SFP and SFP+ Optical Modules Compatibility

SFP modules have different capabilities and/or form factor size. SFPs gave the fiber installations total flexibility, in that a cage could hold any fiber type/appropriate speed. Fixed fiber transceivers are still cheaper, but SFPs are decreasing in cost all the time. 10G transceivers are available in SFP+ and XFP. One cannot install a 10G SFP+ into a device supporting 1 Gig and expect it to work. And that is not taking into account the fit check (different sizes dimensionally)!

The Technology of SFP+ Transceivers Are More and More Mature

Older SFP optical transceivers usually operate at lower wattages but newer SFP+ optical transceivers operate at higher wattages. Commercially available optical transceivers are rated up to 70°C, but there are extended-temperature-range transceivers that can operate up to 85°C. Newer SFP+ modules that are used in both short-reach and long-reach applications are still dissipating 1 watt or less, but extended reach and fixed DWDM (dense wavelength division multiplexing) transceivers can range from 1.25 to 1.5 watts per port. The particular short-reach (SR) fiber optic transceiver explores multi-mode soluble fiber to be able to broadcast concerning 100m length. As well as the long-reach (LR) soluble fiber optic element, which usually explores single-mode soluble fiber, transfers 100m to be able to 10km length.

SFP and SFP+ Compatibility

SFP+ transceiver will be 10GBaseSR, 10GBaseLR, 10GBaseLX, etc..
SFP will be 1GBaseSR, 1GBaseLR, 1GBase LX, etc...
Those protocols are not intercompatable.
You can install an SFP module in an SFP+ slot, but you cannot connect an SFP module to an SFP+ module. Many SFP+ (10GbE) sockets can step-down to 1Gbps operation, but you must use a 1GbE SFP.
You cannot configure a 10GbE SFP+ module to operate at 1GbE speeds.

SFP and SFP+ optical modules are used for both telecommunication and data communication. They connect switch, router, or other network devices to a fiber cabling plant. SFPs can be found in metro access network, metro core network, Wide Area Networks, etc. They designed for most of the fiber networking standards such as SDH/SONET, Ethernet, Fibre Channel, etc.