What is AOC and DAC?

AOC is the abbreviation of Active Optical Cables, which is called Active Optical Cables in Chinese. AOC active optical is to encapsulate two optical modules and cable together. Because the medium of transmission in the middle is optical cable, AOC optical module, which contains laser devices, has a higher price for DAC. However, its optical aperture is not exposed, it has high reliability, and its working distance can be customized for a long distance of less than 100 meters.

Active AOC cable is actually a jumper with optical modules. AOC is generally short in length, up to several hundred meters, the biggest feature is that optical modules and optical fibers are integrated, can’t be separated. The advantage is that the overall cost is relatively low, because the optical fiber is fixed in the module, and some optical devices are less used in the manufacturing process. AOC active optical cable is suitable for short-distance application scenarios, not for long-distance transmission scenarios, which is obvious, optical cable can’t be that long. AOC active optical cable is widely used in IDC data center computer room.

AOC has low environmental requirements, no cleaning problem of fiber optic connectors, cost optimization, no DDM function. Disadvantage: It is not flexible to configure the distance. It is necessary to confirm the transmission distance in advance before leaving the factory.

40G high-speed cable (DAC) is a kind of high-speed interconnection solution, which can realize 40Gbps data transmission and has both ends equipped with optical transceivers. 40G high-speed cable can be divided into three types: 40G QSFP + QSFP + DAC, 40GQSFP + 4*SFP + DAC, 40GQSFP + 4XFP + DAC, which are more commonly used in practice. 40G QSFP +to QSFP+DAC is composed of two 40G QSFP +optical transceivers and copper core wires. The existing 40G QSFP +ports to 40G QSFP +ports can be interconnected by using this high-speed cable. Generally, the distance between 40G QSFP +ports and 40G QSFP+ ports can only be within 7m.40G QSFP 4*SFP+DAC is composed of a 40G QSFP+ optical transceiver, copper core wires and four 10G SFP+ optical transceivers. It is mainly used to realize the interconnection between 40G and 10G devices (NIC/HBA/CNA, switch devices and servers), generally only within 7m distance. 40G QSFP+ 4XFP DAC is composed of a 40G QSFP+ optical transceiver, copper core wires and four 10G XFP optical transceivers. Because XFP optical transceiver does not have the standard of DAC copper cable, the signal compensated by the equipment is low, the loss of the cable itself is very large, and it can only transmit in short distance, usually within 2 m distance. Therefore, this kind of high-speed cable can be used to realize the interconnection between the existing 40G QSFP port and four XFP ports.

40G QSFP module is a four-channel small pluggable optical module with a transmission rate of 40Gbps. It can realize the interconnection between network devices (such as switches, routers, media converters, etc.) and optical cables or copper cables. Its structure is more compact than CFP optical module, so it is more suitable for applications with high port density. 40G QSFP + optical module can be divided into 40GBASE-SR4 optical module, 40GBASE-LR4 optical module, 40GBASE-ER4 optical module and 40GLR4 PSM optical module.

What is DAC?
DAC is the abbreviation of direct cable. The connector of DAC is the same as the module. However, compared with the module, DAC connector does not have high-priced lasers and other electronic chips, so it saves a lot of costs in short-distance transmission, and replaces the module with a lower cost, bringing higher benefits for network solutions. What is the structure of DAC? 

DAC consists of silver coated conductors and foam insulated core wires, and shields are used to form high-speed cables. DAC has excellent attenuation performance, low delay and anti-interference. High frequency broadband transmission can also be realized. What are the advantages of DAC?
A. High performance: for short-distance data center wiring, using a variety of integrated solutions exchange capabilities.
B. Energy-saving and environmental protection: The inner material of high-speed cable is copper, which has natural cooling effect and saves energy.
C. Low power consumption: the power consumption of passive optical cables is 0, and that of active optical cables is about 440 MW.
D. Low Cost: Copper is much cheaper than optical fibers.