The QSFP28 100G transceiver has a distance of 100 meters over multi-mode fiber and 10 kilometers over single-mode fiber.

QSFP28 100G Transceiver Application Guide

Nowadays, 100G optical QSFP28 transceivers account for a significant portion of networking construction. Due to their compact size, low power consumption, and high performance, 100G QSFP28 optics are mainly used for the following situations.

• 100G Ethernet

• Data Center Interconnect

• Infiniband QDR and DDR Interconnect

• Enterprise networking

However, due to the different properties and functions of various types, their exact application is based on the actual needs in a real environment. QSFP28 100G SR4 is mainly applicable in a 100G data center with a demand for short transmission distances between 5m and 100m.

QSFP28 100G PSM4 and QSFP28 100G CWDM4 are specially designed for network applications with a transmission distance of 500m and 2km. While QSFP28 100G CWDM4 is relatively more costly, it requires only two single-mode fibers for transceiving and transmitting in both directions, which is much less than the eight single-mode fibers of PSM4, making it a high-quality choice for Enterprise networking and 100G Ethernet.

QSFP28 100G LR4, generally used together with LC single-mode fiber cables, can reach a maximum transmission distance of 10km. It converts 4X25Gbps electrical signals into 4 LAN WDM optical signals and then multiplexes them into a single channel to realize 100G optical transmission.

QSFP28 100G ER4 supports the 100G data connection by using WDM multiplexing wavelength division technology. It can reach a maximum transmission distance of up to 40KM, making it a perfect choice for optical communication and applications compliant with Ethernet 100GBASE-ER4 Lite standard.

How to Select the Best 100G QSFP28 Optics?

Now that we know we have to choose the best 100G optics based on our actual demand, but how? How can we choose the right one? Here is a selection guide for you.

For transmission distances between 5m and 100m, you can choose the QSFP28 SR4 optical transceiver module. It can transmit 70m using OM3 fibers or 100m using OM4 fibers.

For transmission distances between 100m to 2km, QSFP 100G PSM4 or QSFP28 CWDM4 modules would be better. The cost of QSFP28 CWDM4 is much higher than the QSFP28 PSM4. However, the QSFP28 CWDM4 requires only two single mode fibers in two-way transmission which is much less than the eight single mode fibers of QSFP28 PSM4, and the total cost of the QSFP 100G PSM4 rises very quickly. In practical applications, it is necessary to decide whether to use QSFP28 PSM4 or QSFP28 CWDM4 depending on the interconnection distance.

For transmission distance between 10km to 40km, you can consider QSFP 100G LR4 which has a maximum transmission distance of up to 10 km, or QSFP28 ER4 transceivers which can reach up to a maximum transmission distance of even further—40km.