When someone says 7 layers, what comes to mind? If you are well-read, you might think of Dante’s journey. If it is football season and you are hungry, you might be thinking about a nice bean dip. But when it comes to IT and your business, 7 layers applies to your network, and how information is sent and received. Technical people call it the OSI model. It can be a difficult topic to understand, but it’s important to note that each layer is important and needs to have its own level of protection. In this blog, Wincourse is going to try to explain this concept in an easy and digestible way, so your business can make more-informed decisions about how you manage your network.
The OSI model is a logical explanation of how different devices communicate with each other on a network. The internet is the biggest network, and every device will have some sort of point-to-point connection, but there can be gates, firewalls and other security parameters along the way.
Like onions, IT networks have many layers
We are going to start with Layer 7 because it is what most end users experience and interact with and why it’s called the Application Layer. If you’re using email, it’s represented by Outlook; if you are using a web browser, then it’s Chrome, Firefox, etc. Most of an end-user’s interactions with your internal network happen at this layer. Other side of that coin, Layer 7 is also where intruders can gain access to your network as well. If you are familiar with Denial of Service attacks or DOS, a hacker is overusing your networks resource on the Application Layer. They are breaking it down so that it becomes weak and they can infiltrate. Wincourse recommends putting a Web-App Firewall between Layers 6 and 7 to prevent those kinds of attacks – to strengthen this layer so to speak.
Layer 6 is called the Presentation Layer. And what it is doing is taking the interactions on the application layer and preparing them to be transported across the network. A good example of this is encryption and decryption of your secure information before it goes across a public network. This also where the operating system exists, so it’s here that we make sure our applications are compatible and will present correctly to the end-user.
Here’s where things start to get electric and a little interesting. Layer 5 is what is called the Session Layer. This layer establishes the communication guidelines for 2 points on the network when they need to talk to each other. Guidelines like how long a request should take to ping a server before it shuts off. That amount of time and the rules those two machines are following is called the session.
Layer 4 is the Transport Layer. You can think about it like the post office. It’s not the one packing or shipping stuff, that’s the end user. But, it is making the rules about when things are delivered, how many packages are going out at a time, and will tell you when a package cannot be delivered. Most firewalls exist at this layer because you are still at a software level, moving forward we start to get into actual physical connections.
Starting with the Network Layer at Layer 3. These are your IP addresses, and your router functionality exists here. If you are delivering an application from North Carolina to an end-user in California, there are a lot of connections that information has to pass through. The network layer is determining what route to take, whether it is the most effective one, the safest one, or a combination of the two.
Hope this isn’t getting too technical, but Layer 2 is called the Data Link Layer. This is making sure any two nodes connected to the switch can talk to each other. Switches are what connect all routers and networks together. Not to be confused with the Nintendo console.
And finally we have the Physical Layer. This can be represented by the actual cables and wiring connecting points to points. You don’t have to be a network expert to troubleshoot this sometimes, just make sure everything is plugged in correctly.
Now if you need help troubleshooting network issues, and cannot quite seem to figure out why, you can always get a health check from a Wincourse Engineer. It may be a simple fix, but as you can see there are a lot of layers to networking problems. And it is a good to have a partner like Wincourse to better explain what the underlying issue might be with your network performance. We make it less like Dante’s Inferno, and more like an award-winning 7-layer dip on Super Bowl Sunday.