DAC or AOC: Finding the Best Cabling Solution for Modern Data Centers

As modern data centers continue to scale and adapt to the growing demands of cloud computing, AI, and virtualization, the selection of the right high-speed cabling becomes a key component in achieving optimal performance and efficiency. Especially in spine-leaf network architectures and Top-of-Rack (ToR) switch setups, choosing between Direct Attach Copper (DAC) and Active Optical Cables (AOC) can significantly impact network design and cost.

What is Direct Attach Copper (DAC)?

DAC cables are twinaxial copper cables with integrated transceivers, designed to connect directly between networking equipment such as servers and switches—without the need for separate optical modules.

Types of DAC Cables:

1️⃣ Passive DACs – No internal electronics; suitable for distances up to 7 meters.

2️⃣ Active DACs – Include signal-boosting electronics, extending the range up to 10 meters.

Typical Use Cases

• Server-to-switch connections

• Switch stacking

• Short-haul, high-density environments

Key Advantages

✅ Low Power Consumption

✅ Cost-Effective for Short Runs

✅ Simplified Cable Management

✅ Ideal for short-reach connectivity, typically within the same rack or between adjacent racks

What is an Active Optical Cable (AOC)?

AOC cables are fiber optic cables with built-in electrical-to-optical converters at each end. They transmit high-speed data using light signals over multimode fiber and are ideal for longer distances where DAC falls short.

Typical Use Cases

• Inter-rack and cross-row connections

• Spine, leaf, and core switch links

• High-speed backbone links within data centers

Key Advantages

✅ Supports longer distances (up to 100 meters)

✅ Lightweight and flexible

✅ High-speed transmission with minimal signal loss

✅ Pre-terminated and tested, reducing installation time

SUMMARY

• Choose DAC for short, intra-rack connections—simple, reliable, and cost-effective.

• Opt for AOC when longer distances and higher speeds are required across multiple racks or within data center backbones.

At Northern Link, we offer a complete range of high-performance DAC and AOC cables tailored for modern data center needs. Whether you’re building out high-density server rooms or optimizing long-range switch interconnects, we’ve got the right solution for your architecture.