaging type determines size, power consumption, port density, and application suitability .

CFP Series (CFP, CFP2, CFP4)

• CFP: The original 100G form factor, large in size (144.75 mm × 82 mm × 13.6 mm), high power consumption (10–24W), suitable for long-distance transmission like 100GBASE-LR4 and ER4 . Requires a built-in gearbox for signal conversion.
• CFP2: Reduced size by ~50% (41.5 mm × 107.8 mm × 12.35 mm), lower power consumption (6–12W), supports 4×25 Gbps or 10×10 Gbps lanes, suitable for medium- to long-distance links .
• CFP4: Further miniaturized, more energy-efficient, supports 4×25 Gbps lanes, designed for higher port density while maintaining long-distance capabilities .

QSFP28 (Quad Small Form-Factor Pluggable 28)

• Size: Compact (18.3 mm × 56.5 mm × 8.5 mm), about 1/5 the size of CFP, enabling high port density in 1U racks .
• Architecture: Quad-channel design with 4 independent 25 Gbps channels aggregated to 100 Gbps .
• Power Consumption: Low, typically ≤3.5W, with some low-power models at 2.5W .
• Applications: Ideal for short- to medium-distance data center interconnections, cloud computing, and high-performance computing networks .
• Advantages: Hot-swappable, IEEE-compliant, supports high-density deployment, and integrates I2C management for monitoring module status .

Evolution and Current Trends

• CFP modules were the first widely adopted 100G packaging but are gradually replaced due to large size and high power consumption .
• CFP2 and CFP4 improved port density and energy efficiency, but QSFP28 has become the mainstream choice in modern data centers due to its compact size, low power, and high-density deployment capability .

Summary

For 100G optical modules:

• CFP: Large, high-power, long-distance applications.
• CFP2/CFP4: Smaller, more efficient, medium- to long-distance.
• QSFP28: Compact, low-power, high-density, mainstream for data centers. Choosing the right packaging depends on distance requirements, port density, power constraints, and network architecture .