What Do You Need to Know About Breakout Mode on FS Switches?

Posted on Mar 20, 2024 by

In the world of data centers and high-speed networking, the term "breakout mode" frequently surfaces, often in conversations regarding switch capabilities and port configurations. This feature is particularly significant as networks demand more flexibility and higher bandwidth capabilities. This article delves deep into the concept of breakout mode, its significance, and how FS switches are harnessing this technology to provide state-of-the-art networking solutions to the enterprise market.

What Is Breakout Mode?

Breakout mode is a configuration that leverages a high-bandwidth interface and "breaks it out" into multiple lower-bandwidth interfaces. Typically, this configuration applies to Ethernet switches where a high-speed port, such as a 40G QSFP+ or a 100G QSFP28, is divided into multiple smaller connections, like 4x10G or 4x25G. This subdivision allows network engineers to connect to devices that require lower bandwidth connections while still efficiently using the switch port resources.


To configure breakout mode, a network administrator would typically use the switch's software interface to specify how the physical port should be divided. This may involve using special breakout cables or transceivers, such as DAC (Direct Attach Cable) and AOC (Active Optical Cable), which physically split a single port into multiple connectors, which can then be plugged into other network devices. Choosing the right breakout solution depends on the specific network needs, distance and required bandwidth. By utilizing DACs, network administrators can establish cost-effective connections for short reaches within the data center, while AOCs can be employed for longer distance transmission that requires high bandwidth and lower signal attenuation. These breakout options extend the versatility of FS switches, allowing a higher-density port to be split into multiple interfaces, giving the flexibility to connect with various speeds ranging from 10G, 25G, to 40G, or 100G as needed.

Advantages of Using Breakout Mode

Breakout mode is an invaluable feature for data centers transitioning from 10G/25G to 40G/100G networks, as it provides backward compatibility and a smoother migration path.

  • Flexibility: Breakout mode allows network architects to cater to varied connectivity needs within their network. For instance, they can connect switches with 10Gbps ports to a 40Gbps switch without needing to upgrade all equipment to support 40Gbps interfaces.

  • Improved Port Utilization: Instead of leaving a high-speed port underutilized because there aren't enough devices that operate at that speed, breakout mode allows the connection of more devices at lower speeds, thereby utilizing the port's capacity more effectively.

  • Scalability: As network requirements grow or evolve, breakout mode can help accommodate new devices and configurations without the need for immediate infrastructure overhauls. This helps in growing the network in a cost-effective manner.

  • Cost Savings: By efficiently using available port speeds and reducing the need for additional switches or upgrades, breakout mode can lead to significant cost savings.

  • Simplified Infrastructure: Networks can be simplified by avoiding unnecessary uplink ports and by limiting the number of switches in aggregation layers, thanks to the increased port density enabled by breakout mode.

  • Decreased Power and Cooling Requirements: More efficient utilization of switch ports leads to reduced need for additional hardware, which in turn can reduce the power consumption and cooling requirements in a data center.

Application Scenarios

The Breakout mode on switches has several specific applications tailored to the needs of modern data centers, campus networks, and cloud infrastructure.

For instance, in a data center, breakout mode is highly advantageous in scenarios where top-of-rack (ToR) switches with high-speed ports need to connect to access switches or servers that have lower-speed interfaces. With breakout mode, you can maximize port usage and eliminate the need for additional hardware, thereby reducing capital expenditure and simplifying the network design.


In addition to providing an efficient migration path, breakout mode supports high-density port layouts within racks, making it ideal for data centers with limited space. It effectively increases the number of available ports without physically adding more switches. At the same time, it helps simplify cable management, reduces the potential for cable-related errors, and also decreases costs associated with excessive cabling.

It also allows for more granular bandwidth management, catering to the requirements of different network segments. Such precise control helps optimize traffic flow and can lead to improved network performance.

Which FS Switches Support Breakout Mode

FS.com, a recognized player in providing integrated networking solutions, provides a variety of switches that are breakout mode-ready. For instance, the FS S5850, S8550 and S8050 series are equipped with high-speed QSFP28 ports that can be configured in breakout mode. These switches not only provide diverse port speeds but also allow network engineers to tailor the switch ports to various roles within the network topology. Here is the list of FS enterprise switches that support 100G to 25G breakouts.

Switch Series
S5850 series
24-Port Ethernet L3 Switch, 24x 10/100/1000M/2.5G/5G/10GBASE-T, 2x 40Gb QSFP+/100Gb QSFP28
24-Port Ethernet L3 Switch, 24x 10/100/1000M/2.5G/5G/10GBASE-T PoE++, 2x 40Gb QSFP+/100Gb QSFP28
24-Port Ethernet L3 Switch, 24x 1/10G SFP+, 2x 40Gb QSFP+/100Gb QSFP28
48-Port Ethernet L3 Switch, 48x 10Gb SFP+, 8x 40Gb QSFP+/100Gb QSFP28
S8550 series
8-Port Ethernet L3 Switch, 6 x 40Gb QSFP+, 2 x 100G QSFP28
32-Port Ethernet L3 Switch, 16 x 100Gb QSFP28, 16 x 40Gb QSFP+/100Gb QSFP28
16-Port Ethernet L3 Switch, 16 x 40Gb QSFP+, 8 x 40Gb QSFP+/100Gb QSFP28
S8050 series
20-Port Ethernet L3 Switch,4x 10Gb SFP+, 20x 40Gb QSFP+, 4x 40Gb QSFP+/100Gb QSFP28
QSFP+ can be used for 40G or 4x 10G connections. QSFP28 can be used for 40G/100G or 4x10G/4x25G connections.

It's important to consult FS product documents or contact their technical support to identify which specific switch models support breakout mode and the available configurations. This information is vital for ensuring compatibility with the intended network design and for the successful implementation of breakout mode.



Breakout mode on FS switches is a compelling feature that can introduce significant flexibility and efficiency within a network. Through its ability to break high-bandwidth ports into multiple lower-speed interfaces, it offers backward compatibility and future-proofs your network investment. And FS provides the physical connection options needed for breakout mode, including DAC and AOC, ensuring that connections can be customized according to various distance and bandwidth requirements, thereby optimizing the architecture of the network infrastructure.

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