Table of Contents
Q: What is a QSFP28 optical module?
A: QSFP28 optical module is a high-speed optical module applied to 100G Ethernet. It adopts the package form of QSFP28 and is small in size. The QSFP28 optical module has four signal channels, and the maximum transmission rate of each signal channel is 28Gbps. It has a variety of transmission distances to choose from. Among them, the QSFP28 optical module used in the InfiniBand system is called EDR, and the QSFP28 optical module of EDR has stricter performance requirements.
Q: What are the main application scenarios of QSFP28 optical modules?
A: QSFP28 optical modules are mainly used for 100G connections of core switches and core routers in data centers.
Q: Can QSFP28 optical module ports use QSFP+ optical modules?
A: For most switches, QSFP+ optical modules can be used for QSFP28 ports.
The external dimensions of the QSFP28 optical module are the same as that of the QSFP+ optical module, but the transmission mode of the former is 4x25G or 4x28G, and the transmission mode of the latter is 4x10G.
Q: What is the difference between SFP28 optical module and QSFP28 optical module?
A: The transmission rate is different; the packaging form is different; the working principle is different.
The transmission rate of SFP28 optical module is 25Gbps; the transmission rate of QSFP28 optical module is 100Gbps;
SFP28 optical module adopts SFP28 package; QSFP28 optical module adopts QSFP28 package;
The SFP28 optical module adopts single-channel transmission, and the transmission rate is 25Gbps; the QSFP28 optical module adopts four-channel transmission, and the transmission rate of each channel is 25Gbps, and the total transmission rate is 100Gbps.
Q: What is the difference between QSFP28 CWDM4 optical module and QSFP28 LR4 optical module?
A: The wavelengths are different.
The operating wavelengths of QSFP28 LR4 optical modules are 1295nm, 1300nm, 1305nm, 1310nm, and the wavelength interval is 5nm;
The operating wavelengths of QSFP28 CWDM4 optical modules are 1271nm, 1291nm, 1311nm, 1331nm, and the wavelength interval is 20nm;
QSFP28 LR4 optical modules and QSFP28 CWDM4 optical modules have different wavelengths and cannot communicate with each other.
Q: When using a pair of QSFP28 CWDM4 optical modules, do I need to enable the forward error correction (FEC) function?
A: When using the QSFP28 CWDM4 optical module, both ends need to turn on or off the FEC function at the same time (the FEC function is turned on to reduce the bit error rate).
Q: What is the main difference between QSFP28 CWDM4 optical module and 100G CLR4 optical module?
A: The main difference is whether the forward error correction (FEC) function is supported. For the QSFP28 CWDM4 optical module, it is necessary to support the forward error correction function; but for the 100G CLR4 optical module, the forward error correction function is optional, it can enable the forward error correction function to increase the link redundancy amount, or turn off forward error correction to maintain low-latency and low-power performance.
Q: What is the difference between QSFP28 CWDM4 optical module and QSFP28 PSM4 optical module?
A: Both QSFP28 CWDM4 and QSFP28 PSM4 optical modules can transmit on four wavelengths. However, the QSFP28 PSM4 optical module uses four independent wavelengths to transmit signals through an 8-core MTP/MPO single-mode fiber patch cord. The QSFP28 CWDM4 optical module uses wavelength division multiplexing technology to multiplex four wavelengths on a single fiber for transmission, so only 2-core LC duplex single-mode fiber jumpers can be used to achieve 100G transmission.
Q: What is the power consumption of the QSFP28 CWDM4 optical module?
A: The maximum power consumption of the QSFP28 CWDM4 optical module is 3.5W.
Q: Do I need to clean the connector of the QSFP28 CWDM4 optical module?
A: Yes, dust and pollutants will accumulate on the connector of the QSFP28 CWDM4 optical module, which may cause the problem of reducing the transmitted optical power. To ensure the stability of transmission, it is recommended that you clean the connector of the QSFP28 CWDM4 optical module every time you disconnect and reconnect.