A Data Communication System
Defines a data communication system. Gives an overview of its components, and describes the path a transaction takes in the system.
| Introduction: Description of a data communication system. Components of a data communication system. |
The Remote Site
Discusses the terminal and the controller at the remote site. Explains how they operate in a data communication system.
| The Terminal: Identification of the functions of a terminal. |
| The Controller: Identification of the functions of a controller. Definition of buffering. Cyclical Redundancy Checking. |
The Connection
Describes the modem and telephone line that link a terminal to its host computer.
| The Modem: The functions of a modem. How to distinguish bits from bytes. Explanation of modulation and demodulation. |
| The Telephone Line: Dial-up and leased telephone line connections. |
The Host Site
Discusses the front-end processor and the host computer at the host site. Explains how they operate in a data communication system.
| The Front-end Processor: The functions of a front-end processor. The functions of a line protocol. Definition of polling. |
| The Host Computer: Identification of the functions of a host computer. Description of a TP monitor. Identification of the functions of an application program. |
The Big Picture
Follows a transaction to see how it is processed in a data communication system. Poses questions which relate to each stage of the process.
| Practice: Entering a transaction. Seeing how a transaction is processed. |
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