In the last passage, we have gained a deep and comprehensive understanding of 10 Gigabit Ethernet. Next, we will shed light on 40 Gigabit Ethernet which was introduced by the IEEE 802.3ba in 2010. 802.3ba is the designation given to the higher speed Ethernet task force which completed its work to modify the 802.3 standard to support speeds higher than 10 Gbit/s. 40G is slowly taking the place of the 10G network market as the latter is becoming out-dated due to its slow speed and other shortcomings. Therefore, it is beneficial to study the 40G transceivers in detail.

40G Transceiver: QSFP+ Module

A 40G optical module is a derivative product capable of delivering high density ports and considerable data transmission speed. It is a high performance, hot-pluggable interconnect solution finding its rampant use in data centers. An integrated model of four independent transmit and receive signals work coordinately to deliver the high density but power-efficient 40G Ethernet connectivity. The 40G applications, apart from in data centers, are also being used widely in high performance computing networks, enterprise core and distribution layers, and telecom operators. The new demands of 40G transceiver modules pushed the high-speed optical transceiver market to grow. This article would put emphasis on introducing 40G optical transceiver, especially the QSFP+ module.

What’s 40G QSFP+ Module?

The 40G QSFP+ module is a hot-swappable, parallel fiber optical module. The 40G QSFP+ transceiver complies with the Ethernet, Fibre Channel, InfiniBand, and SONET/SDH standards. It adopts four 10Gbit/s transmission channels to transmit data and the transmission of four channels can get 40Gbps at the same time. In addition, 40G QSFP+ connector can be either duplex LC or 12-fiber MTP/MPO connector.

Types of 40G QSFP+ Module

In this part, three kinds of 40G QSFP+ transceivers will be introduced respectively, that is, QSFP 40G SR4, QSFP BiDi, QSFP 40G LR4.

QSFP 40G SR4, Short-reach (SR) transceivers for 40G connectivity in a QSFP form factor, uses independent transmitter and receiver sections, each with 4 parallel fiber strands. It can transmit 150 meters over OM4 MMF. For a 40G connection, 8 fiber strands are required, and 12-fiber MPO connectors are used.

The QSFP BiDi transceiver is a short-reach optical transceiver that delivers 40 Gbps over a duplex OM3 or OM4 MMF connection, which can reach 100 meters on OM3 or up to 150 meters over OM4. It has two 20G channels, each transmitted and received simultaneously on two wavelengths over a single MMF strand.

The QSFP 40G LR4 Module supports link lengths of up to 10km over a standard pair of G.652 single-mode fiber with duplex LC connectors. The 40 Gigabit Ethernet signal is carried over four wavelengths. Multiplexing and demultiplexing of the four wavelengths are managed within the device.

Conclusion

As is shown in the table, there are many types of QSFP+ transceivers. We(www.fs.com) offer a wide range of 40GBASE QSFP+ optical modules that are compatible with major brand network devices, and can also provide OEM customized services. All of our 40G QSFP+ optical modules are tested in multiple performances at the test center for superior performance.