Networks

Am I hooked up?

What is a network?

A network is a group of 2 or more computers that are linked together either by wires or by a wireless means.

In order to network computers you require:

network hardware such as a network interface card

network software connecting devices such as hubs, routers,

etc. communication lines such as cable,

wireless capacity or phone line

Sizes of networks

• A local area network is a network that connects a few computers in a building or in close proximity. – A school network is an example of a

LAN.• A wide area network (WAN) is a

network that connects 2 or more LANs.

• WANs often span across a large area such as a country, a continent or even the world. – The Internet is an example of a

WAN.

Sizes of networks

Client/server networks• In a client/server network, a

server (or central computer) has a large disk for storage.

• Computers connected to the server share processing and storage functions with the server.

• A client (or user PC) can access files on the server but not necessarily other user files.

• A client/server network generally requires a login to access the network.

Advantages of a network

A network allows users to:• Communicate• Share Resources

– printer– application software

• exchange information• store data

Storage of data

• Files stored on a network can be backed up automatically.

• Network storage of files allows for a large storage capacity and the ability to access files from remote locations.

Disadvantages

• the cost to setup a network• the administration costs to

maintain and manage the network

• viruses can spread quickly across a network

• loss of privacy

ISP – Internet Service Providers

- a company that provides access to the Internet.

There are many ways to connect to the Internet: Phone Line Cable Satellite Wireless DSL

ISP – Internet Service Providers

Dial-up -Dial-up modems use the copper line from your home to the Central Office to transmit analog signals. Maximum speed is 56 kbps.

ISP – Internet Service Providers

Cable - Cable technologies use existing cable TV infrastructure (network) that your cable company uses for TV signals, to transmit data to and from the Internet.

ISP – Internet Service Providers

Satellite - An internet connection provided by satellite in orbit around the earth. Satellite internet technology has advanced in leaps and bounds over the years. Where you used to need a phone line for “half” of your internet connection, most satellite internet services is now bi-directional (data is sent and received via satellite).

ISP – Internet Service Providers

Wireless -It is possible to get Internet access via wireless options; think of a cordless phone or a cell phone. It works the same way and is considered high speed or broadband Internet access.

ISP – Internet Service Providers

DSL -Short for Digital Subscriber Line, DSL technologies use sophisticated modulation schemes to send data over the copper wire used for your phone connection and is considered high speed or broadband Internet access.

ISP – Internet Service Providers

Kilobit (Kb) - 1,024 bits for technical purposes, transfer rates are measured in kilobits per second, abbreviated as Kbps, and count a kilo as 1000 bits. Megabits per second (Mbps) more common today.

ISP – Internet Service Providers

Footnotes

Woman. Hassle Free Clip Art. Viewed March 3, 2006. <http://www.hasslefreeclipart.com/clipart_compusers/page1.html> Little_baldguy. Hassle Free Clip Art. Viewed March 3, 2006. <http://www.hasslefreeclipart.com/clipart_compusers/page1.html> Nerd. Hassle Free Clip Art. Viewed March 3, 2006. <http://www.hasslefreeclipart.com/clipart_compusers/page1.html> Stressed_out. Hassle Free Clip Art. Viewed March 3, 2006. <http://www.hasslefreeclipart.com/clipart_compusers/page1.html> Buculei, Nicu. Open Clip Art. Viewed March 3, 2006. < http://www.openclipart.org/cgi-bin/navigate/computer/hardware> Fitzsimon, Andy. Computer. Open Clip Art. Viewed March 3, 2006. <http://www.openclipart.org/cgi-bin/navigate/computer/hardware?page=2>

Networks