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The Things You Should Know About 100G QSFP28



There are many different 100G QSFP28 optical modules. Do you know the difference between these models? This article will introduce some common 100G QSFP28 optical modules like 100GBASE-SR4 and 100GBASE-LR4 in detail.

In the past few years, 5G networks have been growing rapidly. Many data centers and enterprises are under increasing pressure for bandwidth, and data centers have been trying to increase their transmission bandwidth and density. Many data centers are trying to upgrade their networks, the demand for QSFP28 100G transceivers in data centers has grown significantly. Among several factor forms of 100G optical modules, QSFP28 factor modules are particularly popular because of their small size, low power consumption, and wide range of applications. This article will introduce the features, parameters and application scenarios of each model in QSFP28 modules. Including QSFP28 SR4, QSFP-100G-LR4, 100G QSFP28 PSM4, QSFP-100G-CWDM4-S, QSFP- 100G-ER4L-S.


QSFP28 100G SR4 Transceiver Wiki


The 100GBASE-SR4 is the most common one in the 100G optical module series. The QSFP28 100GBASE-SR4 is a hot-pluggable, full-duplex optical transceiver module designed for short-range transmission in 100G Ethernet networks, operating at 850nm wavelength. 100G QSFP28 modules are smaller than the 100G CFP/CXP modules, and the power consumption of the QSFP28 SR4 is typically less than 1.8W. This feature provides higher transmission density and energy cost savings. The QSFP28 SR4 module provides four independent transmit and receive channels, each transmit channel operating at 25Gbps and up to 70 meters with OM3 multimode fiber and up to 100 meters with OM4 MMF. In addition, the QSFP28-100G-SR4 is fully compliant with IEEE 802.3bm standards, as well as SFP28 MSA, SFF-8665, SFF-8636, RoHS, CPRI, and eCPRI. The 100GBASE-SR4 module is also the cheapest of the 100G QSFP28 transceivers.


Figure 1: 100GBASE-SR4 Optical Modules


When using the MTP harness cable, the 100G SR4 can be connected to four SFP28 25G SR modules. This type of connection is typically used in data centers, campus networks, and enterprise core layers to build high-density networks. Also, direct 100G to 100G connections can be established by using 100G MTP trunk cables. QSFPTEK offers the cost-effective QSFP-100G-SR4-S for $49.90.


Figure 2: 100G QSFP28 SR4 Connection


QSFP28 100GBASE-LR4 Transceiver Wiki


When the transmission distance of your 100G network reaches several kilometers, you need to use the 100G QSFP28 LR4 optical module. This optical module uses a DFB laser, it is designed with duplex LC connectors, and it can theoretically transmit 10km with OS2 optical fiber. This distance can be applied to small data center links between districts and campus networks and other 100 Gigabit Ethernet applications that have certain requirements on transmission distance. On the 100G Transponder board, 100GBASE-LR4 is often deployed as a port on the client side for connecting to devices at the access layer.


Figure 3: 100GBASE-LR4 Optical Module


100G QSFP28 PSM4 Transceiver Wiki


The 100GBASE-PSM4 optical modules design has a similar architecture to the 100G SR4, also with MTP/MPO-12 male connectors, a DFB laser type. The operating wavelength of 100GBASE-PSM4 is 1310 nm. The QSFP28 PSM4 has a maximum transmission distance of 500m via OS2 single-mode fiber. The module can be connected to four SFP28 25G LR modules with MTP-12 breakout cables. The 100G QSFP28 PSM4 is typically used in the data center, enterprise core, and distribution layer applications, the 100GBASE-PSM4 can be connected to four SFP28 25G LR modules over MTP harness cables, just like the 100G QSFP28 SR4.


Figure 4: 100GBASE-PSM4 Optical Module


100G QSFP28 CWDM4 Transceiver Wiki


The 100G QSFP28 CWDM4 is fully compliant with QSFP MSA, CWDM4 MSA, and part of IEEE P802.3bm standard, it is designed with an LC duplex connector, and it is also a hot-swappable, photonic integrated optical module. The 100GBASE-CWDM4 can reach up to 2 km of low-cost 100GB Ethernet in data center applications. 100G QSFP28 CWDM4 modules are much less costly than QSFP 100G LR4 optical modules for optical links over two kilometers. The QSFP28 can use an optical multiplexer for 100Gb/s to 4x25Gb/s CWDM optical signal demultiplexing and 4x25Gb/s to 100G optical signal multiplexing, to achieve 100G CWDM optical signal transmission.


QSFP28 100GBASE-ER4 Transceiver Wiki


When the transmission distance is up to 40km, then we should choose 100GBASE-ER4 optical modules, this module is adapted with DML TOSA, the power budget of QSFP28 100G ER4 transceiver is around 18dB (for BER= 1x10-5). With this power budget, without considering other losses, the maximum transmission distance can reach 40 kilometers by using a G.652 fiber. The 100G QSFP28 ER4 modules can extend the transmission distance by amplifying the optical signal through a Semiconductor Optical Amplifier (SOA). The power consumption of QSFP28 ER4 is less than 4.5W. This module is fully compliant with QSFP MSA, IEEE 802.3ba 100GBASE-ER4 Lite, and OTU4 standards. The QSFP 100G ER4 optical module used in the DCI network of the data center provides a cost-effective choice for long-haul interconnection between data centers with 100G ports.


Figure 5: 100GBASE-ER4 Optical Module


100G QSFP28 ZR4 Transceiver Wiki


In the past, if the interconnection distance between data centers reached 80 km and the capacity reached 100G or more. We usually used 100G DWDM systems or 100G coherent solutions. But now you have a more economical option, and that is the QSFP28 100G ZR4 solution. The 100GBASE-ZR4 optical transceiver is designed to use single-mode fiber (SMF) with a wavelength of 1310nm over a duplex LC connector, the maximum 100Gbps Ethernet transmission distance of up to 80km. It features a separated BOX+FPC+PCBA design with really good reliability, airtightness and heat dissipation. The transceiver is fully compliant with IEEE 802.3ba 100GBASE-LR4 and IEEE 802.3bm CAUI-4 standards. Digital diagnostics functions (DDM) are also available through the QSFP28 MSA's specified I2C interface, allowing access to real-time operating parameters. With these features, the easy-to-install, hot-pluggable QSFP28 100G ZR4 transceiver is suitable for a variety of applications such as 100G Ethernet, telecom, and data centers.

Figure 6: 100GBASE-ZR4 Optical Module




This article introduces six different 100G QSFP28 optical modules including QSFP28 SR4, QSFP-100G-LR4, 100G QSFP28 PSM4, QSFP-100G-CWDM4-S, QSFP- 100G-ER4L-S. With this article, you can learn more about 100G modules, some modules can create 100G to 4x25G connections such as 100G QSFP28 SR4. When you choose different modules to build your fiber optic link, you should first figure out what they are used for, these optical modules have different applications. QSFPTEK can provide all types of 100G QSFP28 modules listed above, as well as complete technical services and after-sales services. Please contact [email protected] to get a quote.




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