Chapter 7: System Architecture

Question 1

Client-based systems

Answer 1

execute all core functions on the user’s device and don’t require network connectivity

Question 2

Server-based systems

Answer 2

require a client make requests from a server across a network connection

Question 3

Transactions

Answer 3

sequences of actions required to properly change the state of a database

Question 4

Properties of Database transactions

Answer 4

atomic, consistent, isolated, durable (ACID)

Question 5

Aggregation

Answer 5

combining info from separate sources; security problem when it allows unauthorized individuals to piece together sensitive info

Question 6

Inference

Answer 6

deducing a whole set of info from a subset of its aggregated components; security problem when it allows unauthorized individuals to infer sensitive info

Question 7

HPC

Answer 7

High-performance computing; aggregation of computing power which exceed capabilities of general-purpose computers for the specific purpose of solving large problems

Question 8

ICS

Answer 8

Industrial control systems; IT specifically designed to control physical devices in industrial processes

Question 9

Embedded system

Answer 9

cyber-physical system; computers and physical devices collaborate via the exchange of inputs and outputs to accomplish a task or objective

Question 10

Two main types of ICS

Answer 10

DCS and SCADA

Question 11

DCS

Answer 11

distributed control systems; use PLC; control devices within fairly close proximity

Question 12

SCADA

Answer 12

supervisory control and data acquisition system; uses RTUs or PLCs; control large-scale physical processes involving nodes separated by significant distances

Question 13

Difference between DCS and SCADA

Answer 13

DCS controls local processes; SCADA used to control things remotely

Question 14

ICS connectivity

Answer 14

should always be logically or physically isolated from public networks

Question 15

Virtualized system

Answer 15

exist in software-simulated environments

Question 16

VM

Answer 16

virtual machine; computing hardware has been virtualized for the operating systems running in them

Question 17

Containers

Answer 17

systems in which the operating systems have been virtualized for the applications running in them; very common for containers and microservices to be used together; houst microservices; run in sandboxes

Question 18

Microservices

Answer 18

software architectures; features are divided into multiple separate components which work together in a distributed manner across a network

Question 19

serverless architecture

Answer 19

services offered to end user can be performed without a requirement to set up any dedicated server infrastructure

Question 20

Cloud computing

Answer 20

use of shared, remote computing devices for the purpose of providing improved efficiencies, performance, reliability, scalability, and security

Question 21

SaaS

Answer 21

Software as a Service; cloud computing model which provides users access to specific application that executes in the service provider’s environment

Question 22

PaaS

Answer 22

Platform as a Service; cloud computing model which provides users access to a computing platform but not to the operating system or to the virtual machine on which it runs

Question 23

IaaS

Answer 23

Infrastructure as a Service; cloud computing model which provides users unfettered access to a cloud device, like an instance of a server, which includes both the operating system and virtual machine on which it runs

Question 24

Embedded system

Answer 24

self-contained, ruggedized, computer system with its own processor, memory, and input/output devices designed for a very specific purpose

Question 25

IoT

Answer 25

Internet of Things; global network of connected embedded systems

Question 26

distributed system

Answer 26

system in which multiple computing nodes, interconnected by a network, exchange info for the accomplishment of collective tasks

Question 27

Edge computing

Answer 27

a distributed system in which some computational and data storage assets are deployed close to where they are needed in order to reduce latency and network traffic

Question 28

PLC

Answer 28

programmable logic controller

Question 29

RTU

Answer 29

remote terminal unit

Question 30

Hypervisors

Answer 30

used to virtualize the hardware on which virtual machines run; provide visibility and logging as a secondary function

Question 31

Virtualizing the operating system

Answer 31

Containers

Question 32

Issues when securing embedded systems

Answer 32

use of proprietary code, devices that "phone home", ability to update and patch them securely

Question 33

Microcontrollers

Answer 33

specialized devices with CPU, memory, and peripheral control interfaces; used to build embedded systems

Question 34

Three layers of edge computing

Answer 34

End devices, edge devices, and cloud infrastructure