Simnet Chapter 8

TCP/IP (transmission control protocol/Internet protocol).

The essential features of this protocol involve (1) identifying sending and receiving devices and (2) breaking information into small parts, or packets, for transmission across the Internet.

transfer rate

The speed with which modems transmit data varies.

Data transmission specifications

These are rules and procedures that coordinate the sending and receiving devices by precisely defining how the message will be sent across the communication channel.

Connection devices

These devices act as an interface between the sending and receiving devices and the communication channel.

digital signals

These represent the presence or absence of an electronic pulse, typically used by computers

Voiceband

also known as low bandwidth, is used for standard telephone communication.

Third-generation mobile telecommunications (3G)

in the 2000s and provided services capable of effective connectivity to the Internet, marking the beginning of smartphones.

Network Gateway

is a device that allows one LAN to be linked to other LANs or to larger networks.

Bandwith

is a measurement of the width or capacity of the communication channel.

WiMax (Worldwide Interoperability for Microwave Access)

is a new standard that extends the range of Wi-Fi networks using microwave connections.

extranet

is a private network that connects more than one organization.

intranet

is a private network within an organization that resembles the Internet.

Bluetooth

is a short-range radio communication standard that transmits data over short distances of up to approximately 33 feet.

Fifth-generation mobile telecommunications (5G)

is being developed, with speeds that rival home Internet connections and is expected to be widely available by 2020.

Cable Service

is provided by cable television companies using their existing television cables. These connections are usually faster than DSL.

Digital subscriber line (DSL) service

is provided by telephone companies using existing telephone lines to provide high-speed connections.

Modem

is short for modulator-demodulator.

Fiber-optic service (FiOS)

is showing up in some areas, but it is a new technology and not widely available. Current providers include Google and Verizon with speeds faster than cable or DSL connections.

Modulator

is the name of the process of converting from digital to analog.

Demodulator

is the process of converting from analog to digital.

Mediumband

is used in special leased lines to connect midrange computers and mainframes, as well as to transmit data over long distances.

Broadband

is widely used for DSL, cable, and satellite connections to the Internet.

Baseband

is widely used to connect individual computers that are located close to one another.

Network administrators

manage a company's LAN and WAN networks.

peer-to-peer (P2P) network

nodes have equal authority and can act as both clients and servers.

ADSL (asymmetric digital subscriber line)

one of the most widely used types of DSL. DSL is much faster than dial-up.

T1, T3 (DS3), and OC (optical carrier) lines

provide support for very-high-speed, all-digital transmission for large corporations.

Metropolitan area networks (MANs)

span distances up to 100 miles.

First-generation mobile telecommunications (1G)

started in the 1980s using analog radio signals to provide analog voice transmission service.

Second-generation mobile telecommunications (2G)

started in the 1990s using digital radio signals.

Cellular service providers

support voice and data transmission to wireless devices using cellular networks.

Communication channel

the actual connecting or transmission medium that carries the message.

wireless modem

Almost all computers today have this modem built-in.

Packetization

Information sent or transmitted across the Internet usually travels through numerous interconnected networks.

Network administrator

a computer specialist responsible for efficient network operations and implementation of new networks.

Coaxial Cable

a high-frequency transmission cable, replaces the multiple wires of telephone lines with a single solid-copper core.

Router

a node that forwards or routes data packets from one network to their destination in another network.

Client

a node that requests and uses resources available from other nodes.

Server

a node that shares resources with other nodes.

Directory server

a specialized server that manages resources, such as user accounts, for an entire network.

Host

any computer system connected to a network that provides access to its resources.

Node

any device that is connected to a network.

Wide area networks (WANs)

are countrywide and worldwide networks.

Communication Systems

are electronic systems that transmit data from one location to another

Protocols

are the rules for exchanging data between computers

Switch

central node that coordinates the flow of data by sending messages directly between sender and receiver nodes.

Microwave

communication uses high-frequency radio waves.

Cellular

communication uses multiple antennae (cell towers) to send and receive data within relatively small geographic regions (cells).

Firewall

consists of hardware and software that control access to a company's intranet and other internal networks.

Twisted-pair cable

consists of pairs of copper wire that are twisted together. Both standard telephone lines and Ethernet cables use this.

Network operating systems (NOS)

control and coordinate the activities of all computers and other devices on a network.

domain name server (DNS)

converts text-based addresses to IP addresses.

Virtual private networks (VPN)

create a secure private connection between a remote user and an organization's internal network.

Network architecture

describes how a network is arranged and how resources are coordinated and shared

Star network

each device is connected directly to a central network switch.

Tree network

each device is connected to a central node, either directly or through one or more other devices.

Bus network

each device is connected to a common cable called a bus or backbone, and all communications travel along this bus.

Ring network

each device is connected to two other devices, forming a ring.

Network interface cards (NIC)

these are expansion cards located within the system unit that connect the computer to a network. also known as a lan adapter

Mesh Network

this topology is the newest type and does not use a specific physical layout (such as a star or a tree). Rather, the mesh network requires that each node have more than one connection to the other nodes.

fiber-optic cable

transmits data as pulses of light through tiny tubes of glass.

Fourth-generation mobile telecommunications (4G)

use LTE (Long Term Evolution) connections to provide faster Internet access, allowing smartphones to easily stream videos and music.

Satellite connection services

use satellites to provide wireless connections. Although slower than DSL

Wi-Fi (wireless fidelity)

uses high-frequency radio signals to transmit data.

DSL (digital subscriber line) modem

uses standard phone lines to create a high-speed connection directly to your phone company's offices.

cable modem

uses the same coaxial cable as your television.

Dial-up services

using existing telephones and telephone modems to connect to the Internet.

analog signals

which are continuous electronic waves, typically used by telephones

Intrusion detection systems (IDS)

work with firewalls to protect an organization's network.