The range of a 100G QSFP (Quad Small Form-factor Pluggable) module typically varies between 100 meters to 40 kilometers, depending on the type of optics and the type of fiber used in the network.

What are the Advantages of 100G CWDM4 QSFP28 Compared to Other 100G Optical Transceivers?

100G QSFP28 CWDM4 optical transceivers, in data center applications, have more price advantages than 100G QSFP28 PSM4 optical transceivers in medium and long-distance transmission; compared with 100G QSFP28 LR4 optical transceivers, with a wider application field, so the demand will also be larger; the price advantage is outstanding compared to 100G QSFP28 LR4 optical transceivers.

With the continuous growth of data traffic, the trend of large-scale and flat data centers promotes the development of optical transceivers in two aspects: the upgrade of transmission rate requirements and the increase in quantity requirements. For a large number of optical transceivers used in data centers, low cost and transmission distance are undoubtedly the focus of consideration. Therefore, CWDM4 has become the mainstream of 100G cloud computing data centers.

Overview of 100G QSFP28 LR4 Optical Transceiver

A long time ago, the optical transceiver industry chain was very chaotic. Each manufacturer had its own package structure with various interfaces and different sizes. In order to solve this problem, the multi-source agreement (MSA) came into being. All manufacturers follow the standard proposed by MSA to unify the package structure and related interfaces of optical transceivers, which is similar to the standardization of mobile phone charging ports. For 100G, the standards defined by MSA include 100G PSM4 MSA, 100G CWDM4 MSA, and 100G Lambda MSA.

In addition to the 100GBASE series standards proposed in IEEE, why did MSA also propose PSM4 and CWDM4 standards? 100GBASE-SR4 and 100GBASE-LR4 are the most commonly used 100G interface specifications defined by IEEE. However, for large-scale data center interconnection scenarios, the distance supported by 100GBASE-SR4 is too short to meet all interconnection requirements, and the cost of 100GBASE-LR4 is too high. Therefore, MSA brings to the market mid-distance interconnect solutions, and PSM4 and CWDM4 are the products of this revolution. Of course, the capability of 100GBASE-LR4 completely covers that of CWDM4, but in the scenario of 2 km transmissions, the CWDM4 solution has a lower cost and is more competitive.

100G QSFP28 LR4 and 100G QSFP28 CWDM4 are similar in principle. They both use optical devices MUX and DEMUX to wavelength-division multiplex 4 parallel 25G channels to a 100G fiber link. However, there are a few differences between the two.

In the name of 100G QSFP28 LR4, LR means long reach, that is, 10Km; 4 means four channels, that is, 4*25G, which are combined together to form a 100G optical transceiver that can transmit 10Km.