The first step to building an effective cybersecurity defense is understanding what attack vectors could target a business. To know that, we can turn to analyzing interactions at each level of the OSI model – a framework for how networks communicate and operate. There are different potential threats at each level of the OSI model. By understanding this model and adapting our defenses to align with recommended actions at each layer, businesses are able to better prepare themselves for modern cyber attacks.
In this article, we’ll explore the utility of the OSI model, touch on what it is and the benefits it offers, and demonstrate how enterprises can leverage it to improve their cybersecurity defenses.
What Is the OSI Model?
The OSI model, shortened from the Open Systems Interconnection model, is a framework made up of seven distinct layers. By leveraging each of these layers, computer systems are able to communicate with one another over combat. This model has been foundational since the early 1980s, when telecommunications companies and computer businesses adopted it.
The framework is intentionally created, with each of the seven layers directly interacting with and influencing the layers that come just above or below it. For example, the Network Layer (3) will interact with the Data Link Layer (2) and the Transport Layer (4).
Here are the seven layers of the OSI model and a brief explanation of what they do in a network system:
- Layer 7, Application Layer: The application layer is the most exterior of all the layers of the OSI system. This layer is where end-users interact with a computer program and receive any data or services they request.
- Layer 6, Presentation Layer: The presentation layer takes data from the application layer, compresses it if needed, and then encrypts it. This layer facilitates the exchange of information from layers 7 to 5.
- Layer 5, Session Layer: The session layer is responsible for maintaining an open connection between the two devices that are communicating. It will manage ports and the connection to ensure data transfer is as streamlined as possible.
- Layer 4, Transport Layer: The transport layer actively breaks down data into smaller segments and then transports it to layer 3. It manages the flow of data and helps to ensure data arrives at the end of the transfer in a complete state.
- Layer 3, Network Layer: The network layer will help deliver data to specific devices on a network. It will take data from the transport layer and then send packets of data to the receiving device, finding the optimal pathway for routing the data to its end location.
- Layer 2, Data Link Layer: The data link layer performs the same tasks as the network layer but does so between devices within the same network. It will use smaller pieces of data, known as frames, to send data between devices on the network.
- Layer 1, Physical Layer: The final layer of the OSI is the physical layer, which is made up of all the physical architecture used for data transfer, like Ethernet cables. At this layer, data is transformed into a bitstream.
Together, these layers work together to allow data to flow across a network, creating a streamlined and secure system for data transfer.
Benefits of the OSI Model for Cybersecurity
The OSI model provides a framework to better understand the systems that make up the networks we use on a day-to-day basis. By offering a segmented vision of a network, cybersecurity experts can then create specific defenses at each layer of a system. Implementing security protocols at each layer will help protect against potential threat vectors that operate on that layer.
For example, DDoS attacks will commonly attack layers 3, 4, and 7, the network, transport, and application layers. Yet, a DDoS attack that focuses on the application layer is different from those that focus on layer 3 of the OSI model. By understanding how each of these attacks differs, businesses can develop precise cybersecurity architecture to defend themselves.
At each layer, enterprises can pinpoint what potential attacks they are likely to face. From there, they can create a strategy that mitigates or minimizes this threat as much as possible. A simple example would be at layer 1, the physical layer. An attack at this level would tamper with the hardware that the network relies on. Knowing this, a business could ensure that any critical infrastructure is locked away in a secure location, making it extremely difficult for an attack to occur here.
Equally, once these cybersecurity defenses are in place, teams will have an easier time troubleshooting their system, as they can pinpoint where the error or issue is on the OSI model and then find a strategy for fixing it using this enhanced context.
Leveraging the OSI Model
Developing and integrating cybersecurity solutions with the OSI model in mind is one of the most effective ways to create comprehensive security systems that keep your business as safe as possible. Rather than thinking of cybersecurity as a holistic whole, the segmented framework that the OSI model provides can allow an enterprise to create precise defenses at each layer.
By creating a diverse and layer-oriented cybersecurity strategy, businesses will be able to keep themselves safe across the entire spectrum of modern attack vectors. With effective planning, neutralizing threats like DDoS attacks and other layer-specific attacks is an accessible and achievable cybersecurity goal.
