The equation for SFP (Signal to Noise plus Distortion Ratio) is:

SFP = 20 * log10 (S / (N + D))

Where: S = Signal power N = Noise power D = Distortion power

What does sfp interface meanSFP stands for SMALL FORM PLUGGABLE.

GBIC (abbreviation of Gigabit Interface Converter) is an interface device that converts Gigabit electrical signals into optical signals.GBIC is designed to be hot-swappable.GBIC is an interchangeable product that conforms to international standards. 

Gigabit switches designed with GBIC interfaces have a large market share due to their interchangeability.SFP (Small Form-factor Pluggable) can be simply understood as an upgraded version of GBIC.The SFP port is placed outside the module through CDR and electrical dispersion compensation to compress the size and power consumption. 

It is used in telecommunication and data communication.Types and Functions of SFPSFP transceivers are available in a number of different transmit and receive types, allowing the user to select the appropriate transceiver for each link to provide the "optical performance" that can be achieved based on the type of fiber available (e.g., multimode fiber or single mode fiber). The available optical SFP modules generally fall into the following categories: MMF (SX) at 850 nm/550 m, SMF (LX) at 1310 nm/10 km, XD at 1550 nm/40 km, ZX at 80 km, EX or EZX at 120 km, and DWDM. SFP transceivers also offer copper interfaces, enabling host devices designed primarily for fiber optic communications to communicate over UTP network cables. SFPs for wavelength-division multiplexing (CWDM) and single-fiber "bi-directional" (1310/1490 nm wavelength uplink/downlink) are also available.

Commercial SFP transceivers are capable of delivering rates up to 4.25 Gbps. 10 Gbps transceivers are available in several packages, including XFP, and a newer variant called "SFP+" which is essentially the same package as SFP.

Most optical SFP transceivers support SFF-8472 (Industry Standard Multilateral Protocol), and according to the SFF-8472 protocol, they must support the Digital Diagnostic Monitor (DDM) feature, which allows the end-user to check SFP parameters in real time, such as the basic 5 monitoring quantities: temperature, transceiver power, and power supply. This feature allows the end user to monitor SFP parameters in real time, such as the basic five monitoring quantities: Temperature, Transceiver Supply Voltage (Vcc), Laser Bias Current, Optical Output Power (Tx Power), and Input Power (Rx Power).

Can the sfp interface be directly plugged into a fiber optic?

The sfp interface can be directly plugged into fiber optics. sfp can be simply understood as an upgraded version of GBIC. sfp module, the volume of which is reduced by half compared to the GBIC module, is only the size of a thumb. You can configure more than double the number of ports on the same panel. sfp module's other features are basically the same as GBIC. Some switch vendors call SFP modules miniaturized GBIC (MINI-GBIC)

The composition of the SFP optical module, laser (including transmitter TOSA and receiver ROSA) and circuit board IC and external accessories, external accessories are shell, base, PCBA, pull ring, buckle, unlocking parts, rubber plugs, in order to identify the convenience of the general color of the pull ring to identify the parameters of the module type.