Paper 1 Flashcards
Mistakes (24 cards)
What does the CU do?
Sends electrical signals to control the flow/movement of data(instructions) within the CPU
Controls F-E cycles (!!)
What effects the performance of a network?
bandwidth
number of devices connected
transmission medium
type/amount of data transferred
distance to travel/signal strength
What is bandwidth?
theoretical (!!) maximum amount of data a communication channel can carry at one time
How does bandwidth affect network performance?
more/less data can be transferred at the same time
How does number of devices on a network affect performance?
bandwidth shared/ split across all devices
less bandwidth for each device
less data can be sent at once/same time
more data is being transmitted at one time - increased collisions to occur
Characteristics of Ipv4 addresses
made of 4 group of digits
group has denary values from 0 to 225
group of digits are separated by a full stop (.)
What is a data packet?
broken down parts of a file
What is an embedded system?
system within a system that has a specific function
Why are data packets used?
(unlike larger files) they can be transferred through a network quickly
What is packet switching?
data packets are directed by routers across a network and may split up to take alternative pathways/routes/network paths
once arrived at destination, data is reassembled back into original file
What does a data packet contain?
Header: Ip address of source/device sent from and destination/device sent to, protocol, packet number
Payload: actual data
Trailer: checksum (calculate if any errors/corruption has occurred during transmission)
Why would a data packet contain Ip address of device it was sent from?
In case packet is lost during transmission and has to be resent
How are data packets sent and received?
Sent sequentially but travels on different network pathways so may be received unordered.
Uses the packet number in header to reorder them
What is network topology?
layout of computer systems on a network
Why is ethernet a standard?
allows compatibility with other devices
used in many/all devices
is a proven/reliable connection
Where is a website hosted?
on a web server
What does a user enter into a web browser?
Uniform Resource Locator (URL)
easier to remember
What does a router do?
Receives packets
Assigns Ip addresses to nodes/devices
Forwards/Sends/Transmits data packets
Identifies most efficient path to destination
Why would encryption be used?
Data won’t be understood if it is intercepted (will be meaningless)
Only authorised users can access confidential material / Protect confidential data
What is a wireless access point?
can be built in/separate
connects wireless and wired networks
allows wifi enabled devices to connect (wireless) to a network (wired)
creates wireless LAN
What is a switch
connects devices on a network (LAN)
messages/data to specific, intended device (using the MAC address of all devices on LAN)
What is the difference between a hub and switch?
Hub sends a copy of data to all devices on network, switch uses MAC address to send to a specific device
What is a network interface card?
Allows device to connect to a network (internal device- embedded onto motherboard)
Contains the MAC device which is used to send/ receive data (coverts signals and digital data)
What are the characteristics of a MAC address?
48 bits long- has hexadecimal
separated by colon (:)
