Questions and answers of 100G QSFP28 light module related questions

Q1: How many types are 100G QSFP28 light modules?

A1: At present, the 100G light modules on the market include SR4, ESR4, PSM4, CWDM4, CLR4, LR4, ER4, ZR4

What is the difference between Q2: 100G CWDM4/CLR4 and LR4?

A2: The wavelength of the two is different, and the transmission distance is different. The 100G CWDM4/CLR4 light module adopts CWDM coarse wave score technology. The working wavelength is 1270, 1290, 1310, 1330nm. 1295, 1300, 1304, 1309nm.

Q3: 100G QSFP28 light module is the main application?

A3: 100G QSFP28 optical module is mainly used in the core switch of data centers, core router 100G QSFP28 interconnection.

Q4: Can 100g light modules be connected with 25G light modules?

A4: Yes, but only the 100G light module (SR4, ESR4, PSM4) can be connected to the 25G light module, but we need to use the MPO-LC branch jumper to connect the 100G light module to the 25G light module Essence The multi -mode 100G SR4/ESR4 light module can be connected to the multi -mode 25G SR light module, and the single -mode 100G PSM4 can be connected to 25G LR.

Q5: What is the effect of opening and not opening the FEC function on the 100G light module?

A5: The FEC function is used in a 100G high -speed light module. Usually, after opening this function, it will enhance the receiving sensitivity of the optical module, and the transmission distance of the high -speed light module will be longer than that of the FEC function. Although the FEC function has two advantages of forward error correction and increased transmission distance, it is inevitable that some data packets will be delayed in the process of correcting the error code. Therefore, not all high -speed light modules are recommended to turn on this function.

For example, when using the 100G QSFP28 LR4 light module, the FEC function is not recommended. The 100G optical module mainly relies on the FEC function on the device side to implement error correction. Therefore, the switch is also required to support the FEC function. Generally, switches that support the FEC function are opened by default. In addition, it should be noted that if the A -side optical module opens the FEC function, the B -end optical module must also turn on this function, otherwise the interface will not be up.