40GBASE-SR4 and 40GBASE-LR4 FAQs

When you are building high-density 40G Ethernet, 40G QSFP+ optical modules are indispensable. You may be confused about many different models. Currently, the more common types are 40GBASE-SR4 and 40GBASE-LR4. In this article, we will Mainly discuss 40GBASE-SR4 and 40GBASE-LR4 and answer a series of questions about 40GBASE-SR4 optical transceivers. Through this article, you will know more about 40GBASE-SR4.

 

What is a 40GBASE-SR4 Transceiver?

 

40GBASE-SR4 is also called QSFP-40G-SR4, which is used for 40G Ethernet short-distance transmission, and \”SR\” refers to short-reach. QSFP+ SR4 optical module complies with IEEE 802.3ba 40GBASE-SR4 standard, designed with an MPO/MTP optical fiber connector, it can transmit up to 100m when used with OM3 MMF fiber and up to 150m when used with OM4 MMF fiber.

 

There are independent transmitting and receiving parts inside the QSFP-40G-SR4 optical module, and each part has 4 parallel channels. When 40GBASE-SR4 optical modules are used for 40G connection, all 8 fibers are required and optical fiber with MTP/MPO-12 fiber connectors. Therefore, each link will have 4 fibers idle.

 

What is a 40GBASE-LR4 Transceiver?

40GBASE-LR4 can also be called QSFP-40G-LR4, which is also used for 40G Ethernet transmission like 40GBASE-SR4. QSFP+ LR4 optics are IEEE 802.3ba 40GBASE-LR4 compliant and feature LC duplex connectors for long-reach (LR) transmission of up to 10 km over single-mode fiber. The QSFP-40G-LR4 optical module uses the same form factor as 40GBASE-SR4, and also provides four independent transceiver channels, each with a bandwidth of 10Gbps.

 

In order to transmit 4-channel signals on single-mode fiber, the 40G LR4 optical module must multiplex or demultiplex the optical signals through the internal MUX/DEMUX.

 

FAQs

What is the difference between 40GBASE-SR4 and AOC?

 

40G AOC active optical cables are used for 40G short-haul applications like 40GBASE-SR4 optical modules. The difference is that QSFP+ AOC is a pre-terminated optical cable, one end is connected to 40GBASE-QSFP+, and the other end can be connected to SFP+ connectors, LC connectors, etc. in addition to QSFP+ connectors. The transmission distance of 40G AOC is generally not more than 100m.

 

What is the difference between QSFP-40G-LR4 and QSFP-40G-PLR4?

 

QSFP-40G-PLR4 is also called QSFP-40G-LR4 PSM in the industry. The main difference between 40GBASE-LR4 and 40GBASE-PLR4 is their interfaces and supported protocols. The 40GBASE-PLR4 module is based on the IEEE 802.3ae 10GBASE-LR standard with MTP/MPO connectors, while the 40GBASE-LR4 module is based on the IEEE 802.3ba 40GBASE-LR4 standard with an LC duplex connector.

 

How to distinguish 40GBASE-ER4 and 40GBASE-LR4?

 

Conclusion

 

Through the introduction of this article, we know some common problems about 40GBASE-SR4, and also solve some common problems about 40GBASE-SR4 and 40GBASE-LR4, these two optical modules have different applications, if you If you want to know more about 40GBASE-SR4, you can contact QSFPTEK customer service via sa***@*****ek.com, QSFPTEK is a company specializing in the production of cost-effective and high-quality optical modules and related products.