OSI model vs TCP/IP model – What’s the difference?

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OSI model vs TCP/IP model

We’re covering the difference in the OSI model vs TCP/IP model topic because always trying to help you know your networks better. Similarly, after writing about how to make or draw a network topology diagram, we thought it’d be helpful to create a more in-depth post about the OSI model vs TCP IP model. 

Given that, Domotz network monitoring software includes network topology diagrams, it’s relevant to understand how these fit into the OSI model. To further elaborate, our topology maps display elements from; Layer 1 (links and physical devices), Layer 2 (MAC addresses), and Layer 3 (IP addresses).

So with that, let’s dive into the OSI model, comparing it with the TCP/IP model. 

Jump ahead to your preferred sections and get answers to frequently asked questions.

OSI model vs TCP/IP model – What’s the difference?

The Open Source Interconnect (OSI) model is a generic protocol model with 7 layers. It’s used to characterize network communications. Ultimately, this is important because standard protocols enable the transmission of data packets and exchanges between various networks.

In other words, these regulations are known as protocols. Similarly, one of the most extensively used protocols is the Transmission Control Protocol (TCP) Internet Protocol (IP).

OSI Model Overview

To start off, the OSI (Open System Interconnection) standard was created in the 1980s. Ultimately. it’s a type of network communication conceptual model. The OSI model has seven levels, each related to the others. Each layer of the OSI model adds more information to the data as it passes down the model. The data travels until it reaches the OSI model’s last layer. The data is transported through the network after receiving it at the last layer of the OSI architecture. The process will be reversed after receiving the data on the opposite side.

TCP/IP Model Overview 

TCP/IP (Transmission Control Protocol/Internet Protocol) allows you to specify how a particular computer connects to the internet and how data is transmitted. When many computer networks are linked together, it creates a virtual network. It was created primarily to provide a reliable end-to-end byte stream over an unreliable internet network.

The 7 layers of the OSI model 

7 layers of the OSI model in computer networking. OSI model vs TCP/IP model.

Physical – Layer 1

The physical layer defines the data connection’s electrical and physical characteristics. Examples of physical layers include: 

  • the pin configuration of a connector, 
  • the operating voltages of an electrical cable, 
  • optical fiber cable specifications, 
  • and the frequency for wireless devices. 

The physical layer is in charge of sending and receiving unstructured raw data across physical media and bitrate management. 

Network – Layer 3 

The network layer handles packet routing. It uses logical addressing and switching mechanisms. A network is a medium that allows multiple nodes to communicate with one another. Each node has a unique address. When a node needs to send a message to another node, it only needs to provide the message’s content and the destination node’s address, and the network will figure out how to get the message to the destination node. 

If a message is too long, the network:

  • splits it into numerous segments at one node, 
  • send each segment individually, 
  • and reassemble the fragments at a different node. 

Transport – Layer 4 

The transport layer is responsible for:

  • moving data sequences from a source to a destination host via one or more networks, 
  • preserving the quality of service (QoS) functions,
  • and ensuring complete data delivery. 

Error repair and equivalent functions are used to ensure data integrity. It also can provide explicit flow control. 

Session – Layer 5

The session layer manages computer conversations (connections). It creates,  maintains, and terminates connections between the local and distant applications. 

Layer 5 software handles authentication and authorization, ensuring that the data is delivered.

Presentation – Layer 6 

The presentation layer inspects the data to ensure it is compatible with the communications resources. It converts the data into a format that the application and lower levels can understand. The layer can also compress and encrypt data.

Application – Layer 7 

The OSI model’s application layer, closest to end-users, interacts directly with software applications to perform communication services as needed.

Functions of the application layer include:

  • Verifying the availability of communication resources. 
  • Facilitating data transfer.

TCP/IP model layers

Application Layer

The TCP/IP model’s application layer gives programs access to services provided by the other layers and defines the protocols that apps use to transmit data. Well-known application layer protocols include,

  • HTTP
  • FTP
  • SMTP
  • Telnet
  • DNS
  • SNMP
  • and Routing Information Protocol

Transport Layer

Firstly, the transport layer is in charge of providing session and datagram communication services to the application layer. TCP and UDP are the two most essential protocols on this tier. 

Additionally, TCP is a dependable, one-to-one, connection-oriented communications service. Furthermore, it is in charge of sequencing and acknowledging packets, and packet recovery and loss.

Internet Layer

The main protocols of the Internet protocol layer in the TCP/IP include:

  • Address Resolution Protocol (ARP) 
  • Internet Control Message Protocol (ICMP)
  • Internet Group Management Protocol (IGMP)

Firstly, an IP is a routable protocol that handles IP addressing, routing, packet fragmentation, and reassembly. Furthermore, it adds a header to the packets in this layer, known as the IP address.

ARP is in charge of determining the network access layer addresses. Likewise, ARP resolves MAC addresses in this layer. Whereas, the IP provides the hardware addresses.

In fact, the ICMP is in charge of delivering diagnostic features and reporting problems caused by failed IP packet delivery. Additionally, The IP Multicast Group Management Protocol (IGMP) is in charge of managing IP multicast groups. 

Network Access Layer

Here you can find TCP/IP packet operating and reception. Furthermore, another name is the link layer in the TCP IP model.

OSI model vs TCP/IP model

In conclusion, lets discuss the main difference in the OSI model vs TCP/IP model. Firstly, the most significant distinction between the two models is that the OSI model divides numerous functions into single layers. Conversely, the TCP/IP model does not. Additionally, the TCP/IP paradigm’s application and network access levels, both have several layers in the OSI model. 

Furthermore, you can use the OSI model to focus on a specific layer. For example, you can focus on the application layer, presentation layer, or session layer individually, to investigate data inconsistencies. Instead, the TCP/IP architecture combines the functions of these three layers making it hard to investigate inconsistencies.

FAQs about the OSI Model

At Which Layer of the OSI Model Do Hubs Operate?

Firstly, Hubs work at Layer 1 of the OSI model. Moreover, they are responsible for broadcasting incoming traffic to all ports. Ultimately, they route traffic to bridges and switches.

Which layer of the OSI Model are Network switches associated with?

In general, network switches are Layer 2 devices, so they operate at the Data Link Layer of the OSI model.
That being said, nowadays we do have also Layer 3 and Layer 4 switches. Layer 3 switches can basically perform routing functions in addition to switching, while Layer 4 Switches (in addition to the routing capabilities) enable policy-based features which allow traffic prioritization based on application importance.

Where Do Routers Operate in the OSI model?

A router is a layer 3 device. Additionally, a router operating at layer 3 examines incoming data packets’ IP and IPX addresses.

At which OSI model layer does a Firewall operate?

Firewalls operate at Layer 3, 4 and 7 of the OSI model. Firstly, a firewall operates at layer 3 since it can filter packets based on IP of origin or destination. Secondly, at layer 4 because you can filter based on TCP or UDP ports. Thirdly, it also operates on Layer 7 for packet inspection.

What part of the OSI Model Layer Does A Media Converter Operate?

Media converters operate at Layer 1 of the OSI model.

Hungry for more content? Learn more about what is SNMP, how does SNMP even work, how to find your SNMP OIDs, the differences between SNMP v2 vs v3 and what is a network management tool.

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