Direct Attach Copper (DAC) and Active Optical Cable (AOC) are the most widely used high-speed interconnection solutions in data centers, enterprise networks, and cloud computing environments. Although both are used for short-distance equipment interconnection, they differ greatly in material, performance, cost, and application scenarios. This article will help you make the best choice based on your network requirements.

What Are Passive Copper Cable (DAC) and Active Optical Cable (AOC)?
Now DAC and AOC cable are widely used, their wire material is different, but the function is the same. The customer will be confused how to choose since the function is the same. What are their advantages and disadvantages?

At the customer's request, let's talk about the advantages and disadvantages of DAC and AOC cable!

Active Optical Cable（AOC）

DAC is a copper-based direct attach cable without optical conversion, while AOC uses optical fiber for transmission. Both are plug-and-play and support hot-swappable modules such as SFP+, QSFP+, QSFP28.

Modern DAC supports up to 100Gbps (QSFP28 DAC) and is fully compatible with Cisco, Huawei, H3C, Mellanox and other brand switches.

Typical transmission distance: Passive DAC ≤ 5m; Active DAC ≤ 15m. Not suitable for long-distance or strong EMI environments.

Today’s AOC supports 100G/400G high-speed transmission, with distances up to 100m, and is completely immune to EMI/RFI interference, ideal for complex data center environments.

AOC cannot be bent excessively, and the connector is relatively fragile, requiring careful wiring.

DAC vs AOC: How to Choose Correctly?
Choose DAC if: distance ≤ 5–15m, low cost, high-density wiring, short-distance cabinet interconnection.
Choose AOC if: distance 10–100m, anti-interference required, light weight, high-speed long-distance interconnection.

ETU-LINK DAC & AOC Solutions

Last updated: April 8, 2026