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Notes for Technical Support Fundamental, The bits and bytes of Computer Networking
technical-support's Introduction
- Program/Software: Cooking Recipe
- CPU: Chef
- Brain of the computer
- Communicate heavily with RAM
- Register: Store the data that CPU works with
RAM - Randomly Accessed Memory
- Short term memory
- Volatile, once you close your PC, it disappears.
- Non volatile
- Store BIOS (Modern BIOS => UEFI)
- BIOS = low-level software that
- helps initialize computer's hardware in our PC and get our OS up and running
- run a process called POST (Power On Self Test) to run diagnotic test to make sure the computer is in proper working order
- basic BIOS data about booting your PC (date, time, how you want to start)
- Smaller than RAM, but it allow us to store data that we use often
- Almost the same with RAM
- Like the stuff in our pockets vs food in fridge (RAM)
- L1, L2, L3 => L1 is the smallest and fastest
MCC - Memory Controller Chip
- Connect (aka the bridge) RAM and CPU
- MCC will grab the data from RAM and send it to CPU
- RAM => MCC => CPU
- Long term memory
- HDD VS SSD
- HDD: Cheaper, but a lot of moving parts, prone to damage
- SDD: Expensive, but faster
- Circuit board that hold everything together
- Components: chipsets, expansion slot, form factor (aka the shape and layout of the motherboard)
- Chipsets: Decide how components talk to each other on machine
- Reference
- Kind of like a veins in our body (Maybe like the nerves?)
- Transport binary data
- Sending a voltage through the wire = 1
- No voltage = 0
- 8, 16, 32, 64 wires
- 8 bits = 1 byte
- Transport memory address
- MCC => Address Bus => CPU
- Internal clock that keeps its operational in sync
- When user send/receive data, he sends a voltage to the clock wire to let the CPU know it can start doing calculation
- Clock speed: Maximum amount of clock cycle that it can handle in a certain period of times
- eg. 3.4 GigaHertz = 3.4 billion cycles per second
- Overclocking: Potentially overheat the CPU/uses more power but also make it significantly faster than what it should be
- External devices that we connect to the PC, eg. Mouse, keyboard, monitor
- Not a remote server but just a software that constantly checking whether there is client connect to it
- Public Key VS Private Key
- A set of keys that can only perform either unlock or lock. eg. Public key can only lock but cannot unlock
VPN (Virtual Private Network)
- More sophiscated SSH with a lot more setup
- Allow us to connect to a private network over the internet
- Kernel (Communicating with the hardware, user don't communicate with it)
- Process Manager (Allocate the resources to run the process)
- Memory Manager
- We don't load all the data to RAM at once, but to store it in Virtual Memory (allocated space = swap space)
- We only load the part of the data that is currently running to RAM
- File Manager (Windows: NTFS => REFS; Mac: APFS, Linux: ext4)
- I/O Manager
- Maintain input and output
- load up driver
- handle communication between the devices
- User Space (The part that user communicate with)
- Everything that Outside of Kernel
- Power On => BIOS/UEFI (Including POST) => Boot Device (Bootloader) => OS => Kernel (System Processes + User Space)
- Windows
- Mac OS
- Linux
- Android OS
- Chrome OS
Unicast VS Multicast VS Broadcast
- Done by looking at the special bit (i.e. first octet of a destination addr) in the destination MAC Address
- Example:
- Unicast: For just one receiving address
- Multicast: For >1 receiving address
- Broadcast: To every instances in the LAN Network
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