What is an Access Point?

Quick Definition: An access point is the part of the wireless network that broadcasts the signal and allows clients to access the network.

Ever wonder how your phone magically connects to Wi-Fi when you walk into a coffee shop or office? That’s thanks to an access point (AP). No, it’s not a router (even though people love to mix them up), and no, it doesn’t summon the internet from the void. 

What it does is broadcast a wireless signal, letting your devices connect to the network without tripping over a mess of Ethernet cables. 

Access points are everywhere—hotels, airports, schools, even that one friend’s house who actually knows how to set up good Wi-Fi. But not all APs are created equal, so let’s break down what they do, how they work, and why they matter.

What is an Access Point?

Access point (or AP) is a seemingly ambiguous word that can be used in several ways. However, in the world of IT and computer networking, it has a very specific meaning. Access points, sometimes called wireless access points or even (egregiously and incorrectly) routers by consumers, do one essential thing: they broadcast a wireless network.

Why are APs Important? 

Access points, hereafter referred to as APs, are all around us. At this point in modernity, it’s actually strange not to have Wi-Fi somewhere. As mentioned above, APs are the point at which the whole network becomes available to you. More precisely, an AP is responsible for actually generating the signal that you receive on your phone. 

There are various types, makes, and models of APs, but the important thing is that they’re the foundation of your wireless network. It handles the Layer 1, 2, and sometimes even 3 processing and traffic that you and your guests generate and keeps you untethered from cables as you move about. 

If the layers aren’t familiar to you, I suggest checking out CBT Nuggets Network+ Training for a refresher.

APs can be viewed as a point for ingress or access into the system for your phone, computer, or other device. Importantly, they behave differently than a switch or a router. They have some similarities but carry many, many more possible clients and restrictions. 

They do not natively direct traffic across subnets, nor do they send it across the internet on their own. APs allow access to the network, manage the wireless transmissions, and communicate primarily on Layer 2 with their own unique types of traffic.

Types of Access Points

Access points come in two main flavors: controller-based and standalone. These differ primarily on the backend, though they do offer very different experiences. There's also a third option, which we'll discuss after we cover the first two. 

Standalone

Standalone access points, sometimes called independent access points, are the ones consumers usually interact with in the home. These APs are single and typically integrate a router and/or switch. They generate a signal and a number of SSIDs, but most notably, they do not connect or communicate with others. They are incapable of performing the other functions of the more advanced controller-based access points. 

Standalone access points are most common in the consumer market but may also be found in SMBs. Interestingly, a midpoint is emerging in the market, particularly from Aruba. 

These access points are mostly standalone but will occasionally communicate with each other over the network and via Bluetooth, depending on the model. They’re still not a fully unified network, but they do provide some more advanced features. They, like most, are provisioned and set up individually and don’t “Call home” to a controller but will roam somewhat efficiently. They are capable of doing something that most are not, allowing a smoother experience than the “true” standalone.

Controller Based Access Points and Beyond

Most people will encounter controller-based access points at work or in larger venues. These are the products of a larger design and work together in a semblance of harmony. These APs are all managed by the aptly named wireless LAN controller, which serves to coordinate them. 

The controller unifies them under a single SSID and mediates the settings on the APs. Standalone APs, even when set up to have identical SSIDs, cannot mediate things like roaming. This causes the client to lose connection as they move from place to place; they don’t share a back-end, or what we call a distribution system. This means that every roam is a “hard” roam. 

Think about being on a video call while walking, and it freezes and buffers every 50 feet. The controller also prevents them from getting in each other’s way, allowing the admin to coordinate channels and power according to the wireless network’s design (if that interests you, check out CBT Nuggets Wireless Design Professional training). When channels clash, performance suffers—generally, this means a slower speed or sometimes even outright dropped connections. 

A controller is generally a physical presence on the network, though it can also be a virtual appliance. Both Ubiquiti and Aruba have popular virtual platforms that can run on a normal computer. These APs can also be “lightweight,” meaning that the functions they offer are significantly pared down or non-functional if they are not attached to a controller.

The Third Option: Cloud Controllers

A relatively new option for APs is to connect to the cloud, which enables a relatively lightweight solution without having an expensive and power-hungry controller onsite. These APs reach out directly over the internet for configurations such as SSID, security settings, power, and channel. 

Cloud-based APs usually offer unique amenities such as Map Placements, offloading authentication to a cloud or native service, and anywhere-access management. These are much easier to administer but may create their own security challenges. Cloud-based APs typically also communicate among themselves both on and off the wireless network itself; MIST and Ubiquiti both have this model. They primarily 'talk' to each other via Bluetooth, sharing channel information and management traffic.

These and controller-based APs also do something standalone cannot: They sense and adjust based on the existing RF energy in the environment. Left to their own 'devices,' they typically adjust to provide better service, managing power and channels to send out enough energy without overwhelming the network. This is also referred to as RRM, which is exclusively a property of Cloud and Controller-based APs. Standalone APs cannot tell the difference between “friend and foe,” so to speak.

Final Thoughts  

Access points are the cornerstone of a wireless network. Well designed and deployed, the proper architecture can make or break a good wireless service. Some are well suited for the home, cheap, and easy to use. 

Others are more involved and require a skilled hand! Be careful and use this information when you select your next wireless device. The differences between standalone, controller-based, and cloud APs will make a massive difference to your and your client’s experience.

For more information on APs and SSIDs, check out CBT Nuggets CWNA Training.