1. Elective 2 – Windows Server Management By: Aaron Angeles

2. OSI Layers Network Terms Subnets Topics

3. Multimedia – OSI Layers media276_1_A_OSI.htm OSI

4. Begins by 1978 to define a unifying standard for the architecture of networking systems International Telegraph and Telephone Consultative Committee and International Organization for Standardization (ISO) Officially rolled out by ISO as Open Systems Interconnection model by 1984. OSI Layers

5. OSI Layers 7 Layers: 7 - Application 6 - Presentation 5 - Session 4 - Transport 3 - Network 2 - Data-Link 1 - Physical “All PeopleSeem To Need Data Processing”

6. Each layer defines networking tasks Each layer communicates with the layers above and below it Layer 7 provides services for programs to gain access to the network Layers 1 & 2 define the network’s physical media and related tasks OSI

7. Application Layer ( Layer 7) Provides an entrance point for programs (e.g. web browsers, e-mail system) to gain network services Represent application programming interfaces (APIs) that developers can use to perform network functions when building applications OSI

8. Presentation (Layer 6) Translates data between computing systems on a network Performs: – data encryption – data compression – data conversion OSI

9. Session (Layer 5) Enables two application to create a persisten communication connections. Ensures that both sender and receiver are ready to communicate OSI

10. Transport (Layer 4) Ensures packets are delivered in order in which they are sent without loss or duplication. On the sending side, this layer is responsible for braking down larger messages into smaller packets for transmission On the receiving end, this layer is responsible for reassembling the packets into a single message to pass up to the upper layer OSI

11. Network (Layer 3) Determines the physical path of the data to be transmitted based on the network conditions, priority of server and other factors. The only layer that uses logical networking and can move packets between different networks. OSI

12. Data-link (Layer 2) Provides error free transfer of data frames from one computer to another over the physical layer. The Media Access Control (MAC) address of the network card exists at this layer that is added to the packet to create a frame. OSI

13. Physical Layer (Layer 1) Establishes the physical interface and mechanisms for placing a raw stream of data bits on the network cabling. OSI

14. TCP/IP in Relation with OSI OSI