OSI......

Internetworking is not all about physical things, one needs to put some things together before internetworking can be achieved. Let examine the OSI layers and see how it works


The SEVEN (7) Layers of the OSI Model
APLICATION LAYER 7
PRESENTATION LAYER 6
SESSION LAYER 5
TRANSPORT LAYER 4
NETWORK LAYER 3
DATALINK LAYER 2
PHYSICAL LAYER 1


The Quick Summary of the OSI layer
Application: - This is responsible for determining when access to the network is required.

Presentation: - This ensures data is received in a useable format. Data encryption is done more.

Session: - This establishing and maintaining connections. It also responsible for ports and ensures queries for services.

Transport: - Breaks data into frames and assigns sequence numbers. Also checks for errors in data received. UDP (User Datagram Protocol) and SPX (Sequenced Packet Exchange) are protocols that work on this layer.

Network: - How systems on different network segments find each other. Source Destination addresses. Subnets, Path determination exist at this layer. IP (Internet Protocol) and IPX (Internetwork Packet Exchange) protocols used here.

Datalink: - frame exist here. This layer handles flow control. Specifies topology and provides hardware addressing-Mac.

Physical: this transmission of the raw bit stream. Electrical signaling and hardware interface.