SFP Transceivers all the things you need to know

What do we need to know about an SFP Transceiver?

A Small Form-factor Pluggable transceiver often referred to as an SFP.

This type of transceiver is known as a hot-swappable, compact module that can plug into any SFP port.

If a switch or router has this port it means that the SFP fibre transceiver can interface between these communication devices.

The job of an SFP transceiver is to convert between optical (fibre) and electrical signals (copper).

Also referred to a mini GBIC because the SFP transceiver's function is the same as the GBIC transceiver, it's just much smaller.

SFP Transceiver

SFP Transceiver

SFP Transceiver inside view

Most SFP transceivers have two ports, one port to transmit data and one port to receive data.

SFP Circuit boardSFP Connector

One port has a laser transmitter side and the other port has a photodetector which is the receiving side.

A bi-directional SFP however only requires one port as the picture below shows.

It is designed to transmit data using one wavelength and to receive data using another wavelength.

SFP TransceiverBi-Directional SFP Connector

How do you Install an SFP into the SFP port or SFP Slot?

Below image displays an SFP Port or an SFP slot with an SFP being inserted and an empty SFP port.

SFP Transceiver  

To insert an SFP or SFP+ module into a module port, do the following:

1    -  Line up the module with the port.

      -  Position the SFP correctly prior to installing it.

      -  Do not remove the dust caps on the end of the optical SFP or SFP+ modules until installed and ready for cable connection.

         This is to avoid getting any dust or contamination into the optics of the modules.

         The module may not work correctly if obstructed with dust.         

     -  Without much force slide the module into the port until it clicks into place.

     -   When ready to use remove the dust caps and connect the Fibre Optic cable required.

How do you remove an SFP from the SFP port or SFP Slot?

To remove an SFP  transceiver or SFP+ transceiver from an SFP port do the following:

  1. Remove the fibre cable connected to the SFP or SFP+ module, if there is one.

  1. Identify the release mechanism for the SFP and release (Pull the lever down)

  1. Take the module between your thumb and index finger, and carefully pull it out of the port.

SFP Transceiver

How do we classify SFP Modules?

SFP modules can be classified based on the working wavelengths and working distances.

Example for wavelengths

SR  ("short-range") is a  multi-mode fibreport type and uses 850 nm lasers.

LRM (Long Reach Multimode) is a multi-mode fibreport type and uses 1310 nm lasers

LR ("long reach") is a single-mode fibre port type and uses 1310 nm lasers

ER ("extended reach") is a single-mode fibre port type and uses 1550 nm lasers

ZRSome manufacturers have introduced 80 km range ER pluggable interfaces.


The world of SFP transceivers is a tricky one.

You definitely need to know what is required from the SFP module to make it work.

For a list of available SFP modules go to our website www.fibresales.com.au or click on the easy link below.

Call us on (03) 9761 7925 if you need any further assistance.

FibreSales Banner