Week Four Individual Assignment
Kevin M. Gattas
University of Phoenix
IS Concepts
Richard Bohn

Purpose The importance of the OSI (open systems interconnection) model is for networks to communicate within the system. It is a system formed to allow a network administrator to perform trouble shooting in a way that is logical and step by step within the OSI model
Scope
The purpose of this essay is to break down the seven layers of the OSI model. The seven layer model defines a standard by which to computer share data over a network space starting with application layer. It will break each modeling section to lay out a more detailed explanation of how each layer is operated and how they all work together. Also, it will discuss which level this packet filtering routers and firewalls reside at, how packet filtering routers and firewalls protect the network and the concepts of cryptography. The seven layers of the OSI model are: 1. Physical layer 2. Data link layer 3. Network layer 4. Transport layer 5. Session layer 6. Presentation layer 7. Application layer Application Layer (Layer 7) The application layer is the most directly related to computer user because it is the top of the layer hierarchy. This layer provides several application services such as file transfer, resource allocation and whether the identification and verification of the computer is available. This layer is most familiar to us because it is what we commonly use to interact with the computer from a user standpoint. A good example of this layer is Outlook express.
Presentation Layer (Layer 6) The purpose of the presentation layer is to translate or "presents" data. This layer is also known by the operating system to ensure that information is delivered to the receiving machine in a form that can be understood. Some common functions in