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Hardware and Networking Components: A Comprehensive Overview, Study notes of Computer science

Computer science

This document offers a detailed explanation of various hardware and networking components, including lcd technologies, mobile configurations, network ports and protocols, and troubleshooting techniques for printers and mobile devices. it's a valuable resource for understanding the fundamentals of computer hardware and networking, covering topics such as lcd types, usb and nfc communication, network protocols (tcp/udp, ipv4), and troubleshooting common issues in various devices. The document also delves into networking components like switches, routers, and firewalls, providing insights into their functionalities and configurations.

Typology: Study notes

2024/2025

Uploaded on 04/30/2025

thao-linh-nguyen-7 🇦🇺

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Section 1: Mobile Devices

1.1 - Laptop hardware

1.2 - Laptop displays

● Portable LCD

- Liquid crystal display

- Light sources shine through layers of liquid crystals

● Advantages

- Lightweight

- Low power

- Cheap

● Disadvantages

- Requires a separate backlight: fluorescent, LED -> Difficult to replace if backlight is

broken

- Difficulties displaying true black

● LCD technologies:

- TN (twisted nematic) LCD

+ OG LCD tech

+ Fast response time -> good for gaming

+ Bad viewing angles

- IPS (In-Plane Switching) LCD

+ Excellent colour representation -> Good for design, publishing

+ Expensive

- VA (Vertical Alignment) LCD

+ In between TN and IPS

+ Decent colour representation

+ Slower response time than TN

● OLED (Organic Light Emititng Diode)

- Organic compound emits light when receiving an electric current

- No backlight (organic compound provides light), no liquid crystals -> Thinner and

lighter

- Flexible, no glass needed

- Used on phone, tablet, smartwatch

- More expensive than LCD

● Wifi antenna

- Wifi and bluetooth wires run around the display

- When replacing the display, have to rewire these cables

● Fluorescent vs LED backlighting

- CCFL - Cold Cathode Flourescent Lamp

- Needs more voltage and power than LED

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Download Hardware and Networking Components: A Comprehensive Overview and more Study notes Computer science in PDF only on Docsity!

Section 1: Mobile Devices

1.1 - Laptop hardware

1.2 - Laptop displays

● Portable LCD

Liquid crystal display
Light sources shine through layers of liquid crystals ● Advantages
Lightweight
Low power
Cheap ● Disadvantages
Requires a separate backlight: fluorescent, LED -> Difficult to replace if backlight is broken
Difficulties displaying true black ● LCD technologies:
TN (twisted nematic) LCD
- OG LCD tech
- Fast response time -> good for gaming
- Bad viewing angles
IPS (In-Plane Switching) LCD
- Excellent colour representation -> Good for design, publishing
- Expensive
VA (Vertical Alignment) LCD
- In between TN and IPS
- Decent colour representation
- Slower response time than TN

● OLED (Organic Light Emititng Diode)

Organic compound emits light when receiving an electric current
No backlight (organic compound provides light), no liquid crystals -> Thinner and lighter
Flexible, no glass needed
Used on phone, tablet, smartwatch
More expensive than LCD

● Wifi antenna

Wifi and bluetooth wires run around the display
When replacing the display, have to rewire these cables

● Fluorescent vs LED backlighting

CCFL - Cold Cathode Flourescent Lamp
Needs more voltage and power than LED

Add thickness to the display
Only on older laptops
LEDs and be around the edge of the screen or and array behind the screen

● Backlight and inverter

LCD displays need a backlight
Inverter can be found on CCFL displays: convert DC to AC

● Digitiser

Use pen-like device as input
Digitiser + finger input = touchscreen

1.3 - Mobile configuration

● USB (Universal Serial Bus)

High-speed wired communication
Charging, data transfer ● DB-
Also called DE-
Commonly used for RS-232 signals
Traditionally used for modem connection
Now used as a configuration port
- Switch, router, firewall, etc
- Use a USB to DB-9 converter cable ● NFC (Near field communication)
Send small amounts of data wirelessly over a small distance
Short range with encryption support ● Bluetooth
High-speed communication over short distance
PAN (personal area network) ● Docking station
Proprietary connection (unique to each brand)

1.4 - Cellular Standards

● Cellular network

land is separated into cells
Antennas cover a cell with certain frequencies ● 2G network
GSM - Global System for Mobile communication
- Multiplexing: many people can communicate at the same time using the same frequency
CDMA - Code Division Multiple Access
- Same as GSM: everyone can communicate at the same time
- Each call uses a different code
- The codes are used to filter each call on the receiving side

1.5 - Mobile Device Configurations

Section 2: Networking

2.1 - Ports and Protocols

● TCP and UDP

Transported inside of IP packet
Encapsulated by the IP protocol
They’re 2 ways to move data from place to place
OSI layer 4 (transport layer)

Multiplexing ● TCP (transmission control protocol)
Connection-oriented
- A formal connection setup and close (3 way handshake)
Reliable delivery
- Error recovery
- Reorder messages
- Retransmission: data can be resent from source if not received
Flow control:
- If a device feels that it’s receiving information too quickly, it can tell the other side to slow down the process so that information can be received at a more reasonable rate ● Communication using TCP:
- HTTPS: send information in our web browsers
- SSH: provide an encrypted form of terminal communication between systems
- If our HTTPS data between a web server and a client somehow loses a packet between point A and point B -> TCP will recognise that packet was missing -> TCP asks to retransmit that information -> the transmitted data is sent over the network. All of this happens automatically with TCP and HTTPS and SSH don’t have to worry about managing the process of getting data from one side to the other. ● UDP (User Datagram Protocol)
Connectionless: No formal open or close to the connection
Unreliable:
- No error recovery
- No message reorder
- No retransmission: Sender determines the amount of data sent
When to use UDP
- Real-time communication (facetime, phone call, etc): when can’t stop to resend data - Other connectionless protocols:
- DHCP: used to automatically assign IP to device
- TFTP: simple, lightweight file transfer protocol that uses UDP. Information is simply sent across the network with no type of acknowledgment that the data was received on the other side. ● IPv4 sockets
Server IP address, protocol, application port number
Client IP address, protocol, client port number ● Non-ephemeral ports: permanent port numbers
Port 0 -
Usually on a server or service ● Ephemeral ports: temporary port numbers
Port 1024 - 65535
Determined in real time by client ● Port numbers:
TCP and UDP ports can be any number between 0 and 65535
Most servers use non-ephemeral port numbers
Port numbers are for communication, not security
Service port number needs to be well-known
TCP and UDP port numbers are different

POP3 - Post Office Protocol v
- tcp/
- Basic mail transfer functionality
IMAP4 - Internet Message Access Protocol 4
- tcp/
- Includes management of email inbox from multiple clients ● SMB - Server Message Block
Protocol used by MS
File sharing, printer sharing
Also called CIFS (Common Internet File System)
Using NetBIOS over TCP/IP on older machines
- udp/137 - netBIOS name services (nbname): used to find devices on the network by name
- tcp/139 - netBIOS session service (nbsession): set up session and transfer data
On modern devices: Direct SMB using tcp/ ● SNMP - Simple Network Management Protocol
Gather statistics from network devices
- queries: udp/
- traps: udp/
- v1: original, structured table, in-the-clear data +v2: data type enhancements, bulk transfer, still in-the-clear
- v3: Secure standard, message integrity, authentication. encryption ● LDAP - Lightweight directory access protocol)
tcp/
Store and retrieve information in a network directory
Commonly used in MS Active Directory ● RDP
Share a desktop from a remote location
tcp/
Built in to Windows
Can connect to an entire desktop or just an app
Clietns for Mac, Linux, Android, etc

Network Devices

● Routers (layer 3)

Route traffic between IP subnets
Make forwarding decisions based on IP address
Router inside a switch sometimes called “layer 3 switches”
Connects diverse network types: LAN, WAN, copper, fiber ● Switches (layer 2 - data link)
Used to connect devices within a local network (LAN)
Forward traffic based on data link address (MAC)
Has many ports
May provide power over ethernet ● Unmanaged switch
Very few configuration options

No VLAN
No management protocols -> little integration to other devices
Low price point ● Managed switch
VLAN support
Traffic priotisation - voice traffic gets higher priority
Redundancy support - Spanning Tree Protocol
Port mirroring ● Access point
Bridge the wired network onto wireless
Make forwarding decisions based on MAC address ● Patch Panels
Combination of punch-down blocks and RJ-45 connectors
Connections from desks are made once
Patch panel to switch can be easily changed ● Firewall
Filter traffic by port numbers (Layer 4)
Firewalls that can filter based on application is Layer 7
Can encrypt traffic in/out of the network
Can proxy traffic
Most firewall can act as a router ● PoE
Power is provided on an ethernet cable: 1 wire for internet + power
Endspan: A PoE-enabled switch that provides both data and power directly over the Ethernet cable.
Midspan: A separate PoE injector or PoE hub that adds power to an Ethernet cable between a non-PoE switch and a PoE device. ● PoE Standards:
PoE: IEEE 802.3af-
- The OG PoE specification
- now part of the 802.3 standard
- 15.4W DC power, 350mA max current
POE+: IEEE 802.3at-
- now part of the 802.3 standard
- 25.5W DC power, 600mA max current
POE++: IEEE 802.3bt-
- 51W DC power, 600mA max current (type 3)
- 71.3W DC power, 960mA max current (type 4)
- PoE with 10GBASE-T ● Hub
Multi-port repeater
Traffic going in one port is repeated to every other port
Everything is half duplex (can only send or receive data at a time, not simultaneously)
Become less efficient as network traffic increases ● Cable modem

More frequency conflicts: phone, microwave, bluetooth
Max speed: 11Mb/s ● 802.11g - 802.11b upgrade
2.4GHz range
Max speed 54Mb/s
Backwards compatible with 802.11a
Same frequency conflict problem ● 802.11n (Wifi 4)
2.4 and/or 5GHz (if access point support)
40MHz channel width -> more data transfer at the same time
Max speed: 600Mb/s
MIMO: multiple transmit and receive antennas ● 802.11ac (Wifi 5)
Operates exclusively on 5GHz range
Increased channel bonding -> larger bandwidth usage
Denser signalling modulation -> faster data transfer
8 MU-MIMO downlink steam ● 802.11ax (Wifi 6)
2.4 and/or 5GHz
20, 40, 80, 160 MHZ channel width
1202MB/s
Improve high density installation

● Long-range fixed wireless

Used to connect 2 buildings far awat:
- Fixed directional antenna: focused, point 2 point connection
- Increased signal strength: minimal signal absorption or bounce ● RFID
Radio energy transmitted to the tag
RF powers the tag, ID is transmitted back
Bidirectional communication

Wireless Network Technologies

● 802.11 technology

Frequency: 2.4 or 5GHZ or both
Channels:
- Groups of frequencies, numbered by IEEE
- Channel should be non-overlapping
Most gov have regulations to manage frequency, power, spectrum, etc

Network Services

● DHCP server: automatic IP address configuration

Very common service
Enterprise DHCP will be redundant ● File server
Centralised storage of files
Standard system of file management: SMB, AFP, etc
Front-end hides the protocol ● Print server
Connect a printer to the network
Maybe a software in a computer or built in to the printer
Uses standard printing protocol (SMB, IPP, LDP) ● Mail server
Store incoming and send outgoing mails
Usually managed by the ISP or enterprise IT department
Important, 24x7 support ● Syslog

IPv4 and IPv

● Addressing with IPv

Every device must have unique IP address
Subnet mask is used by local device to determine which subnet it’s on
Default gateway: used to communicate outside of local subnet
Default gateway must be an IP on the local subnet

Assigning IP Addresses

● DHCP process: DORA

Discover a DHCP server
Offer: get an offer
Request: lock in the offer
Acknowdge: DHCP confirmation ● Dynamic and static IP
DHCP assigns an IP address from a large pool of addresses => IP address might change
Sometimes IP address should not be changed: server, printer, personal preference
Disable DHCP, manual IP assignment => require additional admin
Better: configure an IP address reservation on the DHCP server
- Associate a specific MAC address with an IP address

DHCP server keeps a list of past assignments and give the same address if available

Address reservation
- Administratively configured
- Each MAC address has a matching IP address
- Also called static DHCP, IP reservation
DHCP lease
- The duration the device can use the assigned IP (time controlled by admin)
- Reallocation: if computer restarts, it has to renew the lease
- Workstation can also manually release the IP address, i.e to move to another subnet ● DHCP renewal
T1 timer
- Check in with the lending DHCP server to renew the IP address
- At 50% of the lease time
T2 timer
- If the original DHCP server is down, try rebinding with any DHCP server
- At 87.5% of the lease time (7/8th)

VLANs and VPNs

● VPN

Encrypted data traversing a public network
Concentrator:
- Encryption/decryption access device
- Often integrated into a firewall
Diffrenet deployment options:
- Specialised cryptopgraphic hardware
- VPN software

Internet Connection Types

● Satellite networking

Communication to a satellite (non-terrestrial communicatio0n)
Hight cost

Used for remote sites, difficult to reach sites
Relatively low speed (50Mb/s down, 3Mb/s up)
High latency (250ms up down)
High frequency (2GHz)
Can be affected by weather: rain ● Fiber
High speed
High installation cost and repair cost
Communicate over long distance
Largely used in WAN core: support very high data rate ● Cable broadband
Broadband:
- Transmission across multiple frequencies
- Different traffic types
DOCSIS: Data on the cable network
- High speed: 50-1000Mb/s
- Support multiple services: data, voice, video ● DSL
ADSL: uses telephone line
Download speed > upload speed
- 200mb/s down - 20mb/s up
- 10000ft limit from central office
- Faster speed near central office ● Cellular network
Mobile device
Seperate land into “cell”
Tethering: turning phone into a wireless router
Mobile hotspot ● WISP (wireless internet service provider)
Terrestrial internet access using wireless
Connect rural areas
Different deployment technologies: meshed 802.11, 5G home internet, proprietary wireless
Need an outdoor antenna: 10-1000mb/s

Network Cables

● Twisted pair copper cabling

Balanced pair operation
- 2 wires with equal and opposite signals
- Transmit+/Transmit-, Receive+/Receive-
Twisting:
- Keeps a single wire constantly moving
- The opposite signals are compared on the other end
Pairs in the same cable have different twist rate

Additional shielding protects against interference
Requires cable to be grounded

● Direct burial STP

Provides protection from the elements:
- Waterproof
- Filled with gel to repel water
- Conduit may not be needed
STP:
- Provides grounding
- Add strength
- Protects against signal interference

Optical Fiber

Transmisison by light
No radio frequency (RF)
- very hard to monitor or tap -> more secure
- Immune to radio interference
Tranmission over long distance ● Multimode fiber
Short-range communication: up to 2km
Use inexpensive light source (LED) ● Single-mode fiber
Long-reange communication: Up to 100km without processing
Use expensive light source: laser

568A and 568B Colors

● Pin assignments from T568-B standard

8 conductor 100-ohm balanced twisted-pair cabling ● T568A and T568B are different pin assignments for 8P8C connectors
Assign the T568A pin-out to horizontal cabling ● Many org traditionally use 568B

Difficult to change mid-stream

Peripheral Cables

AHCI vs NVMe

M.2 interface
- Doenst guarantee NVMe: your M.2 interface maybe using AHCI
- motherboard might only support 1 type of m.

Data can be rebuilt using parity is corrupted

The speed of striping but
The redundancy of mirroring
Need at least 4 drives

The BIOS

Basic Input/Output system
The software used to start your computer
When you power on your system, it initializes the memory and the CPU, and it begins executing the code of the BIOS.
Once BIOS is booted, it will start the POST (power-on self test) and look for a boot loader (operating system)

Hardware and Networking Components: A Comprehensive Overview, Study notes of Computer science

Related documents

Partial preview of the text

Download Hardware and Networking Components: A Comprehensive Overview and more Study notes Computer science in PDF only on Docsity!

Section 1: Mobile Devices

1.1 - Laptop hardware

1.2 - Laptop displays

1.3 - Mobile configuration

1.4 - Cellular Standards

1.5 - Mobile Device Configurations

Section 2: Networking

2.1 - Ports and Protocols

Network Devices

Wireless Network Technologies

Network Services

IPv4 and IPv

Assigning IP Addresses

VLANs and VPNs

● VPN

Internet Connection Types

Network Cables

Optical Fiber

568A and 568B Colors

Peripheral Cables

AHCI vs NVMe

The BIOS