Core 1 (220-1101)

Laptop hardware

• Engineered to precise specifications

- A challenging repair

• Some laptops are easier to fix than others

- An ongoing learning process

• Understand the process

- The details will vary between laptop manufacturers

Laptop batteries

• The power source when unplugged

- May be easily replaced or require a tear down

- Five minutes vs. one hour

• Lithium-Ion (Li-ion) and

- Lithium-Ion polymer (LiPo) are common

- No "memory effect"

- Charging the battery diminishes capacity

• Different form factor for each laptop

- Battery types and styles can vary

- Battery technology is changing constantly

Laptop keyboard

• The most-used component of the laptop

- Can be easy to replace

- A few screws and a single ribbon cable

- May not always be this simple

• Or connect an external USB keyboard

Not very portable, but works in a pinch

Laptop keys

• Some repairs might require the removal or replacement of a key cap

- This can be a delicate procedure

• Check with the manufacturer's instructions

- It's very easy to accidentally break the key cap or the components underneath

Laptop memory

• Small Outline Dual In-line Memory Module (SO-DIMM)

• Memory used in laptops and mobile devices

- Often easy to install and replace

• Some laptop memory is soldered to the system board

- No upgrade available

- Requires a full system board replacement

Laptop storage

• Magnetic disk

- Traditional spinning drive platters

- 2.5 form factors (3.5 inch for desktops)

• SSD (Solid-state drive)

- All memory, no moving parts

- Silent, fast access time, less latency

- 2.5 inch form factors

• M.2

- Smaller form factor

- No SATA data or power cables

- Easy to install and replace

Replacing laptop storage

• All internal

- Open a cover on the back

- Open the entire laptop

• Can be very modular

- Two screws and the drive slides out

• M.2 drives are even easier

- One screw - similar to RAM installation

Migrating from HDD to SSD

• An impressive upgrade

- Move from spinning mechanical drive to solid state memory

- It's almost like getting a new laptop

• Install an OS on the SSD

- Move user documents between drives

- Install any required applications

- Can be time consuming

• Image/clone the HDD

- No OS installation required

- Move everything from one to the other

• Imaging software needed

- Sometimes included with the SSD

- Many commercial and open source options

• Create an image file - One drive at a time

• Drive-to-drive image

- Image directly from one drive to the other

802.11 wireless

• Wireless network connectivity

- Connect without wires

• 802.11

- Local area network (LAN)

- High speed, Internet access

Biometrics

• Sign in or unlock your laptop with a fingerprint reader or face recognition

- Something you are

• Requires additional configuration in the OS

- Hardware required for most options

• Relatively secure

- Faces and fingerprints are quite unique

Near-field communication (NFC)

- 4 centimeters or less

- Data transfers or authentication

• Common on mobile phones and smart watches

- Payment method on your wrist

• Use it for authentication without typing a password

- Hospital workstations, warehouses, manufacturing

• Near Field Communication

- Send small amounts of data wirelessly over a limited area

• Built into your phone

- Payment systems, transportation,in-person information exchange

• Access token, identity "card"

- Short range with encryption support

• Two-way wireless communication

- Builds on RFID, which is mostly one-way

• Payment systems

- Major credit cards, online wallets

• Bootstrap for other wireless

- NFC helps with Bluetooth pairing

• Access token, identity "card"

- Short range with encryption support

Portable LCD

• Liquid crystal display

- Light shines through liquid crystals

• Advantages

- Lightweight

- Relatively low power

- Relatively inexpensive

• Disadvantages

- Black levels are a challenge

- Requires separate backlight

- Florescent, LED, etc.

- Lights are difficult to replace

LCD technologies

• TN (Twisted Nematic)

- Fast response times (gaming!)

- Poor viewing angles - color shifts

• IPS (In Plane Switching)

- Excellent color representation

- More expensive to produce than TN

• VA (Vertical Alignment)

- A good compromise between TN and IPS

- Good color representation

- Slower response times than TN

Organic Light-Emitting Diode (OLED)

- Organic compound emits light when receiving an electric current

• Thinner and lighter

- Flexible and mobile - no glass needed

• No backlight

- The organic compound provides the light

• Laptops, phones, smart watches

- Very accurate color representation

- A bit higher cost than LCD

Wi-Fi antennas

• Multiple antennas

- WiFi main and aux / Bluetooth

• Antenna wires wrap around the laptop screen

- It's up high!

Camera / Webcam

• Usually includes both audio and video

- Specialized drivers and software

• Internal or external

- Commonly external on desktops, internal on laptops/tablets/phones

• Accessible from multimedia applications, photo utilities,and video conferencing

- Real-time video communication

Microphone

• Built-in to the laptop display

- Useful for video calls

• Not good for non-casual use

- Analog or USB microphones can help

Fluorescent

• LED-backlit LCD display

- Backlight is LEDs instead of florescent

- LEDs around the edge of the screen

- An array of LEDs behind the screen

- The latest laptops are LED-backlit

LED backlighting

• CCFL - Cold Cathode

- Fluorescent Lamp

- Higher voltage and power needed

- Added thickness to the display

- No longer a common backlight

- Older laptops will use these

Backlight and inverter

- Florescent lamp/LED to LCD display to your eyes

• Some laptops have inverters - Turn DC into AC

• Verify backlight

- Look closely and use a flashlight

• May need to replace the LCD inverter or display

- Choose carefully

Digitizer

- Stylus input - Useful for graphical input

• Used commonly on laptop / tablets

- Or hybrid devices

Touchscreen

• Merge laptop and tablet input

- Digitizer responds to touch - No keyboard required

• But often still available

- Many options for input - Use the best one for the job

Connecting mobile devices

• Phones and tablets

- Many different ways to connect

• Wired and wireless connectivity

- Standards and options change through the years

• Used for synchronization, connectivity, backup, and identification

- Sometimes simultaneously

Universal Serial Bus (USB)

- High-speed wired communication

- Used for charging and data transfers

• Micro-USB

- A smaller USB connection

- Common now worldwide

• Older devices may use Mini-USB

- Slightly larger

• Simplify connections - Printers, storage devices, keyboard, mouse

• USB 1.1

- Low speed: 1.5 megabits per second, 3 meters

- Full speed: 12 megabits per second, 5 meters

• USB 2.0 - 480 megabits per second, 5 meters

• USB 3.0 - SuperSpeed

- 5 gigabits per second, ~3 meters

- Standard does not specify a cable length

USB-C

• 24-pin double-sided USB connector

- Used for both hosts and devices

• Acts as a USB 2.0/3.0/3.1/4 connection

- Different signals can use the same connector

• Can transmit other signals

- DisplayPort, HDMI, Thunderbolt

• USB has a lot of different connectors

- And they have changed over time

• Can be annoying to connect USB-A

- Third time's the charm

• USB-C replaces all of these

- One connector to rule them all

• USB-C describes the physical connector

- It doesn't describe the signal

• Used for USB, Thunderbolt

- Interface is the same, signal can vary

Lighting

- 8-pin digital signals

• Some advantages over Micro-USB

- Higher power output for phones and tablets

- Can be inserted either way

- Simpler design

Serial interfaces

• DB-9 - also called DE-9

• Commonly used for RS-232 signals

- Recommended Standard 232

- An industry standard since 1969

• Serial communications standard

- Traditionally used for modem connections

• Now used as a configuration port

- Switches, routers, firewalls, etc

- Use a USB to DB-9 converter cable

Bluetooth

- Personal area network (PAN) - Short range

- Connect peripherals and other nearby devices

• High speed communication over short distances

- PAN (Personal Area Network)

• Connects our mobile devices

- Smartphones

- Tethering

- Headsets and headphones

- Health monitors

- Automobile and phone integration

- Smartwatches

- External speakers

• Remove the wires

- Headsets, speakers, keyboards / mice

• Uses the 2.4 GHz range

- Unlicensed ISM

(Industrial, Scientific and Medical) band

- Same as 802.11

• Short-range

- Most consumer devices operate to about 10 meters

- Industrial Bluetooth devices can communicate over 100 meters

Hotspot

- Extend the cellular data network to all of your devices

• Dependent on phone type and provider

- May require additional charges and data costs

Touch pens

- Activate the interface without actually touching it

• Handwriting

- Note taking, signatures

• Precise selection

- Easier to see the screen

• Useful in the winter

- Keep your gloves on

Active stylus

- A more advanced writing tool

• The stylus communicates directly to the device

- Pressure sensitivity, programmable buttons, etc.

• Must be compatible with the tablet

- e.g., Apple iPad uses an Apple Pencil

Drawing pad

• Use an active stylus with an external digitizer

- Very precise input

Trackpad (Touchpad)

- Useful in tight working areas

- Common on laptops

• External options

- Battery powered

- Bluetooth connected

• Drag and tap

- Or use multiple finger input for right-clicking, zooming, and window control

• Enable and disable

- Avoid inadvertent mouse clicks and movements

Headsets

• Wired

- USB connections are common on laptops

- Connects to 3.5 mm

TRRS (tip-ring-ring-sleeve) connector

- Analog audio jack

- iPhone can use Lightning port

• Wireless - Bluetooth headsets

Speakers

• Mobile audio - Battery powered

• Wireless connection - Bluetooth link

• Stereo sound - Small package

Docking station

- Use external keyboard and mouse

- Extend existing laptop interfaces

- Add additional functionality

- Desktop adapter cards

- Avoid cable issues

Port replicator

- Similar to a docking station

- Does not commonly have an expansion card option

- Usually connects using USB

Cellular networks

• Mobile devices

- "Cell" phones

• Separate land into "cells"

- Antenna coverages a cell with certain frequencies

• 2G networks

- GSM - Global System for Mobile Communications

- CDMA - Code Division Multiple Access

• Poor data support

- Originally used circuit-switching

- Minor upgrades for some packet-switching

• Tethering

- Turn your phone into a wireless router

• Mobile hotspot

- Standalone devices

- Use your phone for other things

Global System for Mobile Communications (GSM)

- Mobile networking standard

• 90% of the market

- Originally an EU standard

- Worldwide coverage

• Used by AT&T and T-Mobile in the United States

- Move your SIM card (Subscriber Identity Module) from phone to phone

• Original GSM standard used multiplexing

- Everyone gets a little slice of time

Code Division Multiple Access (CDMA)

- Everyone communicates at the same time

- Each call uses a different code

- The codes are used to filter each call on the receiving side

• Used by Verizon and Sprint

- Handsets are controlled by the network provider

Not much adoption elsewhere

3G technology

- Introduced in 1998

- Usually several megabits per second

• Bandwidth improvement allowed new functionality

- GPS

- Mobile television

- Video on demand

- Video conferencing

4G and LTE

- Converged standard (GSM and CDMA providers)

- Based on GSM and EDGE

(Enhanced Data Rates for GSM Evolution)

- Standard supports download rates of 150 Mbit/s

- Standard supports download rates of 300 Mbit/s

5G

- Launched worldwide in 2020

• Significant performance improvements

- At higher frequencies

- Eventually 10 gigabits per second

- Slower speeds from 100-900 Mbit/s

• Significant IoT impact

- Bandwidth becomes less of a constraint

- Larger data transfers

- Faster monitoring and notification

- Additional cloud processing

Updates

• PRL (Preferred Roaming List) updates

- CDMA networks (i.e., Verizon, Sprint)

• Allows your phone to connect to the right tower

- Can be updated over the air (OTA)

Bluetooth pairing

- Built-in security - Use or verify a PIN

- Future connections should be automatic

• Check with the manufacturer

- May prefer a specific sequence

- Discoverable mode isn't always obvious

Bluetooth pairing process

- Android and iOS: Settings / Bluetooth

- May require key sequence on Bluetooth device

- Many devices may appear!

• Enter or confirm PIN

- Should be the same on both devices

• Test connectivity

- Devices should now communicate

Global Positioning System (GPS)

• Created by the U.S. Department of Defense

- Over 30 satellites currently in orbit

• Precise navigation - Need to see at least 4 satellites

• Determines location based on timing differences

Longitude, latitude, altitude

• Mobile device location services and geotracking

- Maps, directions

- Determine physical location based on GPS, WiFi, and cellular towers

Mobile Device Management (MDM)

• Manage company-owned and user-owned mobile devices

- BYOD - Bring Your Own Device

• Centralized management of the mobile devices

- Specialized functionality

• Set policies on apps, data, camera, etc.

- Control the remote device

- The entire device or a "partition"

MDM configuration

• Corporate email configuration

- User does not need to configure anything

- The MDM makes the changes on the device

- Account details, server address, communication method

• Two-factor authentication

- Require specific authentication types

- Biometrics, pseudo-random authentication app

• Corporate applications

- Allow or restrict app installation

- Prevent unauthorized app usage

Configuring a mobile device

- Telephone / Text messaging

• Email

- Everyone handles email services differently

- Corporate email configurations can vary

• Data synchronization

- Based on data rates and speeds

- Important for backup and recovery

Microsoft 365

- Usually the same for Hotmail and Outlook.com

- Username, password

• Select the items to synchronize

• Same process for Google Workspace

- Formerly known as G Suite

iCloud

• Select synchronization options

- Extensive customization

- Use your desktop, laptop, or mobile device

Synchronizing data

- Mail

- Pictures, music, video

- Calendar

- Contacts

• Data caps and transfer costs

- Cellular vs 802.11

- Enable or disable network connections

- Control the use of cellular downloads

A series of moving vans

• Efficiently move large amounts of data

- Use a shipping truck

• The network topology is the road

- Ethernet, DSL, cable system

• The truck is the Internet Protocol (IP)

- We've designed the roads for this truck

• The boxes hold your data

- Boxes of TCP and UDP

• Inside the boxes are more things

- Application information

TCP and UDP

• Transported inside of IP

- Encapsulated by the IP protocol

• Two ways to move data from place to place

- Different features for different applications

• OSI Layer 4

- The transport layer

• Multiplexing

- Use many different applications at the same time

- TCP and UDP

TCP - Transmission Control Protocol Communication

TCP - Transmission Control Protocol

• Connection-oriented

- A formal connection setup and close

• "Reliable" delivery

- Recovery from errors

- Can manage out-of-order messages or retransmissions

• Flow control

- The receiver can manage how much data is sent

UDP - User Datagram Protocol

• Connectionless - No formal open/close to the connection

• "Unreliable" delivery

- No error recovery

- No reordering of data or retransmissions

• No flow control

- Sender determines the amount of data transmitted

UDP - User Datagram Protocol Communication

Why would you ever use UDP?

• Real-time communication

- There's no way to stop and resend the data

- Time doesn't stop for your network

• Connectionless protocols

- DHCP (Dynamic Host Configuration Protocol)

- TFTP (Trivial File Transfer Protocol)

Communication using TCP

• Connection-oriented protocols prefer a "return receipt"

- HTTPS (Hypertext Transfer Protocol Secure)

- SSH (Secure Shell)

• The application doesn't worry about out of order frames or missing data

- TCP handles all of the communication overhead

- The application has one job

Speedy delivery

The IP delivery truck delivers from one (IP) address to another (IP) address

- Every house has an address, every computer has an IP address

• Boxes arrive at the house / IP address

- Where do the boxes go?

- Each box has a room name

• Port is written on the outside of the box

- Drop the box into the right room

Lots of ports

• IPv4 sockets

- Server IP address, protocol, server application port number

- Client IP address, protocol, client port number

• Non-ephemeral ports - permanent port numbers

- Ports 0 through 1,023

- Usually on a server or service

• Ephemeral ports - temporary port numbers

- Ports 1,024 through 65,535

- Determined in real-time by the client

Port numbers

• TCP and UDP ports can be any number between 0 and 65,535

• Most servers (services) use non-ephemeral (not-temporary) port numbers

- This isn't always the case

- It's just a number.

• Port numbers are for communication, not security

• Service port numbers need to be "well known"

• TCP port numbers aren't the same as UDP port numbers

• Well-known port number

- Client and server need to match

• Important for firewall rules - Port-based security

• A bit of rote memorization

- Becomes second nature after a while

• Make sure you know port number, protocol, and how the protocol is used

FTP - File Transfer Protocol

• tcp/20 (active mode data), tcp/21 (control)

- Transfers files between systems

• Authenticates with a username and password

- Some systems use a generic/anonymous login

• Full-featured functionality - List, add, delete, etc.

SSH - Secure Shell

• Encrypted communication link - tcp/22

• Looks and acts the same as Telnet

Telnet

• tcp/23

• Login to devices remotely

- Console access

• In-the-clear communication

- Not the best choice for production systems

SMTP - Simple Mail Transfer Protocol

- Server to server email transfer - tcp/25

• Also used to send mail from a device to a mail server

- Commonly configured on mobile devices and email clients

• Other protocols are used for clients to receive email

- IMAP, POP3

DNS - Domain Name System

• Converts names to IP addresses - udp/53

- www.professormesser.com = 162.159.246.164

• These are very critical resources

- Usually multiple DNS servers are in production

• Translates human-readable names into computer-readable IP addresses

- You only need to remember www.ProfessorMesser.com

• Hierarchical

- Follow the path

• Distributed database

- Many DNS servers

- 13 root server clusters (over 1,000 actual servers)

- Hundreds of generic top-level domains (gTLDs) -

.com, .org, .net, etc.

- Over 275 country code top-level domains (ccTLDs) -

.us, .ca, .uk, etc.

DHCP - Dynamic Host Configuration Protocol

• Automated configuration of IP address, subnet mask and other options - udp/67, udp/68

- Server, appliance, integrated into a SOHO router, etc.

• Dynamic / pooled

- IP addresses are assigned in real-time from a pool

- Each system is given a lease and must renew at set intervals

- Manage addresses from one location

• IPv4 address configuration used to be manual

- IP address, subnet mask, gateway, DNS servers, NTP servers, etc.

• October 1993 - The bootstrap protocol (BOOTP)

• BOOTP didn't automatically define everything

- Some manual configurations were still required

- BOOTP also didn't know when an IP address might be available again

- Initially released in 1997, updated through the years

- Provides automatic address / IP configuration for almost all devices

HTTP and HTTPS

- Communication in the browser

- And by other applications

• In the clear or encrypted

- Supported by nearly all web servers and clients

Post office Protocol version 3 (POP3)

• Receive emails from an email server

- Authenticate and transfer

- tcp/110

- Basic mail transfer functionality

Internet Message Access Protocol (IMAP)

- tcp/143

- Includes email inbox management from multiple clients

- v4

SMB - Server Message Block

• Protocol used by Microsoft Windows

- File sharing, printer sharing

- Also called CIFS (Common Internet File System)

• Using NetBIOS over TCP/IP

(Network Basic Input/Output System)

- udp/137 - NetBIOS name services (nbname)

- tcp/139 - NetBIOS session service (nbsession)

• Direct over tcp/445 (NetBIOS-less)

SNMP - Simple Network Management Protocol

• Gather statistics from network devices

- Queries: udp/161

- Traps: udp/162

• v1 - The original

- Structured tables

- In-the-clear

• v2 - A good step ahead

- Data type enhancements

- Bulk transfers

- Still in-the-clear

• v3 - A secure standard

- Message integrity

- Authentication

- Encryption

Lightweight Directory Access Protocol (LDAP)

tcp/389

• Store and retrieve information in a network directory

- Commonly used in Microsoft Active Directory

RDP - Remote Desktop Protocol

• Share a desktop from a remote location over tcp/3389

• Can connect to an entire desktop or just an application

• Clients for Windows, macOS, Linux, Unix, iPhone, Android, and others

Network devices

• Many different devices and components

- All have different roles

• Some of these functions are combined together

- Wireless router/switch/firewall

• Compare different devices

- Understand when they should be used

Routers

• Routes traffic between IP subnets

- Makes forwarding decisions based on IP address

- Routers inside of switches sometimes called "layer 3 switches"

• Often connects diverse network types

- LAN, WAN, copper, fiber

Switches

• Bridging done in hardware

- Application-specific integrated circuit (ASIC)

- Forwards traffic based on data link address

• Many ports and features

- The core of an enterprise network

- May provide Power over Ethernet (PoE)

• Multilayer switch

- Includes routing functionality

Unmanaged switches

• Very few configuration options

- Plug and play

• Fixed configuration

- No VLANs

• Very little integration with other devices

- No management protocols

• Low price point

- Simple is less expensive

Managed switches

• VLAN support

- Interconnect with other switches via 802.1Q

• Traffic prioritization

- Voice traffic gets a higher priority

• Redundancy support

- Spanning Tree Protocol (STP)

• Port mirroring

- Capture packets

• External management

- Simple Network Management Protocol (SNMP)

Access point

• Not a wireless router

- A wireless router is a route rand an access point in a single device

• An access point is a bridge

- Extends the wired network onto the wireless network

- Makes forwarding decisions based on MAC address

Patch Panels

• Combination of punch-down blocks and RJ-45 connectors

• Runs from desks are made once

- Permanently punched down to patch panel

• Patch panel to switch can be easily changed

- No special tools

- Use existing cables

Firewalls

• Filters traffic by port number

- OSI layer 4 (TCP/UDP)

- Some firewalls can filter based on the application

• Can encrypt traffic into/out of the network

- Protect your traffic between sites

• Can proxy traffic

- A common security technique

• Most firewalls can be layer 3 devices (routers)

- Usually sits on the ingress/egress of the network

Power over Ethernet (PoE)

• Power provided on an Ethernet cable

- One wire for both network and electricity

- Phones, cameras, wireless access points

- Useful in difficult-to-power areas

• Power provided at the switch

- Built-in power - Endspans

- In-line power injector - Midspans

PoE switch

- Commonly marked on the switch or interfaces

PoE, PoE+, PoE++

• IEEE 802.3af-2003

- The original PoE specification

- Now part of the 802.3 standard

- 15.4 watts DC power, 350 mA max current

• IEEE 802.3at-2009

- Now also part of the 802.3 standard

- 25.5 watts DC power, 600 mA max current

• IEEE 802.3bt-2018

- 51 W (Type 3), 600 mA max current

- 71.3 W (Type 4), 960 mA max current

Hub

• "Multi-port repeater"

- Traffic going in one port is repeated to every other port

• Everything is half-duplex

• Becomes less efficient as network traffic increases

• 10 megabit / 100 megabit

• Difficult to find today

Cable modem

• Broadband

- Transmission across multiple frequencies

- Different traffic types

• Data on the "cable" network

- DOCSIS (Data Over Cable Service Interface Specification)

• High-speed networking

- Speeds up to 1 Gigabit/s are available

• Multiple services

- Data, voice, video

DSL modem

• ADSL (Asymmetric Digital Subscriber Line)

- Uses telephone lines

• Download speed is faster than the upload speed (asymmetric)

- ~10,000 foot limitation from the central office (CO)

- 52 Mbit/s downstream / 16 Mbit/s upstream are common

- Faster speeds may be possible if closer to the CO

Optical Network Terminal (ONT)

- Fiber to the premises

• Connect the ISP fiber network to the copper network

- Demarcation point (demarc) in the data center

- Terminal box on the side of the building

• Line of responsibility

- One side of the box is the ISP

- Other side of the box is your network

Network Interface Card (NIC)

• The fundamental network device

- Computers, servers, printers, routers, switches, phones, tablets, cameras, etc.

• Specific to the network type

- Ethernet, WAN, wireless, etc.

• Often built-in to the motherboard

- Or added as an expansion card

• Many options - Single port, multi-port, copper, fiber

• Ethernet connection

- Onboard NIC may not be working

• Additional connections

- Servers, routers, security devices

SDN (Software Defined Networking)

• Networking devices have different functional planes of operation

- Data, control, and management planes

• Split the functions into separate logical units

- Extend the functionality and management of a single device

- Perfectly built for the cloud

• Infrastructure layer / Data plane

- Process the network frames and packets

- Forwarding, trunking, encrypting, NAT

• Control layer / Control plane

- Manages the actions of the data plane

- Routing tables, session tables, NAT tables

- Dynamic routing protocol updates

Extend the physical architecture

SDN data flows

Wireless standards

• Wireless networking (802.11)

- Managed by the IEEE LAN/MAN Standards Committee (IEEE 802)

• Many updates over time

- Check with IEEE for the latest

• The Wi-Fi trademark

- Wi-Fi Alliance handles interoperability testing

802.11a

• Operates in the 5 GHz range

- Or other frequencies with special licensing

• 54 megabits per second (Mbit/s)

• Smaller range than 802.11b

- Higher frequency is absorbed by objects in the way

• Not commonly seen today

802.11b

• Operates in the 2.4 GHz range

• 11 megabits per second (Mbit/s)

• More frequency conflict

- Baby monitors, cordless phones, microwave ovens, Bluetooth

• Not commonly seen today

802.11g

• Operates in the 2.4 GHz range

• 54 megabits per second (Mbit/s) - Similar to 802.11a

• Same 2.4 GHz frequency conflict problems as 802.11b