It 242 Week 1 Checkpoint Osi Model

OSI ModelStephen D, JamesIT-242 John TinneyJune 24, 2011University of Phoenix (Axia College)OSI Model With the goal of standardizing the world of networks, the International Organization for Standardization (ISO) began development of the open systems interconnection (OSI) reference model (Regan, 2004). After analyzing the seven layers of the OSI model it is seen that layer three is where WAN protocols operate on; layer three is also known as the network layer. The network layer performs routing functions and identifies end-to-end addressing and routing datagram’s. The Network Layer performs network routing functions and might also perform fragmentation and reassembly, it also reports delivery errors. There is a unit called a brouter that some layers contain which functions as a router and a bridge. Routers and switches operate on layers 2-4 (data link layer, network layer and transport layer). The Data Link Layer provides the function to transfer data between networks and to detect and maybe correct errors that may occur in the Physical Layer. Originally this layer was intended for point-to-point and point-to-multipoint media characteristics of wide area media in the telephone system. On layer three