Backbone Cabling vs Horizontal Cabling

Types of Network Cabling Designs

Networking designs for data centers and other facilities with very high bandwidth usage is not a simple task. In reality, there are many different networks all nested on top of each other, and keeping track can prove burdensome.

One way to help distinguish these different nests of networks is to define them by their function. That’s why you will often see mentions of backbone and horizontal networking. What do these terms mean, and what kinds of cables are appropriate for each?

What Is Backbone Cabling?

Backbone cabling, also commonly called vertical cabling, is infrastructure cabling that connects various networking rooms in a facility. As an example, backbone cabling would be used to connect two equipment rooms to each other, or it would form the primary connections between an equipment room and a telecommunication room.

As the name suggests, this type of cabling forms the backbone of the facility’s connections. That means that backbone cabling tends to operate in very high bandwidth ranges, and it tends to be one of the more expensive portions of cabling in a networking facility.

What Kinds of Cables Are Used for Backbone Connections?

To keep up with bandwidth needs, a number of different cabling types can be used. In backbone infrastructure, you will often see unshielded twisted-pair (UTP) cables, fiber optics, coaxial cables, and shielded twisted-pair (STP) cables.

Considering the speed demands on these cables, they typically do not run for more than 30 meters before terminating. Because of this, nodes on a backbone network need to be strategically placed. If they aren’t close enough, supplying fast enough cables at longer distances can push cable costs extremely high.

What Is Horizontal Cabling?

Horizontal cabling is the facility infrastructure that connects telecommunications rooms to endpoints. With this cabling, a single telecommunications room can quarterback networking for a large number of endpoint devices, making this another core portion of the infrastructure.

Because the horizontal cables are connecting endpoint devices, the bandwidth demands for each individual cable are much lower. Horizontal cabling will frequently run up to 90 meters in length along a star topology, and the specific cables used are often less expensive when compared to backbone cabling.

What Cables Are Typically Used?

Horizontal cabling choices have a lot more flexibility, and because of that, they are usually chosen along cost optimization rather than pure performance.

For horizontal cabling, you will often see Cat5e Ethernet (or more advanced Ethernet options as needed). When necessary, 62.3/125-micron or 50/125-micron fiber optic cables are deployed.

While these are the most common cabling choices, ultimately, horizontal cables are derived from whatever supplies enough performance at the lowest cost.

What Are the Primary Differences Between Backbone and Horizontal Cabling?

The purpose of each type of cabling drives all of the differences between them. Technically, you could use the exact same cables for both backbone and horizontal design, but it would not be very efficient.

Backbone cabling moves very large amounts of data across each cable. Horizontal cabling moves smaller amounts of data per cable, but it connects to many more nodes. This means that backbone cabling has stiffer performance demands while horizontal cabling will ultimately run for much longer distances.

In most cases, backbone cabling must be chosen along high-performance demands, and it is run as short as possible because of the cabling costs. Horizontal cables are often chosen for how cheap they are, and it’s often more cost-effective to have longer runs of cheaper cables than the other way around.

Ultimately, the purpose dictates the cables, but when you understand the key differences among cabling applications, it’s easier to see where you have freedom in your design choices. With that freedom, you can look for optimizations and design a network that functions properly while saving money.

Additional Learning Center Resources