With the continuous surge in data center traffic, the market demand for 100G optical modules is also further increasing. Common 100G optical modules include SR4, LR4, ER4, etc. However, in practical applications, due to the length of the optical fiber link. Several types of optical modules alone cannot meet the most cost-effective optical network transmission solutions in data centers.

Therefore, in the medium and long distance, the CWDM4 MSA organization and the 100G CLR4 alliance have also respectively formulated the 100G QSFP28 CWDM4 standard and the 100G QSFP28 CLR4 standard with a transmission distance of 2 km. So what are the similarities and differences between 100G QSFP28 CLR4 and CWDM4 optical modules with the same transmission distance of 2KM? The following ETU-Link will reveal the answer for you.

Similarities:

1. Both interface types are duplex LC;

2. Both adopt CWDM wavelength division multiplexing technology, and the working wavelengths are 1270, 1290, 1310, 1330nm;

3. Both are single-mode optical modules, and the transmission distance is 2KM.

Differences:

1. 100G QSFP28 CWDM4 optical modules must be used for fiber optic links with Forward Error Correction (FEC).

2. The 100G QSFP28 CLR4 optical module can be used for both optical fiber links with forward error correction (FEC) function and optical fiber links without forward error correction (FEC) function.

3. In the fiber link without forward error correction (FEC) function, the 100G QSFP28 CLR4 optical module can also maintain the performance of low latency and low power consumption. This feature of 100G QSFP28 CLR4 optical module makes it more popular in high-performance computing, high-frequency trading and other fields.

ETU-Link’s 100G QSFP28 CWDM4 optical modules and 100G QSFP28 CLR4 optical modules are cost-effective solutions for 2km transmission applications in data centers. Among them, the application of 100G QSFP28 CWDM4 optical modules in data centers is more common.