Chapter 6 - Comouter Communication Flashcards
What is a node?
A device on a network
What is LAN?
Local area network
Confined to one site
Connected and maintained by an organisation
What is a WAN?
Wide area network which covers a large geographical area
They often connect LANs together
They allow a business to function from any location
What are cables used for?
To connect different devices in LANs
Two different types of wires?
Copper cable/UTP: light and flexible, easy to install
Fibre optic cable: for longer distances, transmits signals using waves, cheaper
What is a hub?
Hardware devices which connect many network devices together making them into a network segment.
What are switches?
They connect network segments or devices
They also act as bridges, which connect more than one network - allowing them to function as one network
Difference between Hun and switches?
A switch only transmits a message to the device intended instead of all connections.
Hubs have a number of input and output ports which are all connected, a signal arriving from one is transmitted to all others
What is an NIC?
Network interface card Generates and receives suitable electrical signals Carries out simple addressing Built into the motherboard Acts as a LAN adapter
What is a MAC address?
Every NIC has a unique number stored in ROM, this is called its MAC address
MAC addresses allow each node on a network to be identified
What is a wireless access point?
They allow connection to a LAN without the need for physical cables using standards such as WiFi.
What are access points often connected to?
A router
Pros of access points
Save money and effort because new bodes can be added without the need for more cables
How are Security risks of access points dealt with?
Encryption
Hiding their broadcast identities
Allowing access to only certain MAC addresses
What is a router?
Receives day in the form of packets and forwards them to their destination which is often another router
Used to direct traffic in the internet but also to connect small individual computers to the Internet service provider
Advantages of LANs?
Central data storage makes data sharing possible and convenient and makes backups easier
Computers in LAN are easily upgraded or reconfigured centrally
Security policies are centrally administered
What is a client server network?
One server(computer set up to handle network functions) produces services to many client machines where the users work.
What is a peer to peer network?
All computers are equal
Each computer serves the needs of the user as well as carrying out networking functions
What is a topology?
Layout of network components
What is a bus topology?
Computers and other devices are attached to a back bone. A terminator is attached at each end to prevent reflection of signals, signals travel in either direction.
Pros of bus
Easy to set up
Cheap
Cons of bus
Problem with backbone can bring the whole network down
Many data collisions slow the network down
What is a star topology?
Client machines are connected to a central switch which is usually in turn connected to one or more servers. Signals travel in either directions
Pros of star?
Robust - problem with a connection do not affect the whole network
Fewer data collisions so faster than bus
