SFP+ modules are not typically backwards compatible with older SFP modules due to differences in their electrical and mechanical specifications. However, some networking equipment and transceivers may support both SFP and SFP+ modules, allowing for a degree of backwards compatibility in certain scenarios. It is best to consult the specifications of your specific networking equipment to determine its level of compatibility with SFP and SFP+ modules.

Can 1G SFP Optics Run at 10G SFP+ Port?

SFP+ slots can take SFP modules, most do but not all. It may depend greatly on the switch models. SFP+ ports often accept SFP optics but at a reduced speed of 1Gb. And sometimes this port will lock the speed at 1Gb until you reload the switch or do some fancy set of commands. Besides, the SFP+ port usually don't support speed under 1G. That is to say, you can't plug the 100BASE SFP in the SFP+ port.

If you are unsure about the connectivity, it is suggested that you consult the vendor to make sure the 10Gb switch port supports dual rate before plugging an SFP transceiver into the SFP+ port on your 10Gb switch.

Choose SFP or Advanced SFP+?

SFP and SFP+ are applied at different transmission speeds. SFP module supports 1Gb data rate, and the SFP type includes 1000base-T/TX, 1000base-SX, 1000base-LX/LX10, 1000base-BX10, 1000base-LX/LH, 1000base-EX, 1000base-ZX and so on.

SFP+ is used in 10-gigabit Ethernet applications but shares the same form factor with SFP. In the SFP+ family, there are primarily SFP+ SR, SFP+ LR, and SFP+ ZR modules for 10 Gigabit ethernet networking.

Choose an MSA Compatible SFP or Not?

Compatibility is often the most important parameter users care about when buying an MSA SFP module. MSA (multi-source agreement) is an agreement supported by a number of manufacturers who came together to collaborate and standardize the fit-form and try to provide a reliable mean of mixing and matching SFP brands successfully. Third-party companies also have developed their own tools to program SFP modules to be compatible with the OEM. So, the MSA compatibility Gigabit SFP module can be used successfully in most networks.

SFP vs. SFP+

Here is a table of comparison between SFP and SFP+