Osi physical layer pdf file

This article lists protocols, categorized by the nearest layer in the open systems. In the sevenlayer osi model of computer networking, the physical layer or layer 1 is the first and lowest layer. Media in category physical layer the following 6 files are in this category, out of 6 total. In fact, the layer doesnt know that any other layers even exist. The physical layer standards must define what type of signal represents a 1 and a 0. The physical layer is also concerned with the following. Networking osi model physical layer fundamental concepts. Describe the role of signals used to represent bits as a frame. The physical layer is the first and bottommost layer of the osi reference model. Networks network types protocol layering tcpip protocol suite osi model. Physical layer is the only layer of osi network model which actually deals with the physical connectivity of two different stations.

The number of layers should be large enough that distinct functions should not be put in the same layer and small. This layer is not concerned with the meaning of the bits and deals with the setup of physical connection to the network and with transmission and reception of signals. The physical layer includes cable specs, pinout patterns, voltages, hubs, repeaters, network cards, protocol standards rj45, v series modem standards and even host bus adapters hba. Physical layer in the osi model plays the role of interacting with actual hardware and signaling mechanism. For example, the network cable that you see is a part of the physical layer, the female. The physical layer consists of the basic networking hardware transmission technologies of a network. This layer defines the hardware equipment, cabling, wiring, frequencies, pulses used to represent binary. Electrical, mechanical, functional, and procedural specifications are provided for sending. The physical layer of the osi model defines connector and interface specifications, as well as the medium cable requirements. It is responsible for sending bits from one computer to another.

The method of representing the bits is called the signaling method. A layer should be created where different level of abstraction is needed. Physical layer of osi reference model studytonight. Each layer knows only about the layer above and below. Pdf osi physical layer network fundamentals chapter 8. Defines the electrical, mechanical, procedural, and functional specifications for activating, maintaining, and deactivating the physical link. The function of each layer should be chosen according to the internationally standardized protocols. The physical layer layer 1 sits at the bottom of the open systems interconnect. Furthermore, each layer can only communicate with the layers above and below it. A pdf file illustrating the relationship between common protocols and the osi.

Osi model 7 layers explained pdf layers functionsthe open systems interconnection model osi model is a conceptual model that characterizes and standardizes the communication functions of a telecommunication or computing system without regard to their underlying internal structure and technology. Layer 1 is the physical layer and, under the osi model, defines the physical and electrical characteristics of the network. Physical layer truly justifies its name because its actually physical in nature and tangible as well. The physical layer of the osi model is only part of a lan local area network. Physical layer is the lowest layer of the osi reference model. Starting from top to bottom apstndp stands for applicationpresentationsessiontransportnetworkdatalink physical. The purpose of the physical layer is to create the electrical, optical, or microwave. Lifewire colleen tighe at layer 1, the physical layer of the osi model is responsible for ultimate transmission of digital data bits from the physical layer of the sending source device over network communications media to the physical layer of the receiving destination device.