Data Communications and Networking

Other Applications (Data Communications and Networking)

There are literally thousands of applications that run on the Internet and on other networks. Most application software that we develop today, whether for sale or for private internal use, runs on a network. We could spend years talking about different network applications and still cover only a small number. Fortunately, most network application software […]

Implications For Management (Data Communications and Networking)

The first implication for management from this topic is that the primary purpose of a network is to provide a worry-free environment in which applications can run. The network itself does not change the way an organization operates; it is the applications that the network enables that have the potential to change organizations. If the […]

Physical Layer (Data Communications and Networking)

The Physical layer [also called layer 1) is the physical connection between the computers and/or devices in the network. This topic examines how the physical layer operates. It describes the most commonly used media for network circuits and explains the basic technical concepts of how data is actually transmitted through the media. Four different types […]

Circuits (Data Communications and Networking)

Circuit Configuration Circuit configuration is the basic physical layout of the circuit. There are two fundamental circuit configurations: point-to-point and multipoint. In practice, most complex computer networks have many circuits, some of which are point-to-point and some of which are multipoint. Figure 3.1 illustrates a point-to-point circuit, which is so named because it goes from […]

Communication Media (Data Communications and Networking)

The medium (or media, if there is more than one) is the physical matter or substance that carries the voice or data transmission. Many different types of transmission media are currently in use, such as copper (wire), glass or plastic (fiber-optic cable), or air (radio, infrared, microwave, or satellite). There are two basic types of […]

Digital Transmission of Digital Data

All computer systems produce binary data. For these data to be understood by both the sender and receiver, both must agree on a standard system for representing the letters, numbers, and symbols that compose messages. The coding scheme is the language that computers use to represent data. Coding A character is a symbol that has […]

Analog transmission of digital data (Data Communications and Networking)

Telephone networks were originally built for human speech rather than for data. They were designed to transmit the electrical representation of sound waves, rather than the binary data used by computers. There are many occasions when data need to be transmitted over a voice communications network. Many people working at home still use a modem […]

Digital transmission of analog data (Data Communications and Networking)

In the same way that digital computer data can be sent over analog telephone networks using analog transmission, analog voice data can be sent over digital networks using digital transmission. This process is somewhat similar to the analog transmission of digital data. A pair of special devices called codecs {code!decode) is used in the same […]

Implications for management (Data Communications and Networking)

In the past, networks used to be designed so that the physical cables transported data in the same form in which the data was created: analog voice data generated by telephones used to be carried by analog transmission cables and digital computer data used to be carried by digital transmission cables. Today, it is simple […]

Data Link Layer (Data Communications and Networking)

The Data link layer [also called layer 2] is responsible for moving a message from one computer or network device to the next computer or network device in the overall path from sender or receiver. It controls the way messages are sent on the physical media. Both the sender and receiver have to agree on […]