Super complete knowledge of QSFP+ direct connect cable

Direct connection cable is an ideal short-distance connection solution to replace optical modules. It is divided into two categories: high-speed cable (DAC) and active optical cable (AOC). extensive attention. Now, with the rise of 40G networks, QSFP+ direct-connect cables are gradually becoming popular. This article will introduce in detail the 6 types of QSFP+ direct connect cables commonly found in the market.

QSFP+ Direct Connect Cable

40G QSFP+ high-speed cable (DAC)

40G QSFP+ high-speed cable (DAC) uses copper cable as the transmission medium, and there are two types of passive and active. The 40G QSFP+ passive high-speed cable (DAC) does not require power supply and has lower power consumption, but the transmission distance is also shorter; the 40G QSFP+ active high-speed cable (DAC) has a longer transmission distance. According to the different connectors at both ends of the copper cable, the 40G QSFP+ high-speed cable (DAC) can also be divided into the following types:

40G QSFP+ to QSFP+ High Speed ​​Cable (DAC)

Both ends of this high-speed cable (DAC) are pre-terminated with QSFP+ connectors, which are suitable for connecting two 40G network devices. The passive transmission distance is generally less than 5m, and the active transmission distance is longer. The specific number Varies by manufacturer.

40G QSFP+ to 4xSFP+ high-speed cable (DAC)

One end of this high-speed cable (DAC) is pre-terminated with a QSFP+ connector, and the other end is pre-terminated with four 10G SFP+ connectors, which are used to connect 40G devices and 10G devices, and are suitable for 10G and 40G network connections.

40G QSFP+ to 4xXFP High Speed ​​Cable (DAC)

Compared with the first two types of 40G QSFP+ high-speed cables (DAC), this type of high-speed cable (DAC) is not common. It has a QSFP+ connector on one end and 4 XFP connectors on the other end.

40G QSFP+ Active Optical Cable (AOC)

40G QSFP+ active optical cable (AOC) uses optical cable as the transmission medium, which has the characteristics of light weight and long transmission distance. In addition, there is no need to worry about electromagnetic interference (EMI) when using active optical cable. 40G QSFP+ active optical cable (AOC) has the following categories:

40G QSFP+ to QSFP+ Active Optical Cable (AOC)

Like 40G QSFP+ to QSFP+ high-speed cable (DAC), both ends of this active optical cable (AOC) are pre-terminated with 2 QSFP+ optical transceivers, and the transmission distance can reach 100m, but the price is higher than that of high-speed cables.

40G QSFP+ to 4xSFP+ Active Optical Cable (AOC)

This active optical cable is pre-terminated with a QSFP+ optical transceiver at one end and four 10G SFP+ optical transceivers at the other end. It can also be used for 10G and 40G network connections, but the transmission distance is much longer than that of high-speed cables.

40G QSFP+ to 8xLC Active Optical Cable (AOC)

This active optical cable (AOC) provides 4 full-duplex transmission channels, the transmission rate of each channel is 10Gbps, one end is pre-terminated with QSFP+ pre-terminated, and the other end is pre-terminated with 4 duplex LC connectors, which can be used with To connect the 40G network equipment to the LC wiring system.

concluding remarks

QSFP+ high-speed cables and active optical cables are essential components in 40G networks. Using these optical components can help you save a lot of network deployment costs.