The compact optical module is an SFP packaged hot-plug small package module. Its main function is to convert the electrical signal at the sending end into an optical signal and transmit it. After receiving the information, the receiving end restores the optical signal to an electrical signal.
The compact optical modules are classified according to the rate: 155M / 622M / 1.25G / 2.125G / 4.25G / 8G / 10G, of which 155M and 1.25G are more used in the market.
According to the wavelength classification: 850nm / 1310nm / 1550nm / 1490nm / 1530nm / 1610nm, the wavelength is 850nm for multimode, the transmission distance is below 2KM, the wavelength is 1310 / 1550nm for single mode, the transmission distance is above 2KM.
According to the distance classification: short distance, middle distance, long distance.
Classified according to the transmission mode: electrical port, single mode, multi-mode.
The special types of compact optical modules also include: BIDI-SFP, electrical port SFP, CWDM SFP, DWDM SFP, SFP + optical module, etc.
Compact optical modules can operate in SFP + slots, but SFP + optical modules cannot operate in compact optical module slots. SFP + ports usually cannot support speeds below 1G. In other words, we cannot insert a 100BASE SFP optical module into the SFP + port. In fact, for this problem, it depends largely on the switch model.
However, SFP + optical modules cannot be automatically compatible with 1G to support SFP optical modules. Unlike copper SFPs available in 10/100/1000 automatic compatibility, optical fibers such as SFP and SFP + do not support automatic compatibility. Although in many cases we can use a compact optical module in the SFP + port, but this does not mean that it can automatically support 1G by plugging in the SFP + port. In the optical fiber link, if we insert a compact optical module in the SFP + port (1G) on one side and then insert an SFP + optical module in the SFP + port on the other side (10G), it may not work properly.
When using compact optical modules and SFP + optical modules in the network, ensure that the speeds of both ends of the fiber link are the same. Compact optical modules can be used in SFP + ports, but compact optical modules cannot be connected to SFP + optical modules.
