Cyber security for Beginners: Part 10
Hey everyone! After a long break, I’m back to discuss the topics that a beginner would need to understand before they can get into the field of Cybersecurity. In this blog, we are going to discuss yet another reference model used for networking: TCP/IP model.
The TCP/IP model is a reference model used in networking to enable communication between dissimilar systems in a network. Like the OSI model, this, too, is a conceptual model. This means that the layers of this model doesn’t necessary exist in a system as any physical or software based components. Rather, they are used for understanding how communication takes place in a computer network and how data is transmitted from an application on one computer to an application on another computer.
TCP/IP reference model was designed by the Department of Defense (DoD) in the 1960s for facilitating communication in computer networks. TCP/IP can be considered as a more compact version of the OSI model, where the 7 layer OSI model has been reduced to a 4 layer design. The comparison between the 4 layers of the TCP/IP model with reference to the layers of the OSI model are shown below:
The 4 layers of the TCP/IP reference model are:
- Application layer
- Transport layer
- Internet layer
- Network Access layer
We’ll discuss the functionalities of each of these layers in the coming sections.
Application Layer
The application layer of the TCP/IP model comprises the functions of the top 3 layers of the OSI model, namely; Application layer, Presentation Layer, Session layer. The Application layer in TCP/IP model takes care of providing applications with access to network services, manages the session information during the communication between 2 applications, and also takes care of the presentation of the data (encoding, compressing, decoding, decompressing, etc.). The Application layer also provides the users of a networked device access to the underlying networking facilities. Some of the protocols that exist at this layer include: HTTP/S, FTP, SNMP, SSH, and many more.
Transport Layer
The functions of the transport layer in TCP/IP model is same as that of the OSI reference model. This layer is responsible for end-to-end and error-free transmission of data. The 2 main protocols that exist at this layer are: TCP & UDP. I’m not getting into the details about these 2 protocols because we’ve already discussed them in earlier blogs.
Internet Layer
The internet layer is nothing but the Network layer of the OSI model. Both these layers are responsible for providing Logical addressing, routing, and forwarding functionalities. This layer is responsible for the transmission of packets from a source device to a destination device. One of the primary protocols of this layer is the IP protocol, which provides connectionless delivery of datagrams across a network. Some of the protocols that exist at this layer are: ICMP, ARP, IGMP etc.
Network Access Layer
The Network access layer is the combination of the Data Link and Physical layers in the OSI model. This layer is also known as the Host-to-Network layer. This layer is responsible for physical addressing, error detection and correction, and the physical transmission of data in the form of bits.
So that’s it for this blog and make sure to check out the links attached below for learning more about the TCP/IP reference model if you are interested. Until then , sayonara!
Additional Learning:
TCP/IP Reference model:
