Can Gigabit SFP optical modules be used on 10 Gigabit SFP + ports?

According to the experiment, the Gigabit SFP optical module can operate in the 10 Gigabit SFP + port, but the 10 Gigabit SFP + optical module cannot operate in the Gigabit SFP port. When a Gigabit SFP optical module is inserted into a 10 Gigabit SFP + port, the speed of this port is 1G, not 10G. Sometimes this port will be locked at 1G speed until you reload the switch or issue some commands. So in most cases, the SFP optical module can be inserted into the SFP + port.

In addition, SFP + ports generally do not support speeds below 1G. That is to say, we cannot insert 100BASE SFP optical module on the SFP + port. In fact, for this problem, it depends largely on the Switch Switch model. Some SFP + ports can support SFP, some do not. For example, almost all SFP + ports of all Cisco CISCO switches support SFP optical modules, and many SFP + ports of Brocade switches only support SFP +. Although it is often feasible, it is still safer to follow the information provided by the Switch vendor.

10G SFP + cannot be automatically compatible with Gigabit SFP optical modules

In many cases, we can use SFP optical modules in SFP + ports, but this does not mean that SFP optical modules inserted in SFP + ports can support 1G. In the optical fiber link, if we connect the SFP optical module and the SFP + optical module, it may not work properly! For this problem, if you use SFP + high-speed cable, it cannot be incompatible with Gigabit SFP.

The SFP and SFP + optical modules used in network cabling and data center computer room construction need to ensure the same speed at both ends of the fiber link. For example, the SFP + port on one end uses the 10G SFP + 1310nm 10KM LC DDM optical module, and the other end uses the same optical module. The single-fiber optical modules need to be paired .

SFP single-fiber optical module transmission wavelength:

① Tx1310 / Rx1550nm, Tx1550 / Rx1310nm;

② Tx1490 / Rx1550nm, Tx1550 / Rx1490nm.

SFP + single fiber optical module transmission wavelength:

① Tx1270 / Rx1330nm, Tx1330 / Rx1270nm

② Tx1490 / Rx1550nm, Tx1550 / Rx1490nm).