Datasheet of 40G QSFP Module

When it comes to selecting 40G QSFP modules, customers may be dazzled by the various products provided by various suppliers. Some of them may directly purchase from big brands like Cisco. Actually, except for those well known brands, many other rising companies like FS also provide 40G QSFP module, which usually come at a much lower price with with a high quality. This post will demonstrate the 40G QSFP Datasheet provided by FS.

40G QSFP Module Datasheet: QSFP 40G SR4 Datasheet

The S-Class FS 40GBASE-SR4 QSFP module supports link lengths of 100 and 150 meters, respectively, on laser-optimized OM3 and OM4 multimode fibers. QSFP 40G SR4 transceiver is aligned to IEEE 40GBASE-SR4 optical specifications which support high-bandwidth 40G optical links over 12-fiber parallel fiber terminated with MPO/MTP multifiber female connectors. Because IEEE 40GBASE-SR4 does not support 4x10G breakout connectivity to 10GBASE-SR, see QSFP-40G-SR4 or QSFP-40G-CSR4 for such applications. QSFP 40G SR4 does not support FCoE. More specific details of FS QSFP 40G SR4 can be obtained in the table below.

qsfp module- qsfp 40g sr4 datasheet

40G QSFP Module Datasheet: QSFP 40G LR4 S Datasheet

The FS 40GBASE-LR4 QSFP module supports link lengths of up to 10 kilometer over a standard pair of G.652 SMF (single-mode fiber) with duplex LC connectors. The QSFP-40G-LR4-S module supports 40GBASE Ethernet rate only. The 40 Gigabit Ethernet signal is carried over four wavelengths. Multiplexing and demultiplexing of the four wavelengths are managed in the device. QSFP-40G-LR4-S does not support FCoE. More information have been shown in the following QSFP 40g LR4 S.

qsfp module-qsfp 40g lr4 datasheet

QSFP+ SR4 vs QSFP+ LR4: Which One to Choose?

After going through QSFP 40G SR4 Datasheet and QSFP 40g LR4 S Datasheet, you may have had a basic understanding of QSFP 40G SR4 and QSFP 40g LR4. SR is short for short reach and LR represents Long Reach. The most obvious difference is that 40GBASE-SR4 is with MPO/MTP port while the 40GBASE-LR4 is with the Duplex LC port. The cost of 40GBASE-SR4 QSFP+ is more cheaper than the 40GBASE-LR4 QSFP+. Additionally, the fiber cost of the cabling with them also have a big difference. Because SMF cabling is more expensive than the MMF cabling.


As speeds have increased to 40G, the quad small form-factor pluggable (QSFP) has become the high-density transceiver of choice. Hoping this post on FS 40G QSFP Datasheet may help you when selecting 40G optical transceivers.

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40G QSFP+ LR4 Transceiver—An Ideal Choice for 40G Network