What is a Campus LAN Switch & How are They Used?

Quick Guide to Campus LAN Switches

Designing a campus network is not a small task. Just browsing campus LAN switches can feel like a lot of work. There is so much variety that it becomes difficult to pick which devices are really right for your network.

The good news is that it doesn't have to be so hard. When you think about campus LAN switches in terms of where they fit in the greater network, it’s easier to filter search results and find the right product.

In order to do that, a quick guide can help a lot. So, here’s a quick rundown of campus LAN switches and modern campus network design theory.

What Is a Campus LAN Switch?

When building a network for an entire campus, one of the primary concerns is speed. End users need good effective connection speeds, and in order to provide that, the network has to be optimized for the end user.

The key to that is minimizing the route between the end user and the greater internet. In order to do this, you want a network that doesn’t require long chains of connections.

The three-tier model solves this by allowing endpoint devices to get out of the LAN in three jumps or fewer. The primary jumps will connect to the access layer. From there, LAN switches communicate with the distribution layer. Finally, the core layer is the last stop before getting beyond the LAN and to the rest of the internet.

So, in order to understand the three-tier model, it helps to break down each layer by its general function.

Understanding the Three-Tier Model

With so much power and ability, it’s easy to see why the 3850 shows up in a lot of applications. The bulk of those applications exists in the enterprise space. The 3850 is great as a distribution switch on campuses. It can provide Layer-3 networking in smaller systems.

You’ll find 3850 switches implemented for remote monitoring, forming the backbone of healthcare networks and generally doing the heavy lifting for large, robust networks.

Core Layer

The core layer is the top layer with the fewest number of switches and the highest bandwidth. The whole campus network runs through this layer before connecting to internet devices on the outside.

The core layer is responsible for providing high speeds and throughput for the layers below it. Because of this, the fastest switches and nodes are placed here. The outer layer is where you will find 10G and faster switches — enabling these devices to handle the pure scale of traffic coming through.

Distribution Layer

The distribution layer is arguably the most important. While the core layer handles large amounts of raw data and communication, the distribution layer is more of the brains of the operation. This is where you put your network services, so distribution layer campus LAN switches need to serve more specific functions.

Switches in this layer usually operate with Layer 3 functionality. Most routing protocols happen in the distribution layer, and this is where you would typically build your routing protocols. The distribution layer also handles DHCP services.

Distribution layer switches don’t need as much raw speed as core layer switches, but they still can’t be slow, as you’ll have multiple nodes attached to each distribution layer switch.

What matters most is that these switches can provide the services needed to run the campus network.

Access Layer

The access layer is the last in the three-tier model. Access layer switches connect directly to endpoint devices, like laptops and smartphones. This is typically Layer 2 switching. The access layer is where switches take care of MAC address mapping, and it’s where a lot of specific network management happens. For instance, endpoint devices are assigned ports at the access layer.

As you might imagine, access layer switches don’t need as much raw speed or as many special features as switches designed for the other two layers. Additionally, most campus networks will have more switches in the access layer than any other, so this is where affordability matters most in your hardware selection.

Bottomline on Campus LAN Switches

When you think about campus LAN switches in terms of these three layers, it’s easier to filter the results for a switch that is appropriate for the specific job it will perform. Matching specifications and features to the three separate layers is a lot easier, and anticipating this kind of design can help you shop for switches that are affordable, scalable, and capable in the exact ways you need them to be.

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