1 / 4
Computer Service
2 / 4
Networking Service
3 / 4
Web Development Service
4 / 4
Software Development Service
TNW - ICT Solutions
  • Home
  • Available Courses 
  • Available Services 
  • Website Samples 
  • Search Log In
  • OSI Model
                         The Open System Interconnection (OSI) Model provides an abstract description of the network communication process. International Organization for Standard (ISO) develops it to provide a road map for non-proprietary protocol development. The OSI model is just a reference model and many of OSI protocols are no longer in use. There are seven layers in OSI Model. Those are as follows:

    Layer 7 -  Application
                            Performs services for the application used by the end users.

    Layer 6 -  Presentation
                           Provides data format information to the application.

    Layer 5 -  Session
                          Manages session between users.

    Layer 4 -  Transport
                         Defines data segments and numbers them at the source, transfers the data, and reassembles the data at the destination.

    Layer 3 -  Network
                        Creates and addresses packets for end-to-end delivery through intermediary devices in other network.

    Layer 2 - Data Link
                        Creates and addresses frames for host-to-host delivery on the local LANs and between WAN devices.

    Layer 1 - Physical
                        Transmits binary data over media between devices. Physical layer protocols define media specifications.

    TCP/IP Model
                        TCP / IP is an open standard. The rules and implementation of the TCP/IP model were cooperatively developed by members of the industry using Request for Comments (RFC) documents. There are four layers in TCP/IP Model. Those are as follows:

    Layer 4 -  Application
                       Represents application data to the user.

    Layer 3 - Transport
                    Supports communication between devices and performs error correction.

    Layer 2 - Internet
                       Finds the best path through the network.

    Layer 1 - Network access
                      Controls hardware devices and media.


    Comparison of OSI and TCP / IP Model

      7.  Application     4. Application
      6.  Presentation
      5.  Session
      4.  Transport
       3. Transport
      3.  Network    2.  Internet
      2.  Data Link    1. Network Access
      1.  Physical