2. You and the Internet


Introduction

neighborhood and network

The Internet is a Network (of networks) of Computers πŸ“‘

Think of your neighborhood. How is it organized?

neighborhood
  • houses connect to each other through shared interfaces
    • electrical grids
    • sewage
    • waste management
  • each house has its own address
  • clusters of houses comprise neighborhoods
  • apartment buildings can be considered neighborhoods with each floor being a cluster of condos, have one main entrance, and maybe a front desk, to handle traffic in / out of the building
  • neighborhoods help cities manage how resources are distributed
  • some neighborhoods are very densely populated :house_buildings::house_buildings::house_buildings:
  • some neighborhoods are spread out 🏠🏜️🏜️🏠

Interfaces of the Internet

network diagram

the internet is organized in a similar way to your neighborhood

  • networks generally have one Network Access Point (NAP) to handle traffic in / out of the network
  • networks facilitate traffic (data) across the internet
  • some networks are densely populated πŸ’» πŸ’» πŸ’»
  • some are sparsely populatedπŸ’» 🏜️ 🏜️ πŸ’»

peripheral interfaces

  • clusters ( or modules) of computers, called nodes, comprise networks
    • these network computers are not designed to be used like your personal computer
    • they are referred to as nodes to help clarify the distinction

software interfaces

  • computers connect to each other through their network interfaces
    • ethernet 2.0
    • IEEE 802.11
    • VPC / VPN
  • each computer has an address

mailboxes

When you mail a letter, you must properly address it, add correct postage, and any other rules or protocols set up by your region's mail delivery system or it will be returned.

Networking nodes and modules isn't all that different (I mean, it is! But you get the idea )


Neighborhood health relies on people getting along, usually through some set of rules every neighbor agrees to follow

  • some neighborhoods have HOAs
  • some neighborhoods have community boards
  • some employ neighborhood watch shifts
  • some have regular block parties
neighborhood and network

neighborhood and networkneighborhood and networkneighborhood and network
three diagrams demonstrating progressively complex network systems

Network health relies on good node-to-node communication, and good module-to-module communication

  • each network has at least one Network Access Point (NAP)
    • i.e. a front desk
      • outsiders must talk to the front desk of your apartment building in order to talk to you
  • these connections need to agree on basic rules called protocols that every node and module (cluster of nodes) must follow
  • network protocols ensure that a connection between any two nodes will be available, reliable, and consistent 24 / 7

The set of rules that comprise how the internet works are called Internet Protocols (IP)

  • Each node connected to the internet must have its own IP address so other nodes can find it.

Data and the internet

Twin Datas from Star Trek

Internet data is about connectivity

  • data travels through the internet from one node to another until it reaches it's destination IP address.
  • think of it as the difference between a letter and the entire postal system
    • what is the "data" of a letter?

      • journal entry? βœ”οΈ
      • to / from addresses? βœ”οΈ
      • stamp? βœ”οΈ
    • what is the "data" of a postal system?

      • routes? βœ”οΈ
      • zipcodes? βœ”οΈ
      • letter / package volume? βœ”οΈ

data is handled in two basic ways on the internet

neighborhood and network

data in motion πŸƒ

  • data is broken down into packets
  • data reassembles when it reaches its destination

data at rest 😴

  • some data is cached at NAPs
    • your building's front desk "caches" info for all tenants
      • i.e. "Notice to all tenants: there will be..."
  • service outages ☠️
    • nodes go offline
    • routers fail
    • congestion πŸš₯
  • data packets are cached in the nearest node
  • networks spin back up, and data packets resume travel
  • errors often occur when systems shutdown mid-execution

Time and the internet πŸ•š

network time diagramnetwork time sync diagram
  • Network Time Protocols (NTP) help networks sync time

    • one node is cast as the layer 1 source of truth
    • other nodes that sync with this node become layer 2 nodes
    • other nodes that sync to layer 2 nodes become layer 3 nodes, etc.
    • accuracy to 1ms
      • that's a long time for modern networks
      • if I have $100 and a super fast connection, I can wire you $100, my friend Bob $100, and my other friend Alice $100 - all before my bank realizes what happened.
  • Your internet relies on whatever the network thinks is the correct time.

    • it assumes the time given it by the network is trustworthy

We need to adjust and re-adjust how our computers measure time

  • Y2K
    • Date formatted as YY instead of YYYY
      • '97...'98...'99...😨
  • Y2038
    • Unix time
      • counting the seconds since 1970
    • Imagine if a system could only count to 2,147,483,648 seconds
      • and resets to zero each second after that...
      • we don't need to imagine it - just wait until 2038

Your Relationship with the Internet

the 90s web

Identity

early internet comic
  • Your IP Address is your identity
    • I may not know who you are, but I know where you're calling from

Ownership

Who owns the internet? Not you!

internet ownership
  • you don't own your apartment building or the roads and sidewalks that make it accessible

  • businesses built their own networks and eventually agreed to connect those networks

  • network owners can take a node or entire network offline

  • your computer's access to the internet is entirely governed by centralized networks

    • You are at their mercy
    • You pay for a service, not a right
  • you have no say in how internet protocols are decided


Structure of the internet πŸ›οΈ

neighborhood and network
  • The Internet is distributed

    • It doesn't go down when one node or network goes offline
      • your internet going down isn't the same as the internet going down
  • The Internet used to be decentralized

    • One computer connected to another computer, and so on
  • The Internet quickly became centralized

    • each network has one access point (NAP)
      • one door to open or close
      • one point of failure for the entire network
    • network owners in control
      • access decided by a small group of people
      • vast distributed systems with numerous access points still controlled by a a handful of decision makers

Quiz

Edit this page open in new window
Last Updated: 5/9/2022, 3:20:19 PM