OSI Model
The Open Systems Interconnection (OSI) model is a conceptual model that describes the universal standard of communication functions of a telecommunication system or computing system, without any regard to the system's underlying internal technology and specific protocol suites. The OSI model has seven layers described below, and helps:
• Determine the required hardware and software to build their Network.
• Understand and communicate the process followed by components communicating across a network.
• Perform troubleshooting, by identifying which Network Layer is causing an issue and focusing efforts on that layer.
Fiber Optic
A network switch connects devices within a network and forwards data frames to and from those devices. Unlike a router, Layer 2 switch only understands communication with devices directly connected to it; Layer 2 has no concept of sources or destinations "farther away" on the network. Network switches can operate at either OSI layer 2 (the data link layer) or layer 3 (the network layer). Layer 2 switches forward data based on the destination MAC address. Layer 3 switches forward data based on the destination IP address, effectively making them routers. Some switches can do both, operating at both OSI layers 2 and 3.
OSI Model – Network Layer L3
The network layer is responsible for the end-to-end delivery of data between the originating device and the final destination. Routers forward packets by discovering the best path across a physical networks. The network layer uses network addresses (typically Internet Protocol addresses) to route packets
Network Router is the device associated to Network Layer
A router is a device that connects two or more packet-switched networks or subnetworks. Routers manage traffic between these networks by forwarding data packets towards their intended destination IP addresses. In order to direct packets effectively, a router uses an internal routing table — a list of paths to various network destinations. The router reads a packet's header to determine where it is going, then consults the routing table to figure out the most efficient path to that destination. It then forwards the packet to the next network in the path.
