How does an SFP module work?

How does an SFP module work?

What Is A SFP Module?

SFP is essentially a fibre optic module that fits into an SFP socket or port on an Ethernet switch or media converter. It enables the seamless conversion of Ethernet signals into optical signals for data transfer and reception.

What Is A Transceiver Module?

A transceiver module, such as an SFP, can communicate in both directions. The term "transceiver" is derived from the words "transmitter" and "receiver." As a result, it can function as both a transmitter and a receiver, allowing different devices to communicate with one another. A module's counterpart is the so-called port, into which the module can be inserted. The SFP modules are described in greater detail in the section that follows.

Explaining The SFP Module

SFP is an abbreviation for "small form-factor pluggable," and a transceiver is a device that can transmit and receive data. This topic "SFP Transceivers Explained" is intended to describe everything about SFP transceivers in detail so that network professionals can understand SFP optics and their various types.

The SFP transceiver is a small, hot-swappable device that plugs into a network device's physical port. SFP optics are used in communication networks and have both a transmitting and a receiving side (Tx) (Rx). A laser in the transceiver communicates with the receiving side of the other optic on the other side. SFP optics are intended to support a variety of communication protocols, including SONET, Gigabit Ethernet, and Fibre Channel. SFP interfaces on networking devices like routers provide a modular interface that is easily adaptable to fibre optic and copper networking specifications.

The SFP is also referred to as a miniGBIC. The Gigabit Interface Converter (GBIC) is another transceiver model, and because the SFP is smaller in size than the GBIC, it is called miniGBIC. SFP was developed later than GBIC and serves the same purpose as GBIC modules, but due to its smaller size, SFP has largely replaced GBIC in most applications today. SFP typically includes the LC connector (Lucent connector), whereas GBIC typically includes the SC connector (Standard connector). To clarify, LC and SC connectors are two types of fiber-optic cable connectors that differ in size.

At a given distance, different SFP transceivers use different wavelengths. 1000BASE SFP LX, for example, uses 1310 nm for a maximum distance of 10 km over single-mode fibre, while 1000BASE-ZX can reach 80 km. The copper RJ45 interface is used by 1000BASE-T.

In today's networking environment, many users in various locations must be linked via fibre optic cable to achieve secure communication over long distances. Most of the time, the physical space that they occupy is quite small, so compact devices are required. The demand for SFP modules has increased in recent years as a result of this specific requirement.

What Differentiate the SFP Port?

Individual transceivers can be exchanged using an SFP port in a process known as hot-swap. This means that the modules can be changed while the system is running and thus quickly adapted to the current port. Shutting down the unit or the switch may cause parts of the communication to stop working until they are restarted. The hot-swap option prevents this. If a transceiver fails, it can be replaced quickly and easily without replacing the entire hardware group. As a result, the application allows for a high degree of adaptability.

Which Types of Cables and Plugs Can Be Used?

SFP and QSFP modules are distinguished by their connection type in single mode and multimode fibres. The diameter of the fibre optic cable core varies between single mode (9 m) and multimode (50 m to 62.5 m). For most manufacturers, the color coding of the yoke marks the direct visual distinction. The connector types are primarily determined by the type of transceiver. SFP modules typically include an LC port. QSFP modules with LC or MPO ports GBIC transceivers typically include a SC connector for connection. This should be considered when selecting transceivers and connector types.

What Are the Roles of SFP Modules?

  • SFP modules enable fast communication between switches and network components like routers and other devices.
  • It is most commonly associated with copper or fibre optic cables.
  • Its small size makes it ideal for areas that may not be easily accessible.
  • Compatible with duplex, multimode, single mode, and simplex fibre optic cables.
  • Wavelengths up to 1310nm for Multimode and 1550nm for Single mode are supported.
  • SFP+, a newer version of SFP that offers very high speeds of up to 10Gbps, has been developed.

Types of SFP modules

SFPs are primarily classified according to their speed capabilities. There are several types, including 100Base, 1000Base Gigabit, and 10Gig (SFP+). Most Fiber SFP modules have a transmission speed of 1 Gigabit, but newer versions, such as SFP+, have a higher transmission speed ranging from 10 to 25 Gigabit. Commercially, the modules are denoted by abbreviations such as SX, LX, ZX, EX, and so on. SX denotes a multimode short-wavelength wavelength of 850nm, whereas the others denote single mode wavelengths of varying capacities.

SFP Single-Mode

SMF fibres have a smaller core and a narrow wavelength path. This means that SMF has a higher BW and can cover greater distances. SMF SFPs operate primarily in the 1310 nm and 1550 nm wavelength ranges and have a range of 2 KM to 120 KM.

The following are the SMF Optics:

  • The color-coded bale clasp and label color arrow are typically blue, yellow, or purple.
  • The compatible fibre optic patch cord is yellow in color.

SFP Multi-Mode

MMF has a much larger core and a much longer light wavelength. MMF SFPs are used for short-distance transmissions up to 500 m, and MMF optics are less expensive. MMF SFPs operate at 850 nm wavelength. Although it cannot transport optical signals over long distances, it can transport a variety of optical signals.

  • MMF SFPs, like SMF Optics, are identified by the color of the Bale Clasp.
  • A Multi-mode SFP is identified by a black color-coded bale clasp.
  • The compatible fibre optic patch cord or pigtail is orange in color.

SFP Single-Mode Vs. SFP Multi-Mode

SFP transceivers can communicate with various types of optical fibres. SFP optics that use single-mode optical fibre are known as single-mode SFPs, while those that use multi-mode fibre are known as multi-mode SFPs.

Advantages Of Using SFP Ports on A Gigabit Switch

They are used in network interface cards (NICs), Ethernet switches, firewalls, and other devices to act as an interface between a network device or a device's motherboard and the networking cable. They are also known as mini-Gigabit interface converters (GBIC). You can configure multiple ports on the same panel using an SFP module. Most businesses use switches with at least two or more SFP ports, incorporating them into network topologies such as ring, star, bus, and so on.

How To Select A SFP Module?

  • Consider the following factors when selecting an SFP module:
  • Check the compatibility of the module with the cable and the switch port. This factor can be determined using the abbreviations listed above.
  • Determine whether you require Multimode or Single mode modules.
  • Check that it complies with IEEE standards.
  • Determine the distance or area that must be covered. Depending on this, you would select either short or long-distance data transmission.
  • What kinds of environmental factors must be considered? Take into account the operating temperatures in your application and make your selection accordingly.
  • Check for features such as electrostatic discharge protection in addition to the operating temperature range.






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