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Differences Between 100G QSFP28 AOC And 100G QSFP28 DAC

We know that 100G QSFP28 active optical cable AOC and 100G high-speed copper cable DAC both play the role of data transmission. However, there are differences between 100G QSFP28 active optical cable AOC and 100G high-speed copper cable DAC. Next, the difference between 100G QSFP28 active optical cable AOC and 100G high-speed copper cable DAC will be explained in detail.

Meaning

1. What is 100G QSFP28 active optical cable AOC?
100G AOC active optical cable refers to the communication cable that uses external energy to convert electrical signals into optical signals or optical signals into electrical signals. Optical transceivers at both ends of the optical cable provide optical conversion and optical transmission functions, and the transmission rate reaches 100 GB/s.

2. What is a 100G high-speed copper DAC?
100G high-speed copper cable DAC adopts silver plated conductor and foam insulated core wire, which has excellent attenuation performance and low delay performance, accurate signal transmission, and can improve transmission speed. It is a short distance connection solution to replace optical modules. Its price is much lower than that of similar optical modules, so it is widely welcomed in short distance connection applications.

Meaning

1. What is 100G QSFP28 active optical cable AOC?
100G AOC active optical cable refers to the communication cable that uses external energy to convert electrical signals into optical signals or optical signals into electrical signals. Optical transceivers at both ends of the optical cable provide optical conversion and optical transmission functions, and the transmission rate reaches 100 GB/s.

2. What is a 100G high-speed copper DAC?
100G high-speed copper cable DAC adopts silver plated conductor and foam insulated core wire, which has excellent attenuation performance and low delay performance, accurate signal transmission, and can improve transmission speed. It is a short distance connection solution to replace optical modules. Its price is much lower than that of similar optical modules, so it is widely welcomed in short distance connection applications.

Product Structure

1. AOC structure of 100G active optical cable
The active optical cable is composed of two optical fiber transceivers and one optical cable jumper. It is composed of optical fiber transceivers at both ends and different optical fiber types OM3 and OM4 multimode optical fiber.

2. 100G high-speed copper DAC structure
High-speed copper cables can be divided into passive high-speed copper cables and active high-speed copper cables. Active high-speed copper cable has one more driver chip than passive high-speed copper cable. The "optical modules" at both ends of the high-speed copper DAC are not real optical modules. They have no components and can only transmit electrical signals. Therefore, the high-speed copper DAC is cheaper than other ordinary optical devices. Even if the same port is used as the fiber module interface, high-speed copper cable can save cost and reduce power consumption in short-distance applications. This is why people choose high-speed copper cables. High-speed copper DAC, connected to switches or servers at both ends, allows short-distance transmission.

Classification

1. AOC classification of 100G active optical cable
There are two types of 100G AOC: 100G QSFP28 active optical cable AOC and 100G QSFP28 to 4x25G SFP28 active optical cable. There are optical module receivers at both ends of the electronics. Allow one-to-one transmission. The latter has 100G QSFP28 connectors at one end and four 25G SFP28 connectors at the other end, providing 100G data transmission for customers.

2. 100G high-speed copper DAC classification
There are two types of 100G high-speed copper DAC: 100G QSFP28 DAC direct-attached copper and 100G QSFP28 to 25G SFP28 DAC direct-attached copper. There are optical module receivers at both ends of the electronics. Allow one-to-one transmission. The latter has 100G QSFP28 connectors at one end and four 25G SFP28 connectors at the other end, providing 100G data transmission for customers.

FAQs About 100G DAC/AOC Cables

Q: What is the difference between 100G DAC and AOC?
A: 100G DAC is composed of Twinax copper cables with connectors on both ends, while 100G AOC is MMF cable with SFP connectos on both ends. There are several differences between these two cables. In general, 100G DAC consumes less power and is more cost-effective than 100G AOC. By contrast, 100G AOC supports higher performance in transmission distance and is also more suitable for data center deployment. For more information on the difference between DAC and AOC cables, please read Data Center Cabling Solution: DAC Cables vs AOC Cables.

Q: What is the structure of 100G AOC?
A: 100G AOC mainly consists of two optical modules and an optical cable jumper. The transceivers at both ends are composed of different lengths of OM3 or OM4 multimode fiber.

Q: Can 100G QSFP28 cables be used for 40G?
A: Yes, QSFP28 cables can be used for 40G, but not vice versa. There is a rule about mixing optical transceivers at a different speed: both ends of the two modules have to match and the form factor needs to match as well. Additionally, port speed needs to be equal or greater than the optic used.

Q: What does the breakout mode of QSFP28 cable mean?
A: Breakout mode refers to running a 100G port as 4 separate channels of 25G or 2 separate channels of 50G. When breaking out a single 100G port to 4x 25G or 2x 50G links, the Forward Error Correction (FEC) mode on both ends of the link must be the same to ensure link-up.

Q: Can customers use third-party QSFP28 Cable?
A: Yes, third-party 100G passive copper cables can be used but all the cables are required to comply with the associated IEEE specifications, as well as SFF-8636 management interface / EEPROM specifications to allow them to be correctly identified and recognized by the switch/router.


Post time: Mar-06-2023