IntroThe Open Systems Interconnection (OSI) reference model significantly influenced the development of the Internet Protocol we use today. Created in the 1980s by the International Standards Organization (ISO), a multinational body dedicated to worldwide agreement on international standards, this reference model defined the entire network communication process into seven structured levels. In ascending order these layers are the physical, data link, network, transport, session, presentation, and application layers. The purpose of this model was, and still is, to simplify and establish a standard for designing communications and networking products that can communicate with each other, regardless of system differences. Layer Functions The open systems interconnection model divides host-to-host transmissions into seven different layers where each performs a specific function. At the same time each layer has the ability to also communicate with adjacent layers in both directions. In essence, each layer interacts directly with the one below it and at the same time also provides support to the layer above it.1. Physical Layer The first layer in the OSI model is the physical layer, which is primarily concerned with all hardware aspects of communication, essentially defining standards for signaling and cabling. The main purpose of this layer is to handle the translation of the binary bits in each frame into signals. And then transmit these signals one at a time over a physical medium that connects other network entities. On the receiving side, the physical layer will recover these individual signals and restore them to their bit representations before transmitting them to the data link layer as a complete frame. The ... middle of paper ... methods can be used by applications, such as HTTP for web browsers or SMPT for email. This layer is essentially responsible for integrating network functionality and providing network services to the user's system and does not involve any real applications. Other standards established by the application layer include the file transfer protocol (FTP), used to transfer files from one system to another. And Domain Name Service (DNS), which is a network service that translates domain names into their IP addresses. Works Cited http://www.dummies.com/how-to/content/osi-model-for-cisco-networking.html http ://support.microsoft.com/kb/103884 http://www.dummies. com/how-to/content/network-basics-the-seven-layers-of-the-osi-referen.html OSI Model Explained http ://www.youtube.com/watch?v=O_rsqVtaloI http://en .wikipedia.org/wiki/OSI_model http://www.webopedia.com/quick_ref/OSI_Layers.asp