was not invented by Al Gore… The Internet was not invented by Al Gore…

Who? Vint Cerf Bob Kahn

What / When? Developed the underlying protocol (known as TCP / IP) for the Internet as we know it today in the 1970s The internet was created as part of ARPANET (Advanced Research Projects Agency NETwork) Was created to be a distributed sharing platform for Department of Defense projects that could survive a nuclear attack

Centralized vs Decentralized

Important! The internet is not a network, it is a network of networks interlinked together No one group controls the internet, there are hundreds of ISP (Internet Service Providers) that provide access and help manage the infrastructure that connects

Hot Topics Net Neutrality – ISPs should not be allowed to favor (allow faster access) certain sites (the ones that pay them money) over others; also prevents ISPs from blocking certain sites Removal would allow ISPs to charge users to access certain sites at higher speeds in order to help increase the ISPs bandwith Removal would also allow ISPs to somewhat control what sites a user could visit (like how cable companies have channel packages) Internet Censorship – allows countries / groups to control what is published online as well as what can be viewed Can be used to protect users from child pornography Can also be used to find people that disagree with the government

Addresses on the Internet The internet is really just a bunch of computers all linked together through ISPs (some larger companies are their own ISP) Each computer connected to the Internet has an address (or really multiple addresses) Your router provides you an address Your router is provided an address by the ISP The ISP has an address assigned to them by the Tier 1/2 ISPs Tier 1/2 groups decide their address through peer agreements to allow the exchange of information

IP The Internet Protocol (IP) defines the structure of an internet address or IP address In the old days, v4, and IP address was 4 numbers (each between 0 and 255) separated by periods. The new addresses, v6, are 8 numbers (each between 0 65535 and written in base 16) separated by colons Why switch versions? Due to the number of devices connecting the internet, ISPs are starting to run out of addresses as are Tier 1/2 providers because they have so many connections to other Tier 1/2 providers v6 allows for substantially more addresses than v4

Finding an Address In addition to providing you an address, your ISP also providers you with a Domain Name Service (DNS) that allows you to look up addresses using their nice name (or domain name) like www.google.com Your computer requests the IP address from the DNS and the DNS responds back with the IP address (in the format you requested it)

DNS Providers are Prolific You are not generally bound to use your ISPs DNS There are a bunch of others Google operates one Cloudflare operates one OpenDNS operates one Among many others DNS is also distributed like the internet and there exist peer communication agreements between DNS providers Side Note: this is why it takes so long for DNS changes to propagate, they are literally having to be sent to hundreds of other DNS providers for them to apply

DNS Can Be Attacked Spoofing is when the DNS provider you use is hacked and common websites start responding with the wrong address DOS / DDOS (Denial of Service / Distributed Denial of Service) are attacks when either a website’s server or a DNS provider are sent so many requests that the servers cannot respond quickly enough causing them to crash

Sending Requests on the Internet Requests on the internet are broken up into small pieces known as packets Because the internet is distributed (no central provider), each packet could take a different path to the destination server and they may not arrive in the right order The destination server has to receive all the packets and rearrange them into the order they were sent The path a particular packet follows is determined by a router (not the kind in your house)

Routers Routers are computers that facilitate communication between other computers on the internet When they receive a packet they look at the destination and determine the best path (based on time, congestion, and politics) for that packet to follow Each and every router is configured and operated differently which makes the internet more fault tolerant and open

Routers Gets Lots of Packets Each router has a buffer (or an incoming queue) where all new packets line up to be processed and sent on If the line fills up due to too many packets, the router kills kills any new packets that arrive until some space in the line has been made (extreme checkout lines at Walmart) This killing process is formally known as dropping a packet The IP protocol just sends packets and hopes for the best The follow-up, TCP, acknowledges when a packet is received and if some packets are missing, it will re-request them

Lots of Protocols Build on TCP HTTP (HyperText Transfer Protocol) which transfers HTML (HyperText Markup Language) between servers is one such protocol TCP does not know about security so there exist ways of securing HTTP from prying eyes SSL (Secure Sockets Layer) and TLS (Transport Layer Security) form the backbone of HTTPS These allow packets to be encrypted (not readable without a code which only your computer has) before they are sent to your computer Secure websites are required to be certified by a certificate authority before they can send secure information, in reality this just requires you pay a bit of money every couple of years