QSFP (Quad Small Form-Factor Pluggable) and CFP2 (C Form-Factor Pluggable) are both types of optical transceiver form factors used in high-speed data communication, particularly in data centers and telecommunications. Here are some key differences between QSFP and CFP2: 

1. Size and Form Factor:

• QSFP: QSFP is a smaller and more compact form factor compared to CFP2. QSFP modules typically have a size of 18mm x 72mm.

• CFP2: CFP2 modules are larger, with a size of approximately 22mm x 102mm. The larger form factor allows for additional electronics and greater power handling capacity.

2. Data Rates:

• QSFP: QSFP modules support various data rates, including 40 Gbps, 100 Gbps, and beyond. QSFP28, for example, supports 100 Gbps.

• CFP2: CFP2 modules also support high data rates, commonly used for 100 Gbps and 200 Gbps applications. CFP2-ACO (Analog Coherent Optics) modules can support coherent optical communication for longer-distance transmission.

3. Applications:

• QSFP: QSFP modules are commonly used in data centers and high-performance computing environments for short to medium reach connections.

• CFP2: CFP2 modules are used in a variety of applications, including long-haul telecommunications, metro networks, and data center interconnects. CFP2-ACO modules are specifically designed for coherent optical communication.

4. Power Consumption:

• QSFP: QSFP modules generally have lower power consumption compared to CFP2 modules.

• CFP2: CFP2 modules may consume more power due to their larger size and the potential for additional electronics.

5. Optical Interfaces:

• QSFP: QSFP modules use LC duplex connectors for optical interfaces.

• CFP2: CFP2 modules may use different types of optical interfaces, including LC duplex or MPO/MTP connectors.

In summary, QSFP is a smaller form factor commonly used for high-speed data connections within data centers, while CFP2 is a larger form factor suitable for various applications, including longer-distance optical communication. The choice between QSFP and CFP2 depends on the specific requirements of the networking environment and the intended use case.