A practical guide to selecting and implementing 25G optical modules, based on network needs and equipment compatibility.
1. Overview of 25G optical modules
25G optical module is an optical fiber communication module with a transmission rate of 25Gbps, which is widely used in high-bandwidth scenarios such as data centers and 5G bearer networks, and has the characteristics of low power consumption, high speed, short-distance and long-distance transmission, and helps the deployment of high-speed data communication networks
2. Features of 25G Optical Modules
2.1. SFP28（Small Form-Factor Pluggable 28）
Features：
- SFP28 is an upgraded version of the SFP (Small Form-factor Pluggable) series of optical modules,which supports 25G transmission rates.
- sfp28has the same interface size, which is compatible with 10G SFP+ modules. It is able to be a direct replacement for 10G modules, but offering higher bandwidth.
- It is suitable for a wide range of Ethernet and Fibre Channel applications in data centre switches, routers and other equipment.
- It offers a variety of transmission distance options, such as short range (SR), medium range (LR), and long range (ER).
- Common applications: 25G Ethernet switches, router connectivity, Fibre Channel, data centre interconnect, etc.
2.1.1. SFP28 LR（Long Range）
- Supportinglong distance transmission, typically 10 km or more (based on single mode fibre).
- Beingsuitable for network applications that require a large range of connectivity.
- Applications:data centers, wide area networks (WAN), long distance communications, etc.
2.1.2. SFP28 SR（Short Range）
- Advisable forshort distances, typically a few hundred meters to a few kilometers (based on multimode fibre).
- Compatible withinternal data centre networks, connections between switches and servers.
- Application environment:data centers, local area networks (LAN), etc.
2.1.3. SFP28 ER（Extended Range）
- Provides longer transmission distances, typically 40 km or more (based on single-mode fibre).
- Fittingfor enterprise applications that require longer transmission distances.
- Operational context：long distance Metropolitan Area Networks (MAN), enterprise level network connectivity, etc.
2.2. QSFP28（Quad Small Form-Factor Pluggable 28）
Features：
- QSFP28 supports transmission of up to 100Gbps (4×25G) per module for applications requiring high bandwidth.
- Idealfor 100G Ethernet, InfiniBand, data centre internal networks, etc.
- Being able to connect different devices over multiple fibre channels
- Supported transmission media include optical fibre and copper.
- Common applications: high bandwidth network applications, data centre switches, servers, high performance computing (HPC), etc.
3. Future Trends in 25G Optical Modules
The future trend of 25G modules is mainly reflected in the following aspects: first, with the increased demand for high-speed and low-latency communications in data centres, 25G optical modules will be widely used in data centre interconnection and cloud computing. Second, with the promotion of 5G networks, the application of 25G optical modules in base station backhaul and access networks will also continue to grow. In addition, miniaturisation, high integration and low power consumption technologies for 25G modules will become the focus of R&D, driving further improvements in module performance. Finally, with the maturity of the technology, the cost of 25G optical modules will gradually decline, promoting its widespread popularity.
4. Conclusion
When choosing different types of 25G optical modules, it is necessary to make a comprehensive consideration based on factors such as transmission distance, application scenarios and equipment compatibility.
