UnitekFiber Solution.
UnitekFiber Solution.
What is DAC Cable

What is DAC Cable

Network cabling has changed dramatically over the years, driven by the need for higher speed fiber optic cables. DAC (Direct Attached Copper) cables are the ideal high speed solution for data center interconnections. DAC cable provides a very economical, efficient and simple connection. It is a high-speed cable with transceiver module at both ends. These direct connect cables are categorized as direct attached cables cable and AOC cables. To further understand their advantages, let's discuss in detail what direct attach copper (DAC) cables are and how to use them.

What is a Direct Attach Copper Cable?

DAC cables are made of copper, and having SFP transceiver module at the both ends that makes a direct electrical connection to the active device. The SFP transceiver modules cannot be removed from the DAC cable, so the direct attached cables are available in fixed lengths, such as 1m/2m/3m/5m/7m, etc. High-speed DAC cables are available in a variety of types: direct and breakout, passive and active. Direct DAC cables connect one port/line card to another. Breakout DAC cables connect one port to up to 4 other ports. Active DAC cable have a slightly longer transmission distance than a passive DAC cable as it uses electronics within the modules at each end to boost the signals.


Why Choose DAC Cables?

As mentioned above, DAC cables are used to directly connect ports between active devices; switches, routers, servers and storage. Their main limitation is transmission distance. There are many benefits by using DAC cables, such as low latency,high speed at short distances, durable, plug and play, flexible, allows for high density switches and lower purchase cost.

Transmission Distance

The DAC fiber optic cable can only be used if the physical distance between them is small (less than 7m). However, the maximum distance a signal can travel over a DAC cable depends on the data rate. As data rates get higher, from 10G, 40G to 100G, the distances become smaller and smaller. 100G DACs are limited to a maximum of 5m. These distance limitations mean that the most common use of DAC cables is to connect devices located in the same data rack, for example, connecting a server to a top-of-rack switch.


DAC cables are more reliable. Transceiver modules that plug directly into the device port make physical electrical contact, ensuring a secure connection. These cables are made of 26 to 28 AWG duplex copper, making them physically strong and resistant to damage during handling. These two factors mean that connections can be made quickly, reliably and economically in a variety of applications.


Using DAC fiber optic cables is always more cost effective than using two fiber optic transceivers and a fiber optic cable. The cost savings will depend on the data rate being transmitted, but it is not uncommon for it to be 2 or 3 times cheaper. Deploying a large number of DAC cables can save a lot of money when the distance allows it to be used.



DAC cable have emerged as next-generation solutions for high-density, high-speed networking applications. Features with high-speed data transfer, low-latency connectivity, cost-effective networking solutions, and simplified network setup, all of which help support the seamless operation of modern network environments.

UnitekFiber is a trusted and reputable supplier specializing in providing a wide range of fiber optic product for various networking and data communication applications. Whether you require DAC cable, fiber optic patch cord or fiber optic patch panel for data center. UnitekFiber has got you covered. For any inquiries or further information, please don't hesitate to reach out to us at sales@unitekfiber.com.

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