OSI Reference Model
This lesson covers the OSI reference model. It is sometimes also called ISO or 7 layer reference model. The model was developed by the International Standards Organization in the early 1980’s. It describes the principles for interconnection of computer systems in an Open System Interconnection environment.
Layers 5– 7: Session, Presentation, and Application Layers Let’s look at the upper layers of the OSI seven layer model now. Those layers are the transport, session, presentation,
Transport services allow users to segment and reassemble several upper-layer applications onto the same transport layer data stream. It also establishes the end-to-end connection, from your host to
The next two examples will bring together many of the concepts we have discussed. The network layer must relate to and interface with various lower layers. Routers must
Static Versus Dynamic Routes Routers must be aware of what links, or lines, on the network are up and running, which ones are overloaded, or which ones may
Network Layer Protocol Operations Let’s take a look at the flow of packets through a routed network. For examples sake, let’s say it is an Email message from
Layer 3: Network Layer Now let’s take a look a layer 3–the domain of routing. Network Layer: Path Determination Which path should traffic take through the cloud of
Layers 1 & 2: Physical & Data Link Layers Now let’s take a look at each of the layers in a bit more detail and with some context.
Let’s see how these layers work in a Peer to Peer Communications Network. In this exercise we will package information and move it from Host A, across network
– Application Layer If we take a look at the model from the top layer, the Application Layer, down, I think you will begin to get a better
Why a Layered Network Model………? That’s essentially the same thing that goes in networking with the OSI model. This image illustrates the model. So, why use a layered