The Quad Small Form-Factor Pluggable 28 (QSFP28) is a compact and high-density optical transceiver module used in data communication applications. It is designed for high-speed data transmission over optical fiber, particularly in data center and networking environments. Here are some key specifications of QSFP28: 

1. Form Factor:

• QSFP28 has a compact form factor, with four channels capable of transmitting or receiving data independently.

• The module is hot-pluggable, meaning it can be inserted or removed without shutting down the system.

2. Data Rate:

• QSFP28 supports data rates of up to 100 Gbps per channel. Therefore, it provides a total aggregated data rate of 400 Gbps (4 channels).

3. Connector Type:

• QSFP28 modules typically use MPO (Multi-Fiber Push-On) connectors for optical connections.

4. Transmission Media:

• QSFP28 modules support optical fiber as the transmission medium. The specific type of optical fiber (single-mode or multimode) and the maximum reach depend on the module's design and the type of optics used.

5. Wavelength:

• The specific wavelength or range of wavelengths supported by QSFP28 modules depends on the intended application (e.g., LR4 for Long Range, SR4 for Short Range).

6. Reach:

• The reach of QSFP28 modules varies based on the optics and the type of fiber used. Different modules are available for short-range, medium-range, and long-range applications.

7. Power Consumption:

• Power consumption is an important consideration for data center equipment. QSFP28 modules are designed to be power-efficient, and the power consumption can vary based on the specific module and its functionality.

8. Temperature Range:

• QSFP28 modules are designed to operate within specific temperature ranges to ensure optimal performance.

9. Compatibility:

• QSFP28 modules are designed to be compatible with QSFP28 ports on networking equipment, switches, and routers.

10. Applications:

• QSFP28 is commonly used in high-speed networking applications, including 100G Ethernet, InfiniBand EDR, and other high-performance computing environments.

It's important to note that the specifications can vary between different QSFP28 modules based on their intended use and the specific manufacturer. When deploying QSFP28 modules, it's crucial to ensure compatibility with the networking equipment and adhere to the recommended guidelines provided by the module manufacturer.