Computer Networks

flashcards abo8ut computer networks for OCR GCSE

What is a network

2 or more computers connected together so the may communicate with each other

What is an advantage of networking ( 4 things)

file sharing

hardware sharing

communication

roaming access

What is roaming access in computer networks?

A user can login to any computer on the network and access their files

Advantages of networking (4 THINGS)

Centralised maintenance and updates

centralised security

monitoring users

managing levels of access

disadvantages of networking

high set up cost

need for management

easy spread of malware

hacking risk

What does LAN stand for

Local Area Network

Features of LAN (3 points and an example)

Operates in a small geographical area

Privately owned by owner of that area

Can be wired or wireless

house network

What does WAN stand for

Wide Area Network

Features of a WAN (2 points and an example)

Connect computers over a large distance

third party hardware and cabling

the internet

What is bandwidth

How much data can be transferred at once

What can affect performance of a network

Bandwith of transmission medium

number of devices

type of network traffic

network latency

number of transmission errors

what does WAP stand for

Wireless Access Point

What does WAP do

Connects to hub / switch and lets devices connect to a network wirelessly with WiFi

What do WAPs broadcast

SSID

What is an SSID

a network name

What is the point of the SSID

wireless networks know which network to join

What is it important for WAPs to use and why

encryption and authorisation so people don’t take advantage of the network

What does a router do?

a piece of hardware that connects networks together

What do routers do?

Look at IP of a packet to see if it is going to right place

If it is not, it is sent to the right place

IP stands for?

Internet Protocol

What does Switch do?

Connects devices on a network together

How does switch work?

When data sent on network it contains MAC address of sender and recipient.

Sends the data to the right address after

What does MAC address stand for

Media Access Control

What is the MAC address

an address unique to the NIC of each computer and helps identify them on a network

What is an NIC

Network Interface card

What does NIC do?

Allows device to connect to a network

What is a hub

lets device connect with wires to a network

STAR network

each device connected to central switch

Switch uses MAC address to direct data

Good security and performance

Advantages of STAR

Reliable

few data collisions so high performance

Disadvantages of STAR

cable required for each computer, so expensive

switch needed to direct transmissions, central failure point