CertiGuide to A+ (A+ 4 Real)  9  Chapter 13: Basic Networking Terminology

Chapter 13: Basic Networking Terminology 1 Cables and Fibers

The existence of today’s network is due to the continuous evolution in computer technology.

The first computers built in the 1950’s were very bulky and expensive and intended only for Government or University use. They were not intended for interactive work between business users, nor were they used in the packet-processing mode. As a rule, they were built on a mainframe basis - a powerful and reliable room sized server with a universal purpose. Users prepared punch cards containing data and program commands then transferred them to the computer service bureau. The operators then entered these cards into the computer, and the users received results after some waiting. The overall performance of this expensive process (called batch jobs) was crucial to the accurate performance of its users.

In the beginning of the 1960’s, simultaneously with the decrease of the prices of processors, business computer usage appeared, which took into account the interests of business needs and interactive multi-terminal systems for workload division. Several users shared the mainframe’s resources at a time. Each user could work individually with the mainframe through a terminal. The mainframe’s reaction time was so quick that the user almost did not notice the parallel work with other users. With this concept, the computing capacity remained centralized, but some of its functions became distributed. These multi-terminal systems became the ancestors of a new widely developing technology, “thin clients”, through which all information processing is carried out by one powerful computer, and the actual input/output operations performed by terminal stations having a minimal configuration of hardware and software.

In modern networks, the information processing is divided between either clients or servers. This model refers to the client – server relationship. The server is the one specialized powerful computer that provides the information that the client computers require. The client is the computer initiating the inquiry. This concept causes concern in relation to software sharing, as some OS’s require that one computer has to be the server, and all computers in the network called the clients. In addition, peer-to-peer networks exist where computer can be both client and/or server.¹⁷¹

The multi-terminal systems become a first step on the path of creating the modern network, however, the requirement that the terminals be connected with distant computers has gradually appeared, and the communications through telephone networks now comes through modems. (Even though the original meaning of “modem” meant modulator/demodulator, which is not performed in a straight digital connection, the devices used in xDSL and cable access are still called modems). The need for an automatic exchange of data had appeared. This mechanism relied on an exchange of files, synchronizing databases, and electronic mail between computers, (with the exception of the computer acting as the connection terminal). The entire network services mentioned became traditional needs.

In the beginning of the1970’s there was a lull in computer development¹⁷², and then large-scale integrated circuits appeared. (Up to this time, individual processors for each task were the norm, i.e. a processor for math functions, a processor for logic functions, etc.) The low cost and high functionality of the new integrated chips resulted in the creation of the mini-computer, which became the real competitor to the mainframe. Ten mini-computers carried out a task in parallel faster then one mainframe and had on top a lower overall cost.

Users now begin to realize that they would like to accept and transfer data with neighboring computers, which started the first stages of local networks. Companies thus began connecting users to each other, creating the first Peer-to Peer LANs. LAN (Local Area Network) is a group of workstations, PDA's (Personal Digital Assistant), terminals, printers, and other devices, incorporated into sharing a high-speed data medium that covers a relatively small geographic area.

Chapter 13: Basic Networking Terminology 1 Cables and Fibers