OSI Model

 

 

1.      Short for Open System Interconnection, OSI is a network model developed by ISO in 1978 in which peer-to-peer communications are divided into seven layers. Each layer performs a specific task or tasks, and builds upon the preceding layer until the communications is complete. Below are the purposes of each of the seven layers. 1 – Physical layer  – responsible for the electrical, mechanical and timing across the link. 2 – Data link layer (also known as the link layer) – responsible for transmitting data across a link. 3 – Network layer – responsible for routing information through the network and allowing systems to communicate. 4 – Transport layer – responsible for transferring information between endpoints on the network and deals with errors such as lost or duplicate packets. 5 – Session layer – responsible for managing a session between two applications. 6 – Presentation layer – responsible for the data formatting and display, allowing for compatibility. 7 – Application layer -  responsible for user interaction. An example of an OSI application is the FTAM.   2.      Short for Open-Source Initiative, OSI is a non-profit corporation dedicated to managing and promoting Open Source. Their page can be found at http://www.opensource.org/.