1) This is the lowest level of the network structure which is compromised or the physical and logical mechanisms for the transport of data. many different technologies exist in this area.
2) Examples include CAT5 copper cabling with 10Base T Ethernet carrier protocols, fiber optics with the fiber distributed data interface protocol or one of the many frame relay systems.
3) This includes devices that connect similar and dissimilar network systems search is bridges hubs, routers repeaters switches and modems. Devices that connect end system servers to the carrier services such as network interface cards channel service units data service units and special function hardware such as firewalls.
4) This provides most of the intelligence, scheduling and sharing services for the network. the network operating system is highly configurable and must support and bind closely with other network components and the security systems
5) More than one NOS may be required in a solution and some may even be built into intelligent connectivity hardware.
Examples include Microsoft Windows Unix and Linux. These systems control, monitor and maintain the network and often closely with the network operating system.