Layer 1: Physical Layer OSI model

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the physical layer defines electrical , physical specifications of data connection. defines relationship between device , physical transmission medium (for example, electrical cable, optical fiber cable, or radio frequency link). includes layout of pins, voltages, line impedance, cable specifications, signal timing , similar characteristics connected devices , frequency (5 ghz or 2.4 ghz etc.) wireless devices. responsible transmission , reception of unstructured raw data in physical medium. bit rate control done @ physical layer. may define transmission mode simplex, half duplex, , full duplex. defines network topology bus, mesh, or ring being of common.


the physical layer layer of low-level networking equipment, such hubs, cabling, , repeaters. physical layer never concerned protocols or other such higher-layer items. examples of hardware in layer network adapters, repeaters, network hubs, modems, , fiber media converters.







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