Networks

Networks

1. Basic elements of an ICT network

   • NIC (Network Interface Card,Allows a connection between the computer and the internet cabling).
   • Hub (Join computers in a network together)
   • Switch (Similar to hubs, but also have the ability to analyse packets of data to send them to the correct destination)
   • Router (Joins several wires/wireless networks together)
   • Network software (For large client severs, special software is needed)
   • Data transfer media
     • Metal wires (High transmission but can be expensive)
     • Fibre optic (Data is encoded and transmitted fast but is expensive)
     • Wireless
   • Wireless
     • The router is connected to the Internet
     • Router receives data from the Internet
     • It transmits the data as a radio signal using an antenna
     • Computers wireless adapter picks up the signal and turns the signal into something the computer can understand.
       • Wireless network
     • Advantages
       • Inexpensive LANS to be set up without cables
       • Working anywhere there is a signal
       • Old listed buildings
       • Global set of standards around the world.
     • Disadvantages
       • Power consumption is high
       • Health problems
       • Security problems
       • Limited range
       • Interference with overlapping signals.

2. Networks and stand alone computers

   • Standalone (computer on its own without any connection to other computers)
     • Advantage
       • Cheaper hardware and software
       • Less IT knowledge needed
       • Fewer problems with viruses
       • Not as hardware dependant.
     • Disadvantage
       • Unable to transfer files with ease
       • Hard to keep data up to date it two people are working on the same document
       • Software has to be installed on all computers.
       • Backs up taken by individual users.
   • Network (two or more computers are connected in some way)
     • Advantage
       • Central pool of data/documents
       • Ability to share hardware
       • Ability to share software
       • Remote management
       • Improved security
       • Easier to back up
       • Improved communication.
     • Disadvantage
       • Initial cost of network
         • Lack of access when server is down
       • Technical knowledge is needed.

3. LAN and WANs

   • LAN (Local Area Network)
     • confined to one building or site
     • Ownership of the communications equipment
   • – WAN(WideAreaNetwork)
     • spread over a wide geographical area
     • Third party telecommunications equipment is used.

4. The Internet, intranet and extranet

   • Internet
     • Huge group of networks joined together.
     • WWW is the means of accessing information on the internet.
   • Intranets
     • Private internal network allowing the sharing of organisational information.
   • Extranets
     • Internal and external network which is restricted to employees, customers, suppliers and other partners of the organisation, accessed via a username and password.
   • Internet
     • Advantages
       • Methods of cheap communication, i.e. email
       • Video such as TV programs
       • Listen to the radio
       • Run/download educational games
       • Send and receive files
       • Research information
       • Communicate
       • Share resources
       • Shop on-line
     • Disadvantages
       • Access inappropriate material
       • Children inadvertently forming ‘friendships’ with strangers
       • Cyber bullying
       • Advertisement pressures.
   • Communications
     • Instant messaging (send and receive messages almost instantly)
     • Webcam services (See and hear who you are talking to)
     • Cheap phone calls (Internet phone calls)
       • Chatrooms (Chat with friends)
     • Text messaging (Send and receive messages via phones)
     • Email (Messages sent)
   • FTP(File transfer protocol)
     • Method for exchanging files over the internet
   • Newsgroups
     • A discussion where people are able to post and leave comments
   • On-line shopping
     • Purchase or sell items online
   • On-line databases
     • Companies store information in a database, i.e. holiday information
   • Search engine
     • A way of finding information on the Internet usinga search criteria.

5. Emails

   • Search (Keyword search to find an email)
   • Reply Read an email and respond to it)
   • Forward (Read an email and pass it on to someone)
   • Address book (Store a list of email contacts)
   • Groups (Lists of people with their email address)
   • Attachments (Attach pictures, documents, etc to an email)
   • Voice Mailboxes (Voice mail is left which can be played back at a later time).
   • Advantages
     • Virtually instantaneous
     • No need for familiarity of letter
     • Easily attach a copy of senders message with reply
     • Virtually free (Except for initial cost and internet charge)
     • Accessed using a large number of devices
     • More environmentally friendly.
   • Disadvantages
     • Not everyone has email
     • May make users more causal about their approach to work
     • Junk mail
     • Security aspects.