The 25G SFP28 transceiver is an optical module designed for 25 Gigabit Ethernet (25GbE) applications. It typically uses the SFP28 (Small Form-factor Pluggable) package, which is similar in size to the SFP+ transceiver but operates at a higher data rate. These transceivers support a variety of wavelengths, including 850nm, 1310nm, and 1550nm, depending on the application and transmission distance requirements.
25G SFP28 transceivers are widely used in data centers and enterprise networks due to their high performance, reliability, and compatibility with existing network infrastructure. They are designed to meet the growing demand for higher bandwidth and faster data transmission rates in modern networking environments.
The most commonly used types of 25G SFP28 transceivers
According to the transmission distance, 25G SFP28 optical modules can be divided into SFP28 SR/LR/ER. These three types of optical modules are mainly used for the interconnection of data center servers, switches and routers, etc.
1) 25G SFP28 SR
The SFP28 SR transceiver is a single-channel, pluggable fiber SFP28 transceiver for 25 Gigabit Ethernet and Infiniband EDR. It is a high-performance short-range data communications module that transmits 70 meters over OM3 multimode fiber and 10 meters over OM4 multimode fiber. The module is designed to use a multimode fiber system with a wavelength of 850nm and an electrical interface using 20 pieces of contact edge type connectors.
The SFP28 SR transceiver complies with multiple standards and specifications such as IEEE 802.3, SFF-8472, SFF-8402, SFF-8432 and SFF-8431 with a center wavelength of 850nm. Because the transmitter inside the SFP 25G SR is a vertical-cavity surface-emitting laser (VCSEL), it needs to be used with OM3/OM4 multimode fiber with a fiber diameter of 50/125µm, which is a short-range transmission optical module. In addition, SFP28 SR has digital optical monitoring (DOM) function, which can help network management to monitor all aspects of optical module information in real-time, and is mainly used in 25G Ethernet switches, routers, networks interface cards and storage network equipment.
2) 25G SFP28 LR
The SFP28 LR transceiver is a single-channel, pluggable fiber SFP28 transceiver for 25 Gigabit Ethernet and Infiniband EDR. Moreover, the 25G SFP28 LR module supports communication and interconnection applications with a transmission distance of up to 10km. The optical interface of SFP28 LR adopts the duplex LC optical interface. The 25G SFP28 LR complies with multiple standards and specifications such as IEEE 802.3, SFF-8472, SFF-8402, SFF-8432 and SFF-8431. Its central wavelength is 1310nm. It is usually used with single-mode optical fiber, and the transmission distance can reach 10km. It is suitable for long-distance data transmission. Moreover, the SFP 25G LR optical module adopts a DFB laser.
3) 25G SFP28 ER
The 25G SFP28 ER optical transceiver with a center wavelength of 1310nm, duplex LC interface, single-mode, supports commercial-grade operating temperature range (0°C~70°C). It’s generally used with single-mode patch cable OS2. It is widely used in the data center 25G Ethernet and 5G forward CPRI/eCPRI networks with the longest transmission distance up to 40KM.
| SFP28 | SR4 | LR4 | ER | ER-Lite(ER30) | BIDI |
|---|---|---|---|---|---|
| Standard | MSA | MSA | MSA | MSA | IEEE 802.3 |
| Connector | Duplex LC | Duplex LC | Duplex LC | Duplex LC | LC simplex |
| Optical Fiber Type | Multi-mode | Single-mode | Single-mode | Single-mode | Single-mode |
| Wavelength | 850nm | 1310nm | 1310nm | 1310nm | 1270nm/1330nm |
| Transmission Distance | 70/100m | 10km | 40km | 30km | 1 0km |
| Laser Type | VCSEL | DML | EML | DML | DFB BiDi |
Other types of 25G SFP28 transceivers
1) 25G CPRI SFP28 ER Lite
The 25G SFP28 ER Lite (ER30) transceiver with a center wavelength of 1310nm, duplex LC interface, single-mode, supports commercial-grade operating temperature range (0°C~70°C). The SFP28 ER30 optical module can transmit up to 30km (without FEC on) or 40km (with FEC on) through single-mode fiber.
2) 25G BIDI
SFP28 BIDI transceiver with a center wavelength of 1270nm-Tx, 1330nm-Rx, simplex LC interface, single-mode, supports industrial-grade operating temperature range (-45°C to 85°C). Generally used with single-mode patch cable OS2. It is widely used in the data center 25G Ethernet and 5G fronthual CPRI/eCPRI networks, with the longest transmission distance up to 40KM.
3) 25G SFP28 CWDM
SFP28 CWDM transceiver with the wavelengths of 1470nm-1570nm (interval 20nm), duplex LC interface, single-mode, supports industrial-grade operating temperature range (-20°C~85°C). It is generally used with single-mode patch cable OS2. It is widely used in the data center 25G Ethernet and 5G fronthual CPRI/eCPRI networks with the longest transmission distance up to 10KM.
4) 25G SFP28 DWDM
SFP28 DWDM transceiver fixed wavelength is C18-C61 (interval 100GHz), duplex LC interface, single-mode, supports industrial-grade operating temperature range (-20°C to 85°C). It is generally used with single-mode patch cable OS2. It is widely used in the data center 25G Ethernet and 5G fronthual CPRI/eCPRI networks, with the longest transmission distance reaching 10KM.
FAQs of 25G SFP28 transceivers
Q、 What is the SFP28 transceiver?
A、After the above introduction, you should have the answer to “what is SFP28”. Generally speaking, the 25G SFP28 belongs to the low-speed optical module type in the optical module market. The SFP28 transceivers make up for the defect that the price of the 40G and 100G optical modules is too high and the rate of 10G optical modules can not meet the needs of users.
Q、What is the maximum supported distance for 25G Transceivers and Cables?
A、The maximum currently supported distance for 25G is 10km with SFP-25G-LR and SFP-25G-MR-LR. Additional optics may be released in the future to support longer distances.
Q、What is the difference between SFP28 and 25G SFP?
A、They are the same. The “SFP” form factor was originally defined for speeds lower than 10G. When it was adopted for 10G, the name became SFP+ to denote the higher aggregate performance. The same SFP form factor was later adopted for 25G with the electrical interface operating at 25Gbps. The electrical interface is designed to accommodate up to 28Gbps, hence the engineering and industry name is SFP28. Walsun refers to the 25G form factor as the 25G SFP to avoid any confusion.
Q、Can 10G SFP+ and 1G SFP transceivers be plugged into Walsun 25G SFP ports?
A、Yes, Walsun 25G SFP ports allow the flexibility to run multiple speeds and support a full range of 10G SFP+ optical modules. The 10GBASE-T (copper) transceiver is supported in a limited range of products – refer to Walsun’s transceiver and cable guide for supported platforms. 1G SFP transceivers can also be used in 25G SFP platforms that support 1G. Please refer to product datasheets for more details on rate support for specific products.
Q、Can 25G SFP transceivers and cables support 10/25G dual rate?
A、Walsun offers three dual-rate 10G/25G SFPs for use with multi-mode fiber (MMF) and single-mode fiber (SMF):
• For MMF: 1. The SFP-25G-MR-SR 10/25G Dual Rate Short Reach (or SR) optical transceiver, supporting 25G up to 100m with duplex OM4 MMF, and 10G up to 400m with duplex OMF MMF. When operated at 10G, the SFP-25G-MR-SR will optically interoperate with 10G-SR SFPs.
2. The SFP-25G-MR-XSR 10/25G Dual rate “eXtended Short Reach” (or XSR) optical transceiver, supporting 25G up to 300m with duplex OM4 MMF and 10G up to 400m with duplex OM4 MMF. When operated at 10G, the SFP-25G-MR-XSR will optically interoperate with 10G-SR SFPs, but attenuation may be required to ensure the maximum input power of the 10G-SR is not exceeded.
• For SMF: 3. The SFP-25G-MR-LR 10/25G Dual rate optical transceiver, supporting 10G or 25G over 10km of duplex SMF.
Q、Are Walsun 25G Transceivers interoperable with other 25G transceivers available in the industry?
A、Yes, as long as the non-Walsun 25G transceivers meet the associated industry standard specifications, Walsun 25G transceivers are fully interoperable.
