How Many 100G QSFP28 Cable Types Do You Know?

Author Yana

Date 10/18/2024

This article provides an overview of the different QSFP28 100G cable types, including 100G DAC and 100G AOC, and their uses in data centers and high-performance computing.

100G QSFP28 cables are now a key component in data centers and high-performance computing environments. How many 100G QSFP28 cable types are there? They not only cover 100G QSFP28 DAC (Direct Attach Copper) and 100G QSFP28 AOC (Active Optical Cable) but also include a wide range of breakout cables to meet different network connectivity needs. This article will take you through the features of these QSFP28 100G cable types and their application scenarios to help you make the best choice when building or upgrading your network.

100G QSFP28 Transceivers VS QSFP28 Cables, What's the Difference?

100G QSFP28 DAC, AOC is a cable assembly with fixed connectors at both ends. The connector used is the same as the interface of the 100G optical module, but compared to the optical module, the 100G DAC and AOC do not need to be used with fiber optic cables, and the connector of the 100G DAC does not have expensive optical lasers, which greatly saves costs and becomes a cost-effective and high-speed data communication solution that replaces 100G optical modules.

100G DAC (Direct Attach Cable) Types

100G DACs can be categorized into active 100G DACs and passive 100G DACs, while passive 100G DACs can be categorized into 100G QSFP28 to 100G QSFP28 DACs, 100G QSFP28 to 4× 25G SFP28 DACs, 100G QSFP28 to 2x 50G QSFP28 DACs, and these three passive DACs are described in detail below.

100G QSFP28 to 100G QSFP28 DAC

100G QSFP28 to 100G QSFP28 DAC is one of the most common types of DACs, used for connecting two 100G network devices, such as switches and servers. These cables support high-speed data transmission and are commonly used in short-distance interconnect scenarios in data centers for top-of-rack (ToR) interconnections between 100G ToR switches and servers, or stacking of 100GbE switches.

100G DAC QSFP28 Breakout Cables

100G bandwidth into multiple lower-rate signaling channels to meet the bandwidth allocation needs in a variety of application scenarios. There are two common types of 100G QSFP28 break cables: One splits the 100G bandwidth into four 25G channels, and the other splits the 100G bandwidth into two 50G channels.

100G QSFP28 to 4× 25G SFP28 DAC Breakout Cables

100G QSFP28 to 4× 25G SFP28 breakout cables has a 100G QSFP28 on one end and four 25G SFP28 on the other end. It is easy to install and has a solid structure. This breakout DAC provides four parallel bidirectional channels, each operating at up to 25Gps, and can be used for interconnection between 100G and 25G devices. It supports a distance range of 1 meter to 5 meters and is widely used in data center or supercomputing center system scenarios.

100G QSFP28 to 2x 50G QSFP28 DAC Breakout Cables

100G QSFP28 to 2x 50G QSFP28 DAC splits the 100G into two 50G channels, enabling efficient short-distance connectivity from a 100G network device to two 50G devices. It is suitable for scenarios such as data centers that require flexible bandwidth allocation. It has a lower cost and power consumption than optical modules and is also suitable for short-distance applications.

100G AOC (Active Optical Cable) Types

With the rapid development of big data and cloud computing, the demand for data transmission is increasing daily. 100G AOC, as the transmission carrier for short-distance data in 100G data centers, is mainly used in data center server rooms, high-performance computing, storage area networks, etc. It has the advantages of long transmission distance, fast transmission rate, and ease of use. Below are several common 100G AOC product types.

100G QSFP28 to QSFP28 AOC

100G QSFP28 AOC consists of multimode optical fiber equipped with QSFP28 form factor modules at both ends. This cable is lightweight, has a small bending radius, and is easy to install. It is suitable for high-density architecture. QSFP28 to QSFP28 100G AOC is suitable for short-distance, multi-channel data communication applications in various positions within data centers, such as ToR (Top of Rack), EoR (End of Rack), and MoR (Middle of Rack).

100G AOC QSFP28 Breakout Cables

100G QSFP28 to 4x 25G SFP28 AOC Breakout Cables

This 100Gb breakout cable overcomes the bandwidth limitations of traditional copper cables and splits a 100G QSFP28 into four 25G SFP28. It provides IT professionals with a cost-effective combination of 100G QSFP28 and 25G SFP28 interconnect solutions and is widely used in server cluster connections within data centers.

100G QSFP28 to 2x 50G QSFP28 AOC Breakout Cables

100G QSFP28 to 2x 50G QSFP28 AOC split cable divides a 100G port into two 50G QSFP28 ports, which is suitable for network scenarios that require medium bandwidth. This solution is very suitable for gradual expansion applications in data centers. It can be connected through 50G QSFP28 first and then upgraded to full 100G bandwidth when needed in the future, providing network flexibility.

FAQs about QSFP28 Active Optical Cable and Direct Attach Copper Cables

Q: What are the advantages of QSFP28 cables?

A: The advantages of 100G QSFP28 cables include high-speed transmission, low power consumption, and compatibility with various network devices. They also come to various lengths to meet different network needs.

Q: Can QSFP28 100G cables be used for 40G?

A: Yes, QSFP28 100G cables can be used for 40G, but not vice versa.

Q: Can 100G AOC and DAC be mixed?

A: You can use AOC and DAC simultaneously. However, each connectivity solution should be properly deployed based on transmission distance and performance requirements.

Q: QSFP28 AOC vs QSFP28 DAC, what’s the difference in power consumption?

A: The power consumption of QSFP28 AOC is slightly higher than DAC.

Conclusion

In summary, 100G QSFP28 cables are important in high-performance computing environments and data centers, and they are of multiple types to meet different network connection needs. If you want to know more about QSFP28 100G cables, you can contact QSFPTEK's technical team at [email protected].