OSI Layer and TCP/IP Laboratorium Teknik Informatika – Universitas Gunadarma August, Stefanus Vlado Adi Kristanto Version 1.1

Networking Model The concept of layers is used to describe communication from one computer to another. The OSI and TCP/IP models have layers that explain how data is communicated from one computer to another. The models differ in the number and function of the layers. However, each model can be used to help describe and provide details about the flow of information from a source to a destination. The OSI model is used as a guide for understanding the communication process The Internet is developed by the standards of the TCP/IP protocols

Flow of Materials

Describe Data Communication In order for data packets to travel from a source to a destination on a network, it is important that all the devices on the network speak the same language or protocol. A protocol is a set of rules that make communication on a network more efficient.

Open System Interconnection Model Reduces complexity Standardizes interfaces Facilitates modular engineering Ensure interoperable technology Simplifies teaching and learning

OSI Layer - Physical

OSI Layer – Data Link

OSI Layer – Network

OSI Layer – Transport

OSI Layer – Session

OSI Layer – Presentation

OSI Layer – Application

TCP/ IP Model Reduces complexity Unlike the proprietary networking technologies mentioned earlier, TCP/IP was developed as an open standard. Although some of the layers in the TCP/IP model have the same name as layers in the OSI model, the layers of the two models do not correspond exactly.

TCP/ IP Application The application layer of the TCP/IP model handles high-level protocols, issues of representation, encoding, and dialog control.

TCP/ IP Application The transport layer provides transport services from the source host to the destination host.

TCP/ IP Application The purpose of the Internet layer is to select the best path through the network for packets to travel

TCP/ IP Application The network access layer is also called the host-to-network layer. The network access layer is the layer that is concerned with all of the issues that an IP packet requires to actually make a physical link to the network media.

TCP/IP Model

Detailed Encapsulation Process The information sent on a network is referred to as data or data packets. If one computer (source) wants to send data to another computer (destination), the data must first be packaged through a process called encapsulation.

Comparing TCP/IP with OSI Both have layers. Both have application layers, though they include very different services Both have comparable transport and network layers Packet-switched, not circuit-switched, technology is assumed Networking professionals need to know both models Similarities:

Comparing TCP/IP with OSI TCP/IP combines the presentation and session layer into its application layer TCP/IP combines the OSI data link and physical layers into one layer TCP/IP appears simpler because it has fewer layers TCP/IP transport layer using UDP does not always guarantee reliable delivery of packets as the transport layer in the OSI model Diferences:

End of Slides Laboratorium Teknik Informatika – Universitas Gunadarma