In recent years, cloud computing and big data have created a boom in China, and in order to provide sufficient bandwidth, many access switches have evolved to core switches that can connect to 40G Ethernet. The rapid development of interconnecting data transmission cannot be separated from 40G optical modules, as it can provide enough bandwidth to ensure unimpeded data conversion to meet the needs of data centers and enterprise campuses for networking.

With four mutually independent channels for transmitting and receiving optical signals, 40G optical modules are able to provide high-density and low-power 40G Ethernet connectivity transmission applications for data centers, high-performance computing networks, enterprise core and distribution layers, and telecom carriers.

I. Classification of 40G Optical Module

Currently on the market, 40G optical modules are more common CFP and QSFP + optical module categories.

1, 40G CFP optical module is designed for 40G Ethernet links on single-mode fiber, RoHS-6 compliant, and provides digital diagnostics through the CFIO MSA designated MDIO interface;

2. 40G QSFP+ Optical Module is a product developed on the basis of QSFP, specialized for high-density applications, with higher port density and lower overall system cost compared with traditional SFP+ Optical Module. It has four data transmission channels, the transmission rate of each channel is about 10Gbps, and four channels at the same time can realize 40Gbps transmission rate.

Second, 40GQSFP+ optical module introduction and application

QSFP-40G-SR4 Optical Module

1, 40G SR4 QSFP + optical module: the center wavelength of 850nm, MPO / MTP interface, multi-mode, support for DDM, the operating temperature of 0 ° C ~ 70 ° C, transmit optical power of -7.6 to +0.5dBm, commonly used in data centers.

Patch cord with program: 1, with OM2, the maximum transmission distance is 30M. 2, with OM3, the maximum transmission distance is 100M. 3, with OM4, the maximum transmission distance is 150M.

QSFP-40G-eSR4 Optical Module

2, 40G eSR4 QSFP + optical module: the center wavelength of 850nm, MPO / MTP interface, multi-mode, support for DDM, the operating temperature of 0 ° C ~ 70 ° C, the transmission optical power of -7.6 to +0.5dBm, commonly used in 40G Ethernet and metro optical transport network.

Patch cord matching scheme: 1, with OM2, the maximum transmission distance is 82M. 2, with OM3, the maximum transmission distance is 300M. 3, with OM4, the maximum transmission distance is 400M.

QSFP-40G-PSM4 Optical Module

QSFP-40G PSM4 QSFP+ Optical Module: center wavelength is 1310nm, MPO/MTP interface, single-mode, support DDM. 40G PSM4 QSFP+ Optical Module is generally used with single-mode patch cords OS2 in the interconnection solution of 40G Ethernet, Fibre Channel and PCIe, and the transmission distance can be up to 2KM.

QSFP-40G-LR4 Optical Module

4, 40G LR4 QSFP + optical modules: the center wavelength of 1271nm, 1291nm, 1311nm, 1331nm, duplex LC interfaces, single-mode, support for DDM, the operating temperature of 0 ° C ~ 70 ° C, the transmitter optical power of -7 to +2.3dBm. Generally used with single-mode jumper OS2 for data center interconnections and metro optical transport network, transmission distance up to 10KM. The transmission distance is up to 10KM.

5, 40G LR4 QSFP + optical module: center wavelength of 1310nm, MPO interface, single mode, support DDM, operating temperature 0-70 degrees Celsius. Generally used with single-mode patch cords OS2 between data centers and Internet exchange points, transmission distance up to 10KM.

V. QSFP-40G-ER4 Optical Module

6, 40G ER4 QSFP + optical module: the center wavelength of 1271nm, 1291nm, 1311nm, 1331nm, duplex LC interface, single mode, support for DDM, the operating temperature of 0 ° C ~ 70 ° C, the transmission optical power of -2.7 to +4.5dBm, usually with single-mode patch cord OS2 used in data centers and metropolitan optical transmission network, the transmission distance up to 40KM. The transmission distance is up to 40KM.

QSFP-40G-SR-BD Optical Module

7, 40G BIDI QSFP + optical module:the central wavelength of 850nm, 900nm, duplex LC interface, multimode, support for DDM, operating temperature of 10 ° C ~ 70 ° C, transmit optical power of -4 to +5dBm. The optical module actually uses two 20G single-fiber bi-directional technology for sending and receiving, you need to use the LC interface of the two multimode fiber.

Patch cord with the program: 1, with OM3, the maximum transmission distance of 100M. 2, with OM4, the maximum transmission distance of 150M.

Third, the summary

Finally, the emergence of 40G optical modules to simplify the network architecture, reducing the number of accessories, Walsun as a manufacturer of optical modules, the above products are available, the products are compatible with Huawei, Cisco, H3C, Ruijie and other brands of switches.

In the application of metro backbone network, its scheduling and integration are much better than 4 10G systems, which can save the server room area, reduce equipment stacking and improve the bandwidth management and scheduling ability of single node equipment, effectively reducing the cost, more economical than other metro network solutions.

Additional Learning Hub Resources 

QSFP-DD Optical Module Wiki 

QSFP28 Optical Module Wiki 

QSFP Optical Module Wiki 

Tunable SFP+ Transceiver Wiki 

10G BIDI SFP+ Optical Modules Wiki 

DWDM SFP+ 10G Optical Module Wiki 

CWDM SFP+ 10G Optical Module Wiki