SFP optical modules are smaller in size and lower in cost than XFP optical modules. Why do some devices use 10G optical modules or XFP optical modules?

　　In fact, this is not the case, xfp is an older generation product and consumes more power! But there are also SFP+ ones, like the Nexus switch series. In addition, the low-end 2960S and 3750X are also SFP+, and XFP is an early product, which is large and easy to dissipate heat, especially 80km, but cannot meet the volume requirements of high-density boards for optical modules, because SFP and XFP are different The package form of the module itself is different in size. If the interface board interface is adapted to SFP, then the XFP module is specified to be unable to be inserted; vice versa.

　　Therefore, the interconnection of optical fiber modules must ensure the same speed and the same parameters. If it is the same package; some high-speed ones are backward compatible with low-speed ones. It depends on the specific situation