TOPIC 3 - Networking Flashcards
what is a computer network?
two or more computers connected together so that they can share resources
how does a firewall block unauthorized access?
Firewall keeps track which websites you have contacted recently and are waiting for a reply. You grant outside sites permission to push data on your device
what would a network for a large company include?
Internet Public telephone network Internal wired network Internal wireless network Cell phone network Video conferencing system Extranet: a private network that partenrts ,suppliers and vendors can access
what is circuit switching?
a path using wires connecting the source and the destination
what is packet switching?
Data is broken down into parts (called packets) roughly 1 KB in size
Packets are sent from the source to the desrtination (possibly along different network paths)
Packets are reassembled in their original order once they reached their destination
what is a key advantage of packet switching
only use the network when you have information to send -> More people can share the network
name 5 characteristics of networks
topology, geo scale, protocol, transmission media, services
explain typology and the common ones
how are the nodes connected to each other
Most common: star (most popular), bus, ring (rare)
explain the 5 popular geographic scales
NFC: mobile payment up to 4cm
PAN: bluetooth connecting a laptop to mouse (Personal area network, up to 10 meters)
LAN: within a small building or single floor (Local area network)
WLAN: wireless local network
WAN: wide area network: typically means internet or networks spanning regions or countries
what is a network protocol?
A network protocol is a set of rules governing how data is exchanged in a network
what is internet protocol suite
standard for most networks including the internet
what are the 2 core protocols?
transmission control protocol and internet protocol
TCP/IP are part of a 4 layer protocol suite. Name the layers
application, transport, internet, network
network breaks up into data link and physical
Explain the application layer and give an example
example: HTTP
Defines protocols for applications to exchange data
Send the data (webpage) to the transport layer to be transported
Explain the transport layer and give an example
example: TCP
It sets up and manages the connection with the destination
It breaks up the data into packets at the source and reassembles them at the destination
Explain the internet layer and give an example
example: IP
It addresses and routes a packet through the network
It gets the packet from a source to a destination based only on its address
Explain the data link layer
transporting a packet fromone router tothe next
turns 1s and 0s into packets and vice versa
explain the physical layer
looks at transporting the packets on some medium (ie. wires).
name 4 common physical transmission media
Twisted pair (of wires)
Coaxial cable
Fiber optic cable
Wireless Transmission
how do you characterize network performance?
bandwidth (number of bits transmitted per second)
larger bandwidth = faster = more data transfered
responsiveness is measured through latency -> how long it takes to receive the first byte of data
name 5 types of wireless communication
bluetooth, wifi, wimax, 3G/4G/5G, cell towers
what network is bluetooth used on and give example
used for PAN
examples: headset, mouse for computer
what network is Wifi used on and give example
WLAN and within office or home
explain wimax
Secture remote wireless access for longer distances -> up to 50 km
Based on microwaves
The path between the base station and the remote tower must be a direct path with no trees, buildings, or hills in the way
