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Tham khảo bài thuyết trình 'introduction a communications model', công nghệ thông tin, quản trị mạng phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | INTRODUCTION A Communications Model Source generates data to be transmitted Transmitter Converts data into transmittable signals Transmission System Carries data Receiver Converts received signal into data Destination Takes incoming data Simplified Communications Model - Diagram Simplified Data Communications Model Networking Point to point communication not usually practical Devices are too far apart Large set of devices would need impractical number of connections Solution is a communications network Simplified Network Model Wide Area Networks Large geographical area Crossing public rights of way Rely in part on common carrier circuits Alternative technologies Circuit switching Packet switching Frame relay Asynchronous Transfer Mode (ATM) Network Models Multi-layer Network Models The process of transferring a message between sender and receiver is more easily implemented by breaking it down into simpler components. Instead of a single layer, a group of layers are used, dividing up . | INTRODUCTION A Communications Model Source generates data to be transmitted Transmitter Converts data into transmittable signals Transmission System Carries data Receiver Converts received signal into data Destination Takes incoming data Simplified Communications Model - Diagram Simplified Data Communications Model Networking Point to point communication not usually practical Devices are too far apart Large set of devices would need impractical number of connections Solution is a communications network Simplified Network Model Wide Area Networks Large geographical area Crossing public rights of way Rely in part on common carrier circuits Alternative technologies Circuit switching Packet switching Frame relay Asynchronous Transfer Mode (ATM) Network Models Multi-layer Network Models The process of transferring a message between sender and receiver is more easily implemented by breaking it down into simpler components. Instead of a single layer, a group of layers are used, dividing up the tasks required for network communications. The two most important such network models are the OSI and Internet models. The OSI Reference Model Stands for Open Systems Interconnection Created by the International Standards Organization (ISO) as a framework for computer network standards Released in 1984, the model has 7 layers The OSI 7-layer Model Application: provides a set of utilities used by application programs Presentation: formats data for presentation to the user, provides data interfaces, data compression and translation between different data formats Session: responsible for initiating, maintaining and terminating each logical session between sender and receiver Transport: deals with end-to-end issues such as segmenting the message for network transport, and maintaining the logical connections between sender and receiver Network: responsible for making routing decisions Data Link: deals with message delineation, error control and network medium access control Physical: .
