100G QSFP28 PAM4 ER1 1310nm 40km

Q1: How many types of 100G QSFP28 optical modules are there?

A1: Currently, the 100G optical modules available on the market include 100G QSFP28 SR4, 100G QSFP28 PSM4, 100G QSFP28 CWDM4, 100G QSFP28 LR4, 100G QSFP28 ER4, and 100G QSFP28 ZR4. The relevant parameters can be seen in the table below.

Q: What happens if the power consumption of the 100G QSFP28 SR4 optical module exceeds 3.5W?

A: All 100G QSFP28 SR4 optical modules from Huaxun Optical Communication cannot exceed 3.5W of power consumption. If the power consumption exceeds 3.5W, the performance of the optical module cannot be guaranteed due to factors such as airflow direction, ambient temperature, and altitude.

Q: Can the QSFP28 SR4 optical module operate with a 100G SR10 optical module?

A: No, the 100G QSFP28 SR4 optical module has only four transmit and receive channels, which is not enough to support the ten 10G transmission channels of the 100G SR10 optical module. The QSFP28 SR4 only supports 4x10G or 4x25G transmission and cannot operate with the 100G SR10 optical module.

Q: Are QSFP28 and QSFP+ optical modules compatible?

A: QSFP28 optical modules cannot be used in QSFP+ ports, and similarly, QSFP28 optical modules cannot operate in QSFP+ ports for 100Gbps data transmission. The principle of mixing different rate optical modules on switches boils down to the fiber and switch port used; the optical module port must match the shape of the switch port, and the switch port rate must be equal to or greater than the optical module rate used. To ensure normal network transmission, ensure that both ends are connected with the same connector and that there are no compatibility issues. QSFP28 ports can use QSFP+ optical modules, but QSFP28 optical modules cannot achieve 100Gbps data transmission on QSFP+ ports.

Q: Is it necessary to clean the connector of the QSFP28 SR4 optical module? If so, how should it be cleaned?

A: Yes, dust and contaminants can accumulate on the connector of the QSFP28 SR4 optical module, potentially reducing the transmit optical power. To ensure transmission stability, Huaxun Optical Communication recommends cleaning the connector every time it is disconnected and reconnected. A one-click MTP/MPO fiber pen cleaner is the best choice for cleaning the QSFP28 SR4 optical module.

Q: What are the differences between 100G CWDM4/CLR4 and LR4 optical modules?

A: The wavelengths and transmission distances are different. The 100G CWDM4/CLR4 optical modules use CWDM coarse wavelength division technology with operating wavelengths of 1270, 1290, 1310, and 1330nm, while the 100G LR4 optical module uses LAN WDM technology with operating wavelengths of 1295, 1300, 1304, and 1309nm.

Q: Where are 100G QSFP28 optical modules mainly used?

A: 100G QSFP28 optical modules are mainly used for interconnection in data center core switches and core routers with 100G QSFP28 ports.

Q: Can 100G optical modules connect with 25G optical modules?

A: Yes, but only MPO interface 100G optical modules (SR4, eSR4, PSM4) can connect with 25G optical modules. An MPO-LC branch patch cord is needed to connect the 100G optical module to the 25G optical module. Multimode 100G SR4/eSR4 optical modules can connect with multimode 25G SR optical modules, and single-mode 100G PSM4 can connect with 25G LR.

Q: What is the impact of enabling or disabling the FEC function on 100G optical modules?

A: The FEC function is used in high-speed optical modules like 100G to enhance the receiver sensitivity and extend the transmission distance. However, correcting bit errors may cause some packet delays. Not all high-speed optical modules recommend enabling this function. For example, it is not recommended to enable FEC when using 100G QSFP28 LR4 optical modules. The FEC function is mainly implemented on the equipment side, so the switch must support FEC. Typically, switches that support FEC have it enabled by default. Note that if the FEC function is enabled on module A, it must also be enabled on module B; otherwise, the interface will not be up.