Transcript Networks

Networks
Learning Objectives:
By the end of this lesson you should be able to:
Learning Objectives:
By the end of this lesson you should be able to:
• identify the advantages and disadvantages of using
networks (including the Internet);
Learning Objectives:
By the end of this lesson you should be able to:
• identify the advantages and disadvantages of using
networks (including the Internet);
• describe what is meant by the terms user ids and
passwords, stating their purpose and use;
What is a Network?
What is a Network?
• computers linked together
– to share resources
What is a Network?
• computers linked together
– to share resources
• linked computers are often called Workstations
What is a Network?
• computers linked together
– to share resources
• linked computers are often called Workstations
• most networks have a server
– which controls the operation of the network
What is a Network?
• computers linked together
– to share resources
• linked computers are often called Workstations
• most networks have a server
– which controls the operation of the network
What do we share?
What is a Network?
• computers linked together
– to share resources
• linked computers are often called Workstations
• most networks have a server
– which controls the operation of the network
What do we share?
• printers
What is a Network?
• computers linked together
– to share resources
• linked computers are often called Workstations
• most networks have a server
– which controls the operation of the network
What do we share?
• printers
• Internet connection
What is a Network?
• computers linked together
– to share resources
• linked computers are often called Workstations
• most networks have a server
– which controls the operation of the network
What do we share?
• printers
• Internet connection
• software
What is a Network?
• computers linked together
– to share resources
• linked computers are often called Workstations
• most networks have a server
– which controls the operation of the network
What do we share?
• printers
• Internet connection
• software
• data
What types of network are there?
• Local Area Network
– LAN
– workstations are close together
• in the same room, building, house, school site...
• Wide Area Network
– WAN
– workstations are distant
• branches of a bank, the Internet
Advantages of a network
Advantages of a network
• access your files from any workstation on the network.
Advantages of a network
• access your files from any workstation on the network.
• private areas on the network can be set up
– allows each user to store their personal files.
Advantages of a network
• access your files from any workstation on the network.
• private areas on the network can be set up
– allows each user to store their personal files.
• individual workstations do not need a printer,
– one high quality printer can now be shared by everyone
Advantages of a network
• access your files from any workstation on the network.
• private areas on the network can be set up
– allows each user to store their personal files.
• individual workstations do not need a printer,
– one high quality printer can now be shared by everyone
• users can communicate with others on the network
– by sending messages and sharing files.
Advantages of a network
• access your files from any workstation on the network.
• private areas on the network can be set up
– allows each user to store their personal files.
• individual workstations do not need a printer,
– one high quality printer can now be shared by everyone
• users can communicate with others on the network
– by sending messages and sharing files.
• data can be shared by all users at the same time.
– many people can use information at the same time.
– shopping, eBay, flight booking
Disadvantages of a network
Disadvantages of a network
• networks can be expensive to set up
– cables, network hardware, server, technicians
Disadvantages of a network
• networks can be expensive to set up
– cables, network hardware, server, technicians
• vulnerable to security problems
– hackers could read or damage crucial information
– viruses
Disadvantages of a network
• networks can be expensive to set up
– cables, network hardware, server, technicians
• vulnerable to security problems
– hackers could read or damage crucial information
– viruses
• if the main server breaks down, network is useless
– no-one can carry on working.
Disadvantages of a network
• networks can be expensive to set up
– cables, network hardware, server, technicians
• vulnerable to security problems
– hackers could read or damage crucial information
– viruses
• if the main server breaks down, network is useless
– no-one can carry on working.
• more users on the network = slower network speed
Network Security
Network Security
• networks are vulnerable to security problems
– because there are many computers connected together
Network Security
• networks are vulnerable to security problems
– because there are many computers connected together
• a lack of security could lead to:
– theft of data
– viruses
Network Security
• networks are vulnerable to security problems
– because there are many computers connected together
• a lack of security could lead to:
– theft of data
– viruses
• most networks require the user to “log on”
– requiring a User-ID and Password
– only authorised users are allowed access
Passwords
Passwords
• should be kept secret at all times
Passwords
• should be kept secret at all times
• should not be something that is easy to guess
– such as pet's name or favourite football team.
Passwords
• should be kept secret at all times
• should not be something that is easy to guess
– such as pet's name or favourite football team.
• should include text and numbers
Passwords
• should be kept secret at all times
• should not be something that is easy to guess
– such as pet's name or favourite football team.
• should include text and numbers
• should be a reasonable length
– e.g. over 6 characters
Passwords
• should be kept secret at all times
• should not be something that is easy to guess
– such as pet's name or favourite football team.
• should include text and numbers
• should be a reasonable length
– e.g. over 6 characters
• should be changed regularly