WGU D322 Section 4

PAN

Normally used for short-range communications, within a few feet, such as wireless headphones to a smartphone or a wireless mouse to a PC

LAN

Consist of a collection of computers in a single building or building complex. For example, the computers in a manufacturing building may be connected via a _________

WAN

Link systems over a greater distance, including machines on the opposite sides of the world

client/server model

A popular convention used for interprocess communication. The basic roles played by the processes are categorized as either a client making requests or a server satisfying client requests

Peer-to-peer (P2P)

Another model for interprocess communication. In this model, processers both request and provide service to each other. Instant messaging and interactive games played by users on multiple machines are both examples of _________

Distributed systems

Execute software as processes on more than one computer

Cluster computing

Uses many independent computers to provide computation or services comparable to those of a larger machine. Provides high availability as it is likely that at least one computer will be able to answer a request even when others are unavailable or broken down. In addition, can balance loads by automatically shifting requests among the members.

Grid computing

A type of distributed system that is more loosely coupled than clusters but still works together as a system to complete large tasks. Typically includes specialized software to make it easier to distribute the workload and data among the machines

Cloud computing

Provides large pools of shared computers that can be allocated to clients as needed. Allows users to collaborate or build web services without needing to know how many computers are working on the problem or where the relevant data is stored. Provides reasonable guarantees for reliability and scalability while raising concerns about security and privacy.

Transmission medium

Simply a component that carries data from one network device to another. There are two types: wired and wireless.

Network bandwidth

Typically measured in megabits per second (Mbps) and gigabits (Gbps) per second. (Note the distinction between Mbps and MB. One megabit is equivalent to 1,000 kilobits, whereas one megabyte is equivalent to 1,024 kilobytes.)

Coaxial cables

Have an outer plastic that is used in computer networks and to deliver cable TV services. First used commercially used in the 1940s, it is used for both baseband and broadband data communication services. Cable modems and televisions typically use _______

Baseband

A signal at a very narrow frequency range on which data or information is superimposed and then transmitted. Examples include Ethernet LANs and serial cables.

Broadband

Considered high-capacity transmission technologies that are used to transmit data, voice, and video across long distances and at high speeds. Examples include coaxial cable, fiber optic cable, and radio waves.

Fiber-optic cable

Uses the concept of reflection of light through a core made up of glass or plastic. The core is surrounded by a less dense glass or plastic covering called the cladding. _______ are able to transmit large volumes of data. Their bandwidth can provide up to 26,000 times the bandwidth of the twisted pair wires.

Repeaters

Extend the range of cabling types so connections can be made by increasing the strength of the network signal.

Bridges

Used to connect to different types of network and provide management of the message. For example, _______ can connect a twisted pair and coaxial network. _______ analyzes the network message and will only bridge the network if a message is addressed to a device on the other side.

Switches

Used on LANs to reduce network traffic by management of network messages. For example, on a 100-device network, a _______ would only send one message to the destination device. This management example would create 99% less traffic.

Routers

The device that makes the internet possible. Connected to your LAN acts as gateway to the internet. Manage network traffic by having a routing table of known devices. If a destination address is unknown, it will forward the message to another until the message reaches the correct address.

ICANN

Internet Corporation for Assigned Names and Numbers. A nonprofit organization that coordinates the internet's operations, awards blocks of consecutively numbered IP addresses to ISPs.

TLD

Top-Level Domain

hypertext transfer protocol (HTTP)

As web servers and browsers became more sophisticated, traditional networks became handled by web pages using the powerful _______

SMTP

Simple Mail Transfer Protocol

DNS

Domain Name System

POP3

Post Office Protocol version 3

IMAP

Internet Message Access Protocol

VoIP

Voice over Internet Protocol - used for voice communication over the Internet

CDNs

Content Delivery Networks

URL

Uniform Resource Locator - includes the protocol, domain, and all subdomains, as well as the resource path ID and name of the document. This information collectively indicates the location of the document on the server.

HTML

A standardized system for tagging text files to achieve font, color, graphic, and hyperlink effects on World Wide Web pages - focuses on appearance.

XML

Extensible Markup Language - emphasizes semantics.

Malware (malicious software)

Any software intentionally designed to cause damage to a computer, server, client, or computer network.

Virus

Software program that infects a computer by inserting itself into programs that already reside in the machine.

Worm

An autonomous program that forwards copies of itself to other machines in a network and could result in detriment of individual machines or the operations of the network.

Spyware

Resides on a computer, collecting information about the computer's activities and reporting back to the spyware's instigator. Passwords or credit card numbers can be exposed.

Phishing

Technique used to obtain private information by simply asking for it. The perpetrator sends emails posing as a legitimate business asking for information.

Denial of Service (DoS)

The process of overloading a computer with messages and results in suffocating the network resources.

Packet sniffing or Man-in-the-middle (MITM)

The attacker intercepts the data as it is traveling to or from the victim's device, including authentication credentials.

Brute force attack

This is where the attacker uses all possible combinations of characters to learn a user's password. There are multiple variations of this attack.

Dictionary attacks

Performed by the attacker by using an application and a large dictionary text file with just words. When the attacker runs the application, it tries identifying the password by trying hundreds or thousands of words per minute from that file.

Rainbow tables

Try to identify the hash value of the password, then convert it back to plain text.

Proxy server

Software that acts as an intermediary between a client and a server to shield the client from adverse actions of the server.

Network auditing software

Monitors network behaviors such as the origin and volume of traffic, looking for anomalies to proactively or reactively mitigate unwanted occurrences.

Antivirus software

Detects and removes known viruses from the network.

Encryption

Encodes information to keep it confidential even if the data is stolen.