A network is a collection of computers and devices connected together via communications devices and transmission media. Many businesses network their computers together to facilitate communications, share hardware, share data and information, share software, and transfer funds.
Which one is a collection of computers and devices connected together often wirelessly via communications devices and transmission media?
A network is a collection of computers and devices connected together, often wirelessly, via communications devices and transmission media. Application consists of programs designed to make users more productive and assist them with personal tasks.
What is a group of computers that communicate together called?
Explanation: network is a group of computers connected together. The internet is sometimes called a network of networks. It connects computers all over the world mostly using the World Wide Web (www).
Is the collection of computers?
Answered: A network is a collection of computers…
What must a client computer do to receive services from a server?
What must a client computer do to receive services from a server? It must request them. In case something goes wrong during processing, you can include a __________ handler in a webpage script.
What is the collection of computer?
Answer: A collection of computer programs is called software which contains instructions for the computer.
What is a collection of computers called?
A collection of computer programs, libraries, and related data are referred to as software. Computer programs may be categorized along functional lines, such as application software and system software.
Is there a device that connects multiple computers?
Answer: Switch. A switch, like a hub, is a device that connects a number of computers together to make a LAN. The typical use of a switch is at the centre of a star network (or as part of a hybrid network) – the switch has cables plugged into it from each computer.
Which is a collection of computers and devices?
A (n) _____ is a collection of computers and devices connected together via communications devices and transmission media. Chapter 10, Problem 2SG is solved.
How are computers and devices connected in a network?
Network collection of computers and devices connect together via communication devices and transmission media Facilitate Communication using a network, people communicate efficiently and easily via email, IM, blogs, etc. Share Hardware
What is the configuration of computers, devices, and media called?
The configuration of computers, devices, and media in a network is sometimes called the ____. network architecture 21. Digital ____ lines include cable television lines, DSL, ISDN lines, FTTP, T-carrier lines, and ATM. dedicated
What makes a sending device a receiving device?
Sending Device initiates an instruction to transmit data, instructions, or information Communications Channel the data, instructions or information travel Receiving Device accepts the transmission of data, information and instructions Network collection of computers and devices connect together via communication devices and transmission media
Presentation on theme: "Networks A network is a collection of computers and devices connected together via communications devices and transmission media Advantages of a network."— Presentation transcript:
1 Networks A network is a collection of computers and devices connected together via communications devices and
transmission media Advantages of a network include: Facilitating communications Sharing hardware Sharing data and information Sharing software Transferring funds
2
3 Bandwidth Measurement of the capacity of the channel Categories
Voiceband also known as low bandwidth Medium band Broadband Used for high capacity transmission Used by DSL, cable, and
satellite Several technical matters affect data communications One is bandwidth – bits-per-second (bps) transmission capability of a channel Three types: Voiceband – also known as low bandwidth; standard phone line; too slow for many types of transmissions – especially high-quality video; typical speeds are 56 to 96 kbps Medium band – with special leased lines to connect minicomputers and mainframes as well as to transmit data over
long distances (for larger computer systems); not typically used by individuals Broadband – used for high-capacity transmissions (DSL, cable, satellite connections); specialized high-speed devices; effectively transmits high-quality video and other communication needs; typically 1.5 mbps; higher speeds possible
4 Protocols Set of communication rules
Standard for Internet: TCP/IP (Transmission control protocol/Internet protocol) Identification Reformatting Rules for exchanging data between computers Essential features of protocol
Identification - Identifying sending and receiving devices (IP address); (key term) Internet unique number address; domain name server (DNS) (key term) converts text-based addresses to IP addresses Reformatting – allows message to be broken into so easier to transmit over Internet through various interconnected networks; allows message to be reassembled at destination
5 Network Classifications
Local area networks (LAN) Home networks WLAN (Wireless LAN) Metropolitan area networks (MAN) Wide area networks (WAN)
6 Network Classifications
A local area network (LAN) is a network that connects computers and devices in a limited geographical area A wireless LAN (WLAN) is a LAN that uses no physical wires
7 Network Classifications
A metropolitan area network (MAN) connects LANs in a metropolitan area A wide area network (WAN) is a network that covers a large geographical area
8 Network Architecture The design of computers, devices, and media on a network is sometimes called the network
architecture Client/server Peer-to-peer Terminal
9 Peer-to-peer (P2P) Model
Client/Server Model Client Server Peer Peer Peers communicate as equals on a one-to-one basis.
Server must be prepared to serve multiple clients at any time.
10 The Client/Server Model
When processes need to communicate: Examples: file server mail server web server =>
11 The Client/Server Model (continued)
Client & server have strictly defined roles: client sends request – then waits for answer server accepts request – processes & returns answer Protocols, defining how to: encode messages
address messages handle sending and receiving Protocols: Example http, ftp
12 The Peer-to-peer Model
P2P describes an Internet network on which users access each other’s hard disks and exchange files directly over the Internet
13 Network Topology A network topology refers to the layout of the computers and devices in a communications network Star
network Bus network Ring network
14 Network Topology
Network topology is the layout pattern of interconnections of the various elements (links, nodes, etc.) of a computer. Types of network topology Star Bus Ring Hierarchical Networks are connections of two or more computers that work together to exchange information and share resources The network architecture describes how the network is arranged and how the resources are coordinated
and shared Network architecture also describes how a computer network is configured and what strategies are used Topology – network arrangement or configuration
15 Star Network Smaller computers linked to a central
unit
Central unit is called the network hub Control is maintained by polling Host computer – large centralized computer, usually a mainframe Star network (Key Term) – nodes are connected to a single computer called a network hub All communications pass through the hub/host computer; each connecting device is asked (“polled”) whether it has a message to send and then each device is in turn allowed to send its message
Can be used as a time-sharing system (key term)
16 Bus Network Each device handles its own communication control
There is no host computer Has a common connecting cable called a backbone Bus
network (key term)– each device handles its own communications control No host computer Common connecting cable called a bus or backbone Not as efficient as star, but it is low cost and widely used
17 Ring
Network Each device is connected to two other devices
No central file server or computer Useful in a decentralized environment Ring network (key term) Each device connected to two others forming a ring No central files server or computer Messages passed around ring until reach correct destination Often used to link mainframes—especially over wide geographical areas Useful in decentralized
organization Makes possible distributed data processing system (key term) Computers can perform processing tasks on own Can also share programs, data, and other resources
18 Hierarchical Network
Several computers linked to a central host
Computers are hosts to other computers Useful in centralized organizations Hierarchical Network (key term) Sometime called hybrid network Consists of several computers linked to central host computer All computers can server as hosts to other computers (unlike star network) Host at top could be mainframe; computers below could be minis; then “down” to
micros Useful in centralized organization Page 264
19 Principal Network Configurations
No instructor notes
20 Network Communications Standards
Ethernet Token ring TCP/IP Wi-Fi Bluetooth UWB IrDA RFID WiMAX WAP
21 Network Communications Standards
Ethernet is a network standard that specifies no computer controls when data can be transmitted The token ring standard specifies that computers and devices on the network share or pass a special signal (token) TCP/IP is a network standard that
defines how messages are routed from one end of a network to another
22 Network Communications Standards
23
Network Communications Standards
Wi-Fi identifies any network based on the standard that facilitates wireless communication Sometimes referred to as wireless Ethernet
24 Network Communications Standards
Bluetooth defines how two
Bluetooth devices use short-range radio waves to transmit data UWB (ultra-wideband) specifies how two UWB devices use short-range radio waves to communicate at high speeds IrDA transmits data wirelessly via infrared (IR) light waves RFID uses radio signals to communicate with a tag placed in or attached to an object, animal, or person
25 Network Communications Standards
26 Network Communications Standards
WiMAX (802.16) Developed by IEEE Towers can cover a 30-mile radius Two types are fixed
wireless and mobile wireless Provides wireless broadband Internet access Wireless Application Protocol (WAP) Specifies how some mobile devices can display the content of Internet services Web Chat rooms Uses a client/server network
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Communications Software
Communications software consists of programs that: Help users establish a connection to another computer or network Manage the transmission of data, instructions, and information Provide an interface for users to communicate with one another
28 Communications Over the Telephone Network
The public switched telephone network (PSTN) is the worldwide telephone system
29 Communications Over the Telephone Network
Dial-up lines Dedicated line ISDN line DSL FTTP T-carrier line ATM
30 Communications Over the Telephone Network
31 Communications Over the Telephone
Network
ADSL connections transmit data downstream at a much faster rate than upstream
32 Home
Networks Home networks provide computers with the following capabilities: Connect to the Internet at the same time Share a single high-speed Internet connection Access files and programs on other computers Share peripherals Play multiplayer games Connect game consoles to the Internet Subscribe to and use VoIP
33 Home Networks
34 Organizational Internets
Intranets Private network within an organization Provides information to employees
Extranets Private network that connects organizations Used to allow suppliers and others access Firewalls Security system Protects against external threats Intranet – Intranets use browsers, Web sites, and Web pages like the public Internet; typically include , mailing lists, newsgroups, and FTP services Extranet – Purpose is to increase efficiency and reduce costs Firewalls –
Organizational firewalls include a proxy server (key term) that is a gatekeeper; all communications between the outside world and an organization must pass through the proxy server where the source and content of each communication is evaluated; end users have many of the same concerns regarding security as organizations and can use firewalls as well
35 Careers In IT Network Administrator
Manage a company’s LAN and WAN networks Maintain hardware and software Diagnose and repair problems Candidates usually have a bachelor’s degree in computer science and practical experience Annual salary is
typically between $43,000 and $68,000