Basic Knowledge
1. Software as a Service (SaaS):
o What it is: SaaS delivers software applications over the internet, allowing users
to access them via a web browser.
o Examples: Google Docs, Office 365.
o Use case: Ideal for users who want ready-to-use software without worrying about
installation or maintenance. It's like renting software on the web.
2. Infrastructure as a Service (IaaS):
o What it is: IaaS provides virtualized computing resources, including servers,
storage, and networking, as a service.
o Use case: Businesses can outsource their hardware needs, scaling resources up or
down as required, and paying only for what they use. It's like renting virtual
servers.
3. Platform as a Service (PaaS):
o What it is: PaaS offers a complete development and deployment environment for
building and running applications.
o Use case: Developers use PaaS to create, test, and deploy software without
worrying about the underlying infrastructure. It's like renting a pre-configured
development environment.
4. Desktop as a Service (DaaS):
o What it is: DaaS delivers virtual desktops over the internet, allowing users to
access a complete desktop environment from a remote server.
o Use case: Enterprises use DaaS to provide employees with secure, scalable, and
easily managed desktops. It's like having your computer in the cloud.
SaaS offers ready-to-use software applications,
IaaS provides virtualized hardware resources,
PaaS offers development and deployment platforms,
DaaS delivers virtual desktop environments.
Desktop as a Service (DaaS) is a cloud computing offering where a service provider delivers
virtual desktops to end-users over the Internet, licensed with a per-user subscription.
Syslog Server:
o
What it is: A Syslog server is a system that collects and stores log messages
generated by various devices and applications.
o Purpose: It helps centralize log data from different sources, making it easier for
analysts to review and correlate logs for security and troubleshooting purposes.
o Example: Syslog messages can come from devices like Cisco routers, switches,
servers, and workstations, and are collected in a central database for analysis.
2. Proxy Server:
o What it is: A proxy server is an intermediary server application that sits between
a client and a server, forwarding client requests to the server and returning server
responses to the client.
o Purpose: It can be used for various purposes, including improving security,
caching content for faster access, and controlling access to specific resources.
o Example: In a corporate network, a proxy server can be used to filter and control
internet access for employees, enhancing security and performance.
3. Domain Name System (DNS):
o What it is: DNS is a hierarchical and decentralized naming system used to
translate human-friendly domain names (e.g., www.example.com) into IP
addresses (e.g., 192.168.1.1).
o Purpose: DNS is essential for locating resources on the internet and private
networks. It helps users access websites and services using easy-to-remember
domain names.
o Port: DNS typically uses port 53 for communication.
4. Dynamic Host Configuration Protocol (DHCP):
o What it is: DHCP is a network management protocol used on IP networks to
automatically assign IP addresses and other network configuration parameters to
devices.
o Purpose: DHCP simplifies network administration by dynamically allocating IP
addresses to devices when they connect to the network.
o Port: DHCP typically uses port 67 for server communication and port 68 for
client communication.
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a Syslog server collects and centralizes log data,
a proxy server acts as an intermediary for client-server communication,
DNS translates domain names into IP addresses,
DHCP automates the assignment of IP addresses to devices on a network.
1. Cable Modem:
o What it is: A cable modem is a device that connects to cable television
infrastructure to provide high-speed internet access.
o Purpose: It allows users to access broadband internet services over cable
networks, which use a combination of fiber optics and coaxial cables for data
transmission.
2. DSL (Digital Subscriber Line):
o What it is: DSL is a technology that uses ordinary copper telephone lines to
transmit high-bit-rate multimedia traffic.
o Purpose: It enables telecommunications companies to provide high-speed
internet access by connecting homes to local switching centers using existing
phone lines and DSLAMs (DSL Access Multiplexers) to multiplex connections.
3. Optical Network Terminal (ONT):
o What it is: An ONT is a device that converts optical signals from fiber optic
cables into electrical signals for various types of wiring, like Ethernet and phone
lines.
o Purpose: ONTs are commonly used in Fiber to the Home (FTTH) installations,
allowing users to connect their devices to high-speed fiber optic networks.
4. Software-Defined Networking (SDN):
o What it is: SDN is an approach to network management that allows for dynamic
and programmable configuration of network resources.
o Purpose: SDN enhances network performance and monitoring by making
network configuration more flexible and responsive. It uses APIs and compatible
hardware to program network appliances and systems, making it similar to cloud
computing in terms of flexibility and control.
a cable modem provides high-speed internet over cable networks,
DSL uses telephone lines for high-speed data transmission,
an ONT converts optical signals for various wiring types,
SDN enables flexible and programmable network management for improved performance and
monitoring.
1. Community Cloud:
o What it is: A community cloud is a shared computing infrastructure used by
multiple organizations with common interests or concerns.
o Key Points: It can be managed and hosted either internally or by a third party. It's
like a hybrid of a private cloud, where select organizations collaborate on a shared
platform.
2. Public Cloud:
o What it is: A public cloud offers services provided by third-party providers over
the internet, available to anyone.
o Key Points: These services can be free or on-demand, allowing users to pay only
for what they use. It's like a public utility where resources are accessible to the
general public.
3. Private Cloud:
o What it is: A private cloud provides services over either the internet or an
internal network, but it's restricted to select users within an organization.
o Key Points: It's like having a cloud exclusively for a specific company or entity,
offering more control and privacy.
4. Hybrid Cloud:
o What it is: A hybrid cloud is a mix of on-premises, private cloud, and public
cloud services, with the ability to orchestrate between them.
o Key Points: This setup enables flexibility by allowing data and applications to
move between different environments. It's like having a combination of your
private and public clouds, connected seamlessly.
a community cloud involves multiple organizations sharing infrastructure,
a public cloud offers services to the general public,
a private cloud serves a specific organization or users,
a hybrid cloud combines various cloud types with orchestration for flexibility and scalability.
HyperThreading (HT):
o
What it is: HyperThreading is an Intel CPU technology that exposes multiple
logical processors to the operating system, providing performance benefits.
o Key Points: It allows a single physical core to behave like multiple logical cores,
which is especially useful in virtualized environments, enabling better
multitasking and performance.
2. 32-bit CPU:
o What it is: A 32-bit CPU is a hardware component found in low-end notebooks
or thin clients.
o Key Points: It's a type of central processing unit designed for older systems and
has limitations compared to modern 64-bit CPUs.
3. Dedicated GPU (Graphics Processing Unit):
o What it is: A dedicated GPU is a separate graphics card used for rendering
graphics in computers.
o Key Points: While important for graphics-intensive tasks, it doesn't directly help
with running multiple virtual machines. It primarily enhances graphics
performance.
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HyperThreading improves CPU performance by exposing multiple logical processors to
the OS.
a 32-bit CPU is older and found in low-end devices.
A dedicated GPU is used for graphics processing and doesn't directly assist with
runningvirtual machines.
What it is: USB is a common type of connection interface used in desktops and laptops for
connecting various devices.
USB has different types of connectors, such as Type A (host), Type B, Mini-Type B, and MicroType B (device).
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1. It allows for easy plug-and-play connections, meaning you can connect
and disconnect devices without turning off your computer.
2. USB ports can provide power to connected devices.
USB Versions:
o USB 1.1: Supports data rates up to 12 Mbps.
o USB 2.0: Supports data rates up to 480 Mbps and is backward compatible with
USB 1.1 devices.
o USB 3.0 and 3.1: Define data rates of 5 Gbps (SuperSpeed) and 10 Gbps
(SuperSpeed+).
Backward Compatibility:
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USB 2.0 is backward compatible with USB 1.1 devices, but they will run at the
slower USB 1.1 speed.
Power Delivery: USB ports can provide power to connected devices.
o USB 2.0 can deliver up to 2.5 watts (W) of power.
o USB 3.0 and 3.1 can deliver up to 4.5 W of power, making them suitable for
powering and charging a wider range of devices.
Dynamic IP Address:
o Usage: Best for client workstations and devices.
o Configuration: DHCP server assigns the IP address, subnet mask, gateway, and
DNS server's IP address.
o Benefits: Easy to configure, reduces human errors during setup.
Static IP Address:
o Usage: Ideal for servers.
o Configuration: Manually set the IP address, subnet mask, gateway, and DNS
server's IP address.
o Benefits: Ensures servers are easy to locate, access, and manage on the network.
DHCP (Dynamic Host Configuration Protocol):
o Usage: Enables automatic assignment of dynamic IP addresses.
o Configuration: DHCP server provides IP, subnet mask, gateway, and DNS
server details to clients.
o Purpose: Simplifies network management and reduces manual configuration
efforts.
Automatic Private IP Addressing (APIPA):
o Usage: When no DHCP server is available, typically in a small local network.
o Configuration: Computers automatically assign themselves an APIPA address.
o Benefits: Allows devices to communicate within the same network, but not with
other networks or devices with valid DHCP leases.
o Alias: Also known as a link-local address.
Dynamic IP addresses are convenient for client devices, while static IP addresses are best
for servers.
DHCP simplifies IP address management,
APIPA automatically addresses local networks when no DHCP server is present.
2.4 GHz Frequency:
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Wavelength: It has a longer wavelength compared to 5.0 GHz.
Propagation: Better at propagating through solid surfaces like walls.
Range: Can cover a longer range using the same power output as 5.0 GHz.
Data Rates: Supports lower data rates due to higher levels of congestion and
interference.
5.0 GHz Frequency:
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Wavelength: Has a shorter wavelength than 2.4 GHz.
Propagation: Less effective at penetrating solid surfaces.
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Range: Offers a shorter range compared to 2.4 GHz with the same power output.
Data Rates: Supports higher data rates due to lower congestion and interference, thanks
to more individual channels.
Inverter: 逆变器：
o
Function: It's a small board in the laptop's display assembly that provides power
to the backlight source of the LCD screen.
o Issue: If the inverter is faulty, the display becomes too dim, requiring an external
light source to see it clearly.
2. Digitizer:
o Function: It's a touch-sensitive glass panel on a touchscreen assembly that
converts touch actions into digital signals for input.
o Purpose: Enables users to interact with the screen through touch, making it useful
for various applications.
3. Liquid Crystal Display (LCD) Panel:
o Function: It's a display technology that creates images by controlling liquid
crystal cells with electrical charges.
o Backlight: Typically illuminated by a cold cathode fluorescent (CCFL) bulb,
providing uniform LCD lighting.
4. Graphics Processing Unit (GPU):
o Function: A microprocessor found in dedicated video adapter cards or integrated
within the CPU to handle complex mathematical calculations required for
rendering immersive and 3D graphics.
o Purpose: Enhances graphics performance for tasks like gaming, video editing,
and 3D modeling.
 Intrusion Prevention System (IPS): detects and blocks network threats, a proxy server acts as
an intermediary for resource requests
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Function: It's a network security tool that identifies and prevents known threats by
continuously monitoring network traffic.
Key Feature: Can actively block malicious network traffic, providing real-time
protection compared to an Intrusion Detection System (IDS), which only logs potential
threats.
 Proxy Server:
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Function: A server application that acts as an intermediary between a client's request for
a resource and the server providing that resource.
Purpose: Enhances security, improves performance, and controls access to resources by
managing requests on behalf of clients.
 System Logging Protocol (Syslog): standardized message communication among network
devices
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Function: It's a protocol that allows network devices to communicate with a logging
server using a standardized message format.
Usage: Facilitates easy monitoring of network devices by sending notification messages
under specific conditions.
Port: Typically uses port 514 for communication.
 LDAP (Lightweight Directory Access Protocol):
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Function: Used to access and update information in a network resource directory, often
for user authentication and directory services.
Port: Typically operates over port 389.
 SLP (Service Location Protocol):
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Function: Organizes and locates network resources like printers, disk drives, and
databases.
Port: Uses port 427 and is an alternative to LDAP in newer networks for resource
discovery.
 RDP (Remote Desktop Protocol):
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Function: Facilitates remote administration of a host using a graphical user interface
(GUI), allowing remote control of desktops or servers.
Port: Operates over TCP port 3389.
 DNS (Domain Name System) Protocol:
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Function: Used to translate human-readable domain names (e.g., www.example.com)
into IP addresses (e.g., 192.168.1.1) and vice versa.
Ports: DNS uses both TCP and UDP, typically over port 53, for name resolution
Transmission Control Protocol (TCP):
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Function: Provides connection-oriented, reliable data transmission in the TCP/IP
suite.
o Characteristics: Requires session establishment and acknowledgment for packet
delivery.
o Comparative Speed: Slower than UDP due to connection setup and
acknowledgments.
Hypertext Transfer Protocol Secure (HTTPS):
o Function: Ensures secure web content delivery using SSL/TLS encryption.
o Port: Typically operates over TCP port 443 to provide secure communication for
websites.
Simple Network Management Protocol (SNMP):
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Function: Used for monitoring and managing network devices.
Ports: SNMP uses UDP ports 161 and 162. Devices send data to a management
system, and agents maintain configuration and usage data.
Trivial File Transfer Protocol (TFTP):
o Function: Used to transfer files to/from remote hosts, often for firmware updates
or boot processes.
o Port: Operates over UDP port 69 and is commonly used with embedded devices
and system boot procedures.
Dynamic Host Control Protocol (DHCP):
o Function: Allocates IP addresses to hosts joining a network, simplifying network
configuration.
o Ports: DHCP utilizes UDP ports 67 and 68 for communication between clients
and servers.
TCP ensures reliable data transmission,
HTTPS secures web communication,
SNMP manages network devices,
TFTP facilitates file transfers,
DHCP automates IP address allocation in networks.
1. RJ-45 Connector:
o Function: Used for network and VoIP telephone cables.
o Type: 8-pin/8-position plug or jack.
o Usage: Connects computers to Ethernet-based local area networks (LAN).
o Wiring Schemes: Two common wiring schemes - T568A and T568B.
2. RJ-11 Connector:
o Function: Terminates cables for phone lines.
o Type: Smaller than RJ-45 and typically used for telephone connections.
3. Molex Connector:
o Function: Provides power from a computer's power supply to internal
components.
o Usage: Commonly used for connecting hard drives, optical drives, and other
internal devices.
1. Zigbee:
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Purpose: Used for home automation and IoT (Internet of Things) applications.
Open-Source: Zigbee is an open-source protocol, unlike the proprietary Z-Wave.
Frequency: Operates in the 2.4 GHz frequency band, providing higher data
bandwidth but potentially more interference.
o Device Support: Supports up to 65,000 devices in a single network with no hop
limit.
2. Z-Wave:
o Purpose: Primarily used for low-power home automation.
o Frequency: Utilizes radio frequencies in the 800 MHz and 900 MHz ranges.
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Device Support: Supports up to 232 devices in a network.
Proprietary: Z-Wave is a proprietary protocol.
3. Bluetooth:
o Purpose: Used for short-distance data exchange between devices like mice,
headphones, and smartphones.
o Frequency: Operates in the 2.402 GHz to 2.480 GHz industrial, scientific, and
medical radio bands.
o Personal Area Network (PAN): Used to build personal area networks for
connecting devices.
4. Near-Field Communication (NFC):
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Purpose: Enables close-range communication (within 4 cm) between electronic
devices, often used for contactless payments, file transfers, and contact sharing.
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Zigbee is open-source and operates at 2.4 GHz with support for many devices
Z-Wave is proprietary and operates at lower frequencies
Bluetooth is for short-distance device connections,
NFC facilitates close-range communication for various purposes.
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Color Depth: Refers to the number of bits used to represent the color of a single pixel in
an image or video.
Windows 10: Supports up to 32-bits of color depth if the monitor is compatible.
Color Range: A larger color depth allows for a wider range of unique colors to be
displayed.
Examples:
o 4-bit color depth offers 16 colors.
o 8-bit color depth provides 256 colors.
o Common settings include 16-bit (65,536 colors), 24-bit (16.7 million colors), or
32-bit (4.2 billion colors) on most Windows systems.
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Rapid Elasticity and Data Remanence:
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Rapid Elasticity: Refers to the ability to scale cloud resources up or down as
needed quickly.
o Data Remanence: The residual data that remains even after deletion.
o Security Concern: When cloud resources are deprovisioned, the data may not be
completely erased, potentially exposing it to the next user.
o Solution: Encrypting cloud-based storage drives by default can prevent data
remanence from being accessible to others.
2. Metered Services:
o Definition: These services charge users based on actual usage, often on an hourly
or monthly basis.
o Example: AWS Lambda charges based on the number of requests processed.
o Payment Model: Users pay for the resources they consume, making it costeffective and flexible.
3. Resource Pooling:
o Concept: It allows virtual environments to allocate memory and processing
capacity as needed for virtual machines (VMs).
o Efficiency: Resources are shared among multiple VMs, maximizing utilization
and efficiency.
4. On-Demand Services:
o Definition: Users can provision computing resources automatically without
requiring human interaction with service providers.
o Flexibility: Provides agility by allowing users to access resources as needed,
without the need for manual intervention.
1. Rapid elasticity enables flexible resource scaling but can pose security risks if data isn't
properly erased.
2. Metered services charge based on actual usage,
3. resource pooling maximizes efficiency,
4. on-demand services offer flexibility and automation in resource provisioning.
 Simple Network Management Protocol (SNMP):
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Function: Used for monitoring and managing network devices.
Ports: SNMP typically operates over UDP ports 161 and 162.
Components: Involves a management system collecting data from agents on devices,
with agents maintaining a Management Information Base (MIB) and the ability to
generate traps for notable events.
 Simple Mail Transfer Protocol (SMTP):
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Function: Enables the sending of emails between hosts on the Internet.
Port: Uses TCP port 25 for email transmission.
 Domain Name System (DNS) Protocol:
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Function: Provides name-to-IP address mapping on the Internet.
Ports: DNS operates over both TCP and UDP, commonly using port 53.
 Network Basic Input/Output System (NetBIOS)/NetBIOS over TCP/IP (NetBT):
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Function: Provides name registration and resolution services, particularly on legacy
Microsoft networks and those using WINS (Windows Internet Naming Service).
Ports: Operates on TCP/UDP ports 137 and 139.
NMP is used for network device management
SMTP for email transmission
DNS for name resolution,
NetBIOS/NetBT for name services on legacy Microsoft networks.
1. STP (Shielded Twisted Pair):
o Purpose: Used to prevent electrical interference and cross-talk in data
transmission.
o Cross-Talk: Occurs when electrical interference disrupts data signals, potentially
causing CRC errors (Cyclic Redundancy Check errors).
o CRC: A checksum calculation used to verify data integrity during transmission.
o STP Benefit: STP helps prevent interference from sources like fluorescent lights,
reducing the likelihood of data corruption.
2. UTP (Unshielded Twisted Pair):
o Characteristics: Cheaper and easier to work with compared to STP.
o Drawback: More susceptible to interference, making it less ideal in environments
with potential sources of electrical interference.
3. Coaxial and Fiber Cabling:
o Note: These are not types of CAT 5e cabling.
o Coaxial Cable: Often used for cable television (e.g., RG-6) and broadband
connections.
o Fiber Optic Cable: Utilized for high-speed data transmission over long distances
using light signals.
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STP cabling helps prevent interference and cross-talk in data transmission, reducing
the risk of data corruption
UTP is more cost-effective but less resistant to interference.
Coaxial and fiber cables are distinct from CAT 5e cabling and serve different
purposes in networking.
IDE (Integrated Drive Electronics) Cable:
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Purpose: Used for data transmission between the motherboard and internal devices like
hard drives and CD-ROM drives.
Description: IDE cables are 40-pin ribbon cables.
Speed: Operated at relatively slow speeds, typically less than 50 Mbps.
Terminology: IDE cables are also known as PATA (Parallel ATA) cables, in contrast to
SATA (Serial ATA) cables.
Current Usage: IDE cables are rarely used in modern computers but may be found in
legacy or very old machin
1. Measured Service:
o Definition: In cloud computing, it refers to services where the provider measures
and monitors service provision for purposes such as billing, resource
optimization, and predictive planning.
o Usage: Helps cloud providers manage and optimize resource allocation, ensuring
efficient use of resources.
2. Rapid Elasticity:
o Definition: Describes the ability of cloud services to quickly and easily scale
resources up or down in response to fluctuating user demands.
o Importance: Crucial for meeting changing workload requirements efficiently, but
can lead to system loading due to frequent resource allocation/deallocation.
3. On-Demand:
o Definition: Allows cloud consumers to autonomously provision computing
resources like server time and network storage as needed, without requiring
manual intervention from service providers.
o Benefit: Provides flexibility and agility in resource provisioning and
management.
4. Resource Pooling:
o Concept: Refers to the ability of virtualized environments to efficiently allocate
memory and processing capacity for the use of virtual machines (VMs).
o Efficiency: Maximizes resource utilization by sharing and allocating resources
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Measured service involves monitoring cloud services for various purposes
. rapid elasticity enables quick resource scaling
on-demand provisioning offers user autonomy
; resource pooling optimizes resource allocation in virtual environments. Dynamically
among VMs.
Molex Connector:
o Purpose: Provides DC power to drives inside a computer case.
o Types: Molex and Mini-Molex (4-pin connectors).
o Usage: Mini-Molex is for floppy disk drives, while the larger Molex is for hard
disk drives, CD-ROM drives, and DVD drives.
SATA Connector:
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Varieties: Comes in 15-pin and 7-pin versions.
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Usage: Commonly used to connect storage devices like hard drives and SSDs to
the motherboard.
Thunderbolt Connector:
o Varieties: Available in 20-pin and 24-pin versions.
o Usage: Used for high-speed data transfer and connecting peripherals like external
drives and monitors.
SCSI Connector:
o Varieties: Comes in 50-pin and 36-pin versions.
o Usage: Historically used for connecting various peripherals like scanners,
printers, and hard drives, particularly in older system
 Metropolitan Area Network (MAN):
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Scope: Connects users and resources within a city or metropolitan area.
Technology: Often uses municipal broadband and Wi-Fi to cover large parts of the city
through a wireless mesh network.
Deployment: Involves deploying numerous wireless access points, usually outdoors on
poles.
 Wireless Mesh Network (WMN):
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Topology: All nodes, including client devices, can forward data and discover paths,
enhancing coverage and throughput.
Usage: Commonly used in MANs to improve wireless connectivity, especially in outdoor
environments.
 Local Area Network (LAN):
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Scope: Connects devices within a limited area, like a single building or campus.
Connectivity: Nodes in a LAN are directly connected through cables or short-range
wireless technology.
 Personal Area Network (PAN):
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Scope: A close-range network for communication between personal devices like
smartphones, laptops, and peripherals.
Technologies: Typically based on Bluetooth or NFC for short-distance connections.
 Wide Area Network (WAN):
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Scope: Spans multiple geographic locations, often covering large areas like the Internet.
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Establishment: WANs are created using leased telecommunication circuits to connect
distant locations
Refresh Rate:
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Definition: The number of times an image is redrawn on a monitor per second,
measured in Hertz (Hz).
o Common Values: Monitors are typically rated at 60 Hz, 72 Hz, or 120 Hz, with
higher rates providing smoother visuals, which is especially valuable for gaming.
Aspect Ratio:
o Definition: The ratio of a display's width to its height.
o Example: A common aspect ratio is 16:9, indicating 16 units of width for every 9
units of height.
Frame Rate:
o Definition: The speed at which individual frames in a video stream change per
second, measured in Hertz (Hz) or Frames per Second (fps).
o Usage: Higher frame rates result in smoother and more fluid video playback.
Resolution:
o Definition: The measure of the number of pixels an imaging device can use to
display an image, often expressed as pixels per inch (PPI).
o Impact: Higher resolutions result in sharper and more detailed images.
Yaw Rate: is used as a distractor.
 Coaxial Cable:
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Usage: Commonly used for transmitting video, communications, and audio.
Structure: Contains a copper core for signal transmission, surrounded by plastic
insulation and shielding to protect against electromagnetic interference (EMI).
Application: Often used to connect TVs to cable TV services.
 Plenum-Rated Cable:
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Purpose: Equipped with special insulation with low smoke and low flame properties.
Requirement: Mandated for installation in air handling spaces for safety.
 Shielded Cable:
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Structure: Includes a braided foil shield around the inner cabling.
Function: Provides protection against electromagnetic interference (EMI).
 Optical Fiber Cable:
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Components: Consists of an ultra-fine glass core for carrying light signals, surrounded
by glass or plastic cladding for guidance, and a protective coating.
Characteristic: Uses light signals to transmit data at extremely high bandwidths.
Termination: Terminated by connectors and contained within a protective jacket
 SMTP (Simple Mail Transfer Protocol):
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Function: Used to send emails between hosts on the Internet.
Port: Typically operates over TCP port 25.
Role: Responsible for sending outgoing emails.
 POP3 (Post Office Protocol 3):
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Function: Allows a client to retrieve email messages from a remote server.
Port: Typically uses TCP port 110.
Behavior: Messages are usually deleted from the server after being downloaded by the
client.
 IMAP (Internet Message Access Protocol):
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Function: Provides a means for clients to access email messages stored on a remote
server.
Port: Typically operates on TCP port 143.
Behavior: Messages persist on the server even after being downloaded by the client.
Supports mailbox management and concurrent access.
 HTTPS (Hypertext Transfer Protocol Secure):
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Function: Ensures secure communication between web browsers and servers by using
SSL/TLS encryption.
Port: Typically uses TCP port 443.
Usage: Primarily employed for secure web browsing, not for email
MTP is used for sending emails, POP3 and IMAP are used for receiving emails, and HTTPS is
for secure web browsing.
Antenna Wires in Laptops and Mobile Devices:
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Routing: Antenna wires for wireless cards and cellular radios are typically routed around
the screen within the device's casing.
Delicacy: These antenna connections are delicate and can be challenging to install or
remove.
Maintenance: When updating or replacing a wireless or cellular card, technicians must:
o Carefully reconnect the antenna wires.
o Ensure the wires are reinstalled in the correct location.
External Antennas: External antennas are an option, but they are only available when
connected to an external wireless card.
Virtual Machines vs. Physical Servers:
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Restoration Speed:
o Virtual Machine: Can be restored quickly using an instance, clone, or backup
restoration.
o Physical Server: Requires modifications for drivers and, in some cases, a new
server, leading to longer restoration times.
Driver Compatibility:
o Virtual Machine: Typically doesn't face driver compatibility issues when
restored.
o Physical Server: May require the right drivers for disk drives, NIC, and other
components during the rebuilding process.
Downtime:
o Virtual Machine: Experiences lower downtime during restoration.
o Physical Server: May involve extended downtime due to driver configuration
and replacement.
In summary, virtual machines are often faster and more efficient to restore compared to physical
servers, resulting in reduced downtime and quicker recovery.
Key Concepts in Cloud Computing:
1. Resource Pooling: Refers to the allocation of memory and processing capacity within a
virtual environment for the use of virtual machines (VMs).
2. Measured Service: An aspect of cloud computing where the cloud provider monitors
and measures services for purposes such as billing, resource optimization, and predictive
planning.
3. Synchronization App: Enables the storage and synchronization of files between a local
device (e.g., laptop) and a cloud service, ensuring the latest versions are maintained in
both locations. It supports collaboration among multiple users.
4. Virtual Application Streaming: A method to deliver applications to a user's workstation
directly from the cloud, allowing for efficient access to applications without the need for
local installation.
In summary, these concepts are fundamental to understanding cloud computing, resource
management, data synchronization, and application delivery from the cloud.
Email Protocols: Choosing IMAP vs. POP3:
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IMAP (Internet Message Access Protocol):
o Leaves emails on the server.
o Synchronizes emails across all devices, including read states.
o Supports mailbox management and multiple client access.
o Uses TCP port 143.
POP3 (Post Office Protocol 3):
o Downloads emails to the device and removes them from the server.
o May not synchronize read states across devices.
o Uses TCP port 110.
SMTP (Simple Mail Transfer Protocol):
o Used for sending emails.
o Operates on TCP port 25.
HTTPS (Hypertext Transfer Protocol Secure):
o Ensures secure web content delivery via SSL/TLS encryption.
o Utilizes TCP port 443 for secure web browsing.
In summary, choose IMAP for email setup if you want emails to stay on the server, synchronize
across devices, and manage mailboxes effectively. POP3 downloads emails to the device and
removes them from the server. SMTP is for sending emails, and HTTPS provides secure web
content delivery.