SFP+ (Small Form-Factor Pluggable Plus) and SFP28 (Small Form-Factor Pluggable 28) are both types of transceiver modules used in networking equipment to support high-speed data transmission. While they share some similarities, they differ primarily in terms of data rates and design. Here are the key differences between SFP+ and SFP28:

1. Data Rate:

• SFP+: Designed to support data rates up to 10 gigabits per second (Gbps) per channel. Common applications include 10 Gigabit Ethernet (10GbE) and 8G/10G Fibre Channel.

• SFP28: Designed to support data rates up to 25 Gbps per channel. It is an evolution of SFP+ to accommodate higher-speed networks, often used in 25 Gigabit Ethernet (25GbE) and 32G Fibre Channel.

2. Number of Channels:

• Both SFP+ and SFP28 modules typically use multiple lanes (channels) for data transmission. The number of lanes may vary based on the specific application and standard.

3. Form Factor:

• The physical form factor of SFP+ and SFP28 is very similar, making SFP28 backward compatible with SFP+ slots. However, SFP28 modules are designed to handle higher data rates.

4. Connector Type:

• Both SFP+ and SFP28 modules use the same LC duplex connector for fiber optic connections.

5. Copper and Fiber Options:

• Both SFP+ and SFP28 modules are available in versions that support both copper (direct attach cables) and fiber optic connections.

6. Distance:

• SFP28 modules may have slightly reduced reach compared to SFP+ modules due to the higher data rates. However, the reach depends on the specific standard and implementation.

7. Application:

• SFP+: Widely used in 10GbE and 8G/10G Fibre Channel applications.

• SFP28: Commonly used in 25GbE and 32G Fibre Channel applications.

8. Backward Compatibility:

• SFP28 modules are often backward compatible with SFP+ slots, allowing SFP28 modules to be used in SFP+ ports. However, the data rate will be limited to the capabilities of the SFP+ slot.

When upgrading or selecting transceiver modules for a network, it's important to consider the specific data rate requirements of the application and the compatibility with existing infrastructure.