QSFP-40G-SR-BD Transceiver: An Ideal Option for 40G Ethernet


The demands for higher bandwidth, larger capacity and greater performance in the network are still increasing fiercely. Hence, the migration from 10G to 40G has become a significant and inevitable option for network service providers. Well, this article will recommend an ideal option for you to get 40G Ethernet: QSFP-40G-SR-BD.

QSFP-40G-SR-BD Transceiver Overview

QSFP-40G-SR-BD transceiver, known as a type of QSFP 40-Gbps BiDi transceiver, is a standard QSFP+, MSA compliant optical transceiver. It is designed to work at the wavelength from 832 nm to 918 nm and has a duplex LC interface. What’s more, QSFP-40G-SR-BD transceiver supports the transmission distance of 100m and 150m over a laser-optimized OM3 or OM4 multi-mode fiber (MMF). So this module is commonly used for short-reach data communication.

Picture of an optical transceiver
Figure1: QSFP-40G-SR-BD
Operational Principle of QSFP-40G-SR-BD Transceiver

Bidirectional Optical Sub-Assembly (BOSA) technology is now available that allows components to both transmit and receive optical signals at the same time. By using BOSA, QSFP-40G-SR-BD transceiver can provide two different wavelengths on each fiber transmit 40Gbps data over the traditional 10G MMF cabling.

In the QSFP-40G-SR-BD transceiver, there are four 10Gbps signal channels which are converted to two bidirectional channels of 20Gbps signals. Each 20Gbps signals are transmitted over two different wavelengths (usually 850nm and 900nm). As shown in the following:

QSFP-40G-SR-BD using duplex LC MMF
Figure2: QSFP-40G-SR-BD using duplex LC MMF

Advantages of SFP-40G-SR-BD 40G Transceiver

  • Easier for upgrading to 40G -With QSFP-40G-SR-BD transceiver, it is easier to rescue existing 10G fiber infrastructure for higher speed 40G cable connections. And you don’t need to upgrade cabling or rewire your data center for larger capacity anymore.
  • Cost-saving – If you set up the 40G data center fabric in a traditional way, you may need much more fibers. Take the 40GBASE-SR4 transceiver as an example, it requires eight fibers for 40G Ethernet. While QSFP-40G-SR-BD transceiver just requires two fibers but can meet the 40GBASE-SR4 performance criteria. So with a QSFP-40G-SR-BD transceiver, there is no need for you to add more fibers.
  • Time-saving – As has been mentioned above, 10G Ethernet is too slow to meet the demand for great performance in the network. With QSFP-40G-SR-BD 40G transceiver, you can get 40G Ethernet, which is faster than before. That is to say, you can save more time to get what you need in the network.


QSFP-40G-SR-BD 40G Transceiver is an ideal and feasible option for 10G Ethernet to 40G Ethernet migration. By using the QSFP-40G-SR-BD 40G transceiver, it is unnecessary to update the fiber infrastructure with high-cost money and long time.

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