Networks and Security Flashcards
How is Transmission media measured?
speed, mobility and reliability
What are some characteristics of Fibre Optic Cables?
Long distances, speed of light, no sharp corners, expensive, need specialists
to install
What are some characteristics of Twisted Pair Cables?
no more than 100-200m, cheap, easy to install
What are some characteristics of Radio Waves?
radial, broadcasts out from central point, can travel through objects
(includes wifi and Bluetooth)
What are some characteristics of Microwaves?
narrow line of sight (think laser beam), can’t travel through obstructions
(buildings, hills, people, fog). Need to move base if receiver not in range)
What are some characteristics of Satellite?
uses satellite technology
What are some characteristics of Infrared?
– much lower frequency to the others, very short distance, direct line of sight
required. Very outdated – only used now for remote controls (TV etc)
What are the Advantages and Disadvantages of Wired Transmission?
A: Cheap, Easy to set up, Security, Fast
D: Limited to data points installed, No portability
What are the Advantages and Disadvantages of Wired Transmission?
A: Mobile, Add nodes/devices easily, Cheaper in the long run, Can be used to attract customers
D: Expensive initial setup, Security, Slower, Limited range, slower the further away, Obstacles (walls, water, crowds…) hinder access
What are some examples of Wired Transmission?
Fibre Optic, Twisted Pair
What are some examples of Wireless Transmission?
Radio Waves, Microwave, Satellite, Infrared
What is a NOS?
Network Operating Software, oversees and runs the network, can be given the
task of prioritising access/putting requests into print queues etc
What is a Firewall?
A firewall is a system designed to prevent unauthorised access to or from a private network.
What is a Modem?
A modem is a device or program that enables a computer to transmit data.
What is a Router?
A Router is an electronic device that joins multiple computer networks together via either wired or wireless connections.
What is a Hub?
A Hub is a device that will send signals to all connected devices, only correct one will accept
signal… lots of clashes. NEVER RECOMMEND
What is a Switch?
A Switch is a device that will only send a signal to the correct device, not all of them like the ‘HUB’
What is a Node?
A network node is a connection point that can receive, create, store or send data along distributed network routes
What is a Server?
A server is a computer program or a device that provides functionality for other programs or devices.
What are examples of Deliberate Threats to a Network?
o Worm – self-replicating, no human intervention required to spread
o Trojan – hidden in another file (often in media, software)
o Spyware – malware (malicious software) that can key log, track activity etc
o Hackers
o Malicious employees
o Theft of computers/servers
What are examples of Accidental Threats to a Network?
o Technical Problems (disk failure, corruption)
o Power Issues (Blackout, Brownout, Power Surges -> can be resolved with a Uninterruptable power supply)
o Incompetent users (Accidental Deletion, Poor file management)
What are examples of Events-based Threats to a Network?
fire, flood, earthquake, dog chewing cables, a truck crashing through the back wall into the server
If Threats are evident, what will they impact?
Data integrity Data security (opens up to legal and company survival issues)
What are examples of Physical Security Controls?
o Equipment - includes zoned areas, barriers (eg locks), biometrics
o Procedures – backups, shredding documents, checking credentials
What are examples of Software Security Controls?
Username (for identification and hierarchical access) and password (secure)
o Access logs, audit trails
o Encryption
o Firewalls
o Protocols (Transport Layer Security (TLS), Secure Sockets Layer (SSL))
What is Security?
Security is making sure only authorised people to have access to files. In reference to File management, Hierarchical access is a good start. Ways to test:
o audit trail – records changes to software
o access log – records what users open, download, which sites they visit
What is Archiving?
Archiving is storing files in another location. This location is harder to get to and is not for everyday use items
What is Backing Up?
Backing up is creating other copies of data stored elsewhere in case something happens to the original data
What is Disposal?
Disposal is deleting the files permanently. This involves placing in the trash, emptying trash,
defragmenting the drive several times and using speciality rewriting software for top-secret files.
