SFP And Its Usages

What is SFP

Telecommunication and/or data communications applications involve vast infrastructure to provide seamless services. There are certain vital parts or equipments that play critical roles in making the networks efficient and robust. SFP (Small form factor pluggable) is one such device which used in both types of communications. It is a compact, hot pluggable transceiver that interfaces a network device mother board to a fiber optic network cable.

SFP is the most popular equipment in telecommunication and data communications industries and it is being jointly produced, developed and supported by almost all major manufacturers across the globe. Their affordability in terms or pricing and multiple advantages have made SFPs to become hot favorites with end-users. Their versatility to support various networks like Gigabit Ethernet, Fiber channel, SONET etc. also made them as a globally accepted product.

SFP Types

There are many types of SFP available in the market. Each type supports the users to provide optical reach on optical fiber type which is available. Both Multimode and Singlemode fiber optics networks can be connected through these SFPs.

SFPs are categorized based on the distance that they can cover, speed at which they work, wavelength that they support. Broadly speaking, following are the categories that we can generally in the market;

SX – Used to cover distance up to 500 meters, 850nm of wavelength and speed at 1.25Gbits/s for Gigabit Ethernet. Whereas for fiber channel network, SX is designed with parameters like 150 meters distance coverage and speed at 4.25 Gbits/s.

LX – Distance up to 10 KM with wavelength of 1310nm

BX – Distance up to 10 KM, with variable wavelengths i.e. 1310nm, 1490nm and 1550nm.

Apart from the above, there are four more varieties like XD (40 KM), ZX (80 KM), EX or EZX (120 KM). All these SFPs come with varied wavelengths and with compatibility with Singlemode and Multimode networks.

SFP Color Codes & Their Meaning

Bare modules SFPs are bit confusing and hence manufacturers follow color codes for easy identification. Following are the details:

Black pull ring is for Multimode with wavelength of 850nm;
Blue module is for 1310nm
Purple color module is for 1490nm.
Yellow module is meant for 1550nm wavelength; and so on.

SFP+ - The Enhanced Version

The extensive R&D in the field of SFPs have led to the introduction of SFP+ which is the enhance version of the standard device currently available in the market. These are distinguished from the rest with their unique capacity of leaving more circuitry for implementation on the host board instead of within the module. SFP+ can be designed with sfp compatibility by making it to accept a standard SFP module.

Advantages of SFP

SFPs are of low cost and versatile. When compared to their previous version called GBIC (Gigabit Interface Converter), sfp port density is much greater which means more number of transceivers can be connected over the edge of a mother board. Thus, SFPs provide excellent and economical solutions for network connectivity.