What is a Loopback Transceiver?

What is a Loopback Transceivers ?

If you ever wondered how to test the ports of your switches or serves, the answer is using a loopback transceiver ! It’s the simplest way and most low cost solution on the market for ports testing.


The best solution for testing switches and servers ports is the passive electrical loopback transceiver. It works by simulating the communication between two devices by transmitting the data (output) and receiving it (input).

Loopback perfectly replicate the performance of typical 10G SFP+, 40G QSFP+, 25G SFP28, 100G QSFP28 and 400G QSFP-DD connections between equipped adapter cards, blade servers, routers, and switches. Even if they are able to duplicate the operational characteristics of typical transceivers, they do not contain the expensive components found in transceivers, such as the chips or laser diodes. That is why the cost of loopback is so low.

Optech Technology Loopback Transceivers

Optech‘s Loopback Transceivers serie includes, 10G SFP+ Loopback, 40G QSFP+ Loopback, 25G SFP28 Loopback,100G QSFP28 Loopback and 400G QSDFP-DD Loopback.

10G SFP+ Loopback Transceiver for SFP+ port testing

10G SFP+ Loopback transceiver

25G SFP28 Loopback Transceiver for SFP28 port testing

25G SFP28 Loopback Transceiver

40G QSFP+ Loopback Transceivers for QSFP+ port testing

40G QSFP+ Loopback

100G QSFP28 Loopback Transceivers for QSFP28 port testing

100G QSFP28 Loopback transceiver

400G QSFP-DD Loopback Transceivers for QSFP-DD port testing

400G QSFP-DD loopback


Our Loopback are cost effective and high quality solutions to test transceivers ports. Customized signal attenuation and power are available upon request.

Technology Optech Part Number Features
10G SFP+ Loopback  OPSFPP-T-00-PX 0 Dbm
25G SFP28 Loopback  OPSF28-T-00-PX  0 Dbm
40G QSFP+ Loopback  OPQSFP-T-00-PX  0 Dbm
100G QSFP28 Loopback  OPQS28-T-00-PX  0 Dbm
400G QSFP-DD Loopback OPQSDD-T-00-PX 0 Dbm

For more technical information about the 400G QSFP-DD Loopback click here.

About Optech

Optech Technology Co. Ltd was founded in 2001 in Taipei, Taiwan. The company was created with a sole purpose, to provide a wide and high quality portfolio of optical products to a very demanding and fast evolving market.

To respond to the permanent increase of IP traffic, Optech portfolio is constantly growing. Since the beginning, the company has always been up to date with the latest innovations on the market. Today, we are proud to deliver a large selection of 25G SFP28, 40G QSFP+, 100G QSFP28 and 400G QSFP-DD optical transceivers and cables.

Optech has a large portfolio of products which include optical transceiversdirect attach cablesactive optical cablesloopback transceiversmedia converters and fiber patch cords.

Through its large selection of optical products, that have a range of data speed from 155 Mbps to 400 Gbps and reach distances up to 120km, Optech products are suitable for various industries such as telecom, data centers as well as public and private networks.

This Post Has One Comment

  1. Myron

    I would like to know how to use Loopback Transceiver validation ?
    Could you recommend me some tool or application?

Leave a Reply