Networks Flashcards
What is a network
A collection of computers that are connected by some sort of communication media
What does a network allow users to do (5)
Share hardware Share software Share data Share information Communicate
What are the 7 reasons for having a network
Fast, efficient communication (E-mails, chats, video conferencing)
Sharing of hardware resources (Printers, scanners, DVD Players)
Centralisation of data (Files on a central computer)
Transfer of files
Leisure (LAN Parties)
Increased control and security (Centrally stored on 1 computer - backups and kept secure)
Flexible access (Can access information from any computer)
What are the 5 disadvantages of having a network
Higher level of expertise to manage a network
High level of security needs to be set up
Malware can spread quickly
If a network develops a problem, potentially no users can work
A central fault in the network can cause a loss of data
What are the 5 types of hardware required for a network
Computers and Peripherals Network interface controller Switch Communication media - Wired and Wireless Network Operating System
What does a network interface controller do
It links the network cable to the computer and allows communication between the computer and the network
What is a switch
A hardware device used to connect computers on a network so that communication can occur. It sends data from one computer to the specific computer that it must be sent to
What are the 2 types of Cables
Unshielded Twisted Pair (UTP)
Fibre Optic Cables
Describe an Unshielded Twisted Pair of cables
One or more pairs of copper wires twisted around each other. Unshielded refers to the fact that the wires are not covered in a foil insulating layer
Describe fibre optic cables
Many thin strands of glass or plastic surrounded by cladding and then covered by a final protective outer cover. Uses light beams rather than electrical signals. The presence of a pulse of light represents a 1 and no light represents a 0
Name 4 characteristics of Fibre Optic Cables
Thin and lightweight
Relatively complex to install and configure
Supports very high transmission rates
Network interfaces, cables and other devices that are used together with fibre optics are relatively expensive
What are the 4 weaknesses of communication media
Attenuation
Eavesdropping
Crosstalk
Electromagnetic interference
Describe Attenuation
Loss of signal strength over a distance
Which cable is most susceptible to attenuation and which has much lower attenuation
UTP is most susceptible
Fibre has much lower attenuation
Describe Eavesdropping
Eavesdropping is related to electromagnetic interference. It is possible for someone to detect a signal on a cable without piercing the cable
Which cable is susceptible to eavesdropping and which cable isn’t
UTP is sensitive to eavesdropping
Fibre is immune to eavesdropping
What is crosstalk
Two wires that are close to one another can interfere with transmission and create crosstalk
What is electromagnetic interference
An electronic signal that interferes with normal network transmission. Sources include engines, machinery, lights
What cable is sensitive to EMI and what cable is not
UTP is sensitive to EMI
Fibre is not affected by EMI
What is a network operating system
Software that controls all the communication in a network as well as the security on a network
What is a LAN
A network connecting computers in a small area.
How are computers connected within a LAN
Either using cables or wirelessly
What are 4 advantages of a Wireless LAN
Easier to add or move computers as the network points aren’t fixed
Easier to provide network connectivity in areas where it is difficult to lay a cable
Installation is far easier than with a cabled LAN
Adds mobility for laptop users
What are 3 disadvantages of a WLAN
Security can be compromised
Performance can decrease as the number of computers connected increases
Signal could get lost due to electronic or electrical interference
What is a WAN
A network spread over a wide geographical area
What is an intranet
An organisation’s private network consisting of web pages relating to the organisation’s business
What is an extranet
An intranet that has provided access to other users outside the organisation
What are the 3 roles of computers within a LAN
Clients
Servers
Peers
What are Clients
Computers that use but do not provide network resources
What are servers
Computers that only provide network resources - Have better hardware specifications such as more memory and larger hard drives
What are the 3 types of servers other than file servers
E-Mail servers
Internet or proxy servers
Print servers
What are the 3 functions of a file server
Manage data on the server’s hard drives
Control access to its services by other PCs in the network
Provide users with access to the files stored on it
What are Peers
Computers that both use and provide network resources
What is the difference between a Peer-To-Peer LAN and Client-Server LAN
A Peer-To-Peer LAN shares resources among workstations without a dedicated server.
A Client-Server LAN has client PCs which connect to one main server
What are 3 things to keep in mind when creating a password
At least 8 characters long - the longer the better
Contain a mixture of upper and lowercase letters, numbers and special characters
Do not use your name or anything that is easy to guess
