Greetings, and welcome to Seeseenayy.
Below are the chapter 3 notes for IT. I can't remember what the name of it was, but I was told it was networking and hardware.
IT2 CHAPTER 3
NETWORKING & HARDWARE (Minor)
Monitors:
- CRT - Cathode Ray Tube
- Issues: Heavy, Big, Stores Electricity
- Maintains voltage after unplugging.
- LCD - Liquid Crystal Display
- LED - Light Emitting Diode
Pixels (Image on the right), known as RBG (colors). 
Dot Pitch is known as the distance per pixel.
Resolutions:
- VGA
- 640x480, is 4:3
- SVGA
- 800x600, is 4:3
- XGA
- 1024x768, is 4:3
- HDTV
- 1920x1080, is 16:9
Refresh Rate - The frequency with which a monitor's display is updated.
Refreshes via two methods:
- Interlaced
- Refreshes the odd lines first, then even.
- Non Interlaced
- Starts at the first line, goes to the last.
PC HARDWARE - WHAT TO KNOW BEFORE PURCHASING!
Consider these when purchasing a component...
Motherboard:
- CPU & Form Factor
- Expansion (EXT/INT)
- Amount of RAM the motherboard will hold.
CPU:
- Socket
- Cores
- Speed
- Power
- Heat
RAM:
- Type
- Capacity
HDD:
- Type (SSD/SAS/SATA/PATA)
- Capacity
- Speed
OPTICAL DRIVE:
- Type (SATA/PATA)
- Supported
ADDON CARDS:
- What is needed to add on to? (Video? Sound? Storage?)
- External Storage:
- Type, Connections, Power, Capacity, & Size
- Input/Output Devices
Why use a network?
- Centralized Storage
- Centralized Administration
- Fewer Peripherals (Printers, etc)
Two kinds of networks:
- Peer to Peer
- Client / Server
Measures of network speed:
- Half - Duplex
- Full - Duplex
Mac/IP Addressing (IP Address)
- (IPv4) Logical Address
- Uses 32 bits
- Dotted decimal format.
- 4 groups of 3 digits.
- Software based.
Mac/IP Addressing (MAC Address)
- Physical Address
- Uses 48 bits.
- Hexadecimal
- 6 groups of 2
- Hardware based
Classes of IPv4
CLASS PUBLIC PRIVATE SUBNET
A
- Used for very large networks.
- 0.0.0.0 to 127.255.255.255 10.0.0.0 - 10.255.255.255 255.0.0.0
B
- Used for medium networks.
- 128.0.0.0 to 191.255.255.255 172.16.0.0 - 172.31.255.255 255.255.0.0
C
- Used for small networks like LANs.
- 192.0.0.0 to 223.255.255.255 192.168.0.0 - 192.168.255.255 255.255.255.0
D
- Used for multicast scenarios.
- Not used by us this year.
- 24.0.0.0 to 239.255.255.255
E
- Experimental.
- Not used by us this year.
- 240.0.0.0 to 247.255.255.255
Addressing
Static - IP/SM/DGW/DNS
CHAPTER 3
Network Components
Modem - Cable, DSL, Modulate and Demodulate
Switch - Connects computers. 4 to 48 port switch. It will (mostly) go to a router / WAP.
Router (WAP) - Provides wifi access and connections network.
Multi Purpose Devices - (Wifi) router + switch, (modem/wifi/switch)
NAS - Network Attached Storage
VOIP Phone - Voice Over IP Phone
Hardware Firewall - Faster, physical firewall.
Cables - RJ-45 (Ethernet), Fiber Optic, Coaxial (RG-59)
Cost, Secure, Expansion, Wireless, & Wire
Cable Types:
- Coax (RG-59)
- Twisted Pair (RJ-45)
- Unshielded Twisted Pair (UTP)
- Shielded Twisted Pair (STP)
Cable Ratings:
Cat 5 - 100 MB/s - 100 Mhz
Cat 5e - 1000 MB/s - 100 Mhz
Cat 6 - 1000 MB/s - 250 Mhz
Cat 7 - 10 Gb/s - 600 Mhz
Straight-Thru-Both ends are the same! (Patch Cable)
Crossover - 1 end (T568A/T568B)
- Connect like devices.
Rollover - 1 end (T568B Pins 1-8 & 8-1)
Connectors
- SC
- Snap-in Connector (2.5 mm)
- ST
- Bayonet Mount (2.5 mm)
- LC
- Snap-in Connector (1.25 mm)
2 Types of Cables
Single Mode - Up to 100 km lasers. (Not the bottom one)
Multi-Mode - Up to 2 km LEDs. (--------------->)
TOPOLOGIES
STAR MESH RING BUS
Ethernet:
IEEE 802.1
IEEE 802.11
NAT - Network Address Translation
Static Address:
- IP/SM/DGW/DNS
- Manual
DHCP Address:
- Automatic
Protocols: https://www.grc.com/port_80.htm
- 20 / 21
- FTP
- 23
- Telnet/SSH
- 53
- DNS
- 80
- HTTP / Web
ISP Connections Advantages Disadvantages
- POTS Available Slow
- IDSN Better Speeds Slow
- DSL/ASDL Low Cost Distance from CO
- Cable High DL Speeds Slow Upload
- Satellite Remote Access Very Expensive
- Cellular Mobile Users Dead Zones
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