Networking models categorize and provides a structure for networking models and standards.
“Protocols are logical set of rules defining how network devices and softwares should work”.
There are two popular networking models in use today;
The Open System Interconnection (OSI) model and the TCP/IP suite.
The OSI Model
The Open System Interconnection (OSI) model was created by the International Organization for Standardization. It is a conceptual model that categorizes and standardizes different functions in a network.
The OSI model comprises of seven layers; Application, Presentation, Session, Transport, Network, Data link and Physical layers.
Explaining the OSI layers
Application Layer: The topmost layer where user applications and network services interact. It provides the interface for software to access network services like email, web browsing, and file transfer.
Presentation Layer: Responsible for data translation, encryption, and compression, ensuring that data sent by one application can be understood by another.
Session Layer: Establishes, maintains, and terminates communication sessions between applications. It also manages synchronization and checkpointing.
Transport Layer: Manages end-to-end communication, ensuring data integrity, flow control, and error correction. It includes protocols like TCP (Transmission Control Protocol) and UDP (User Datagram Protocol).
Network Layer: Focuses on routing and forwarding data packets between different networks, using logical addresses (e.g., IP addresses). Routers operate at this layer.
Data Link Layer: Responsible for addressing, error detection, and controlling access to the physical medium. It includes sublayers like MAC (Media Access Control) and LLC (Logical Link Control).
Physical Layer: This layer deals with the physical connection and transmission of raw binary data over a physical medium, such as cables or wireless signals.
TCP/IP Suite
Transmission Control Protocol/Internet Protocol (TCP/IP)
This is the conceptual model and set of communication protocols used in the internet and other networks today. It was developed by the United States Department of Defense through DARPA (Defense Advanced Research Projects Agency).
Explaining the TCP/IP Layers
Application Layer: Combining elements of the OSI’s Session, Presentation, and Application layers, this layer provides various application-specific protocols and services like HTTP (for web browsing), FTP (for file transfer), SMTP (for email), and more.
Transport Layer: Similar to the OSI’s Transport Layer, it manages end-to-end communication and data reliability. TCP and UDP are the primary protocols used here.
Internet Layer: This corresponds to the OSI’s Network Layer. It focuses on routing packets between networks using logical addresses (IP addresses). Key protocols here include IP (Internet Protocol), ICMP (Internet Control Message Protocol), and routing protocols like OSPF (Open Shortest Path First) and BGP (Border Gateway Protocol).
Network Interface Layer: Equivalent to the OSI’s Physical and Data Link layers, it handles the physical connection to the network and data link protocols for local network communication. It includes Ethernet, Wi-Fi, and ARP (Address Resolution Protocol).
Differentiating the OSI model from the TCP/IP Suite
I hope you found today’s article interesting and worth a read. You can also check out my last article on “Telecommunications”.
See you next time, bye!
