Lecture Notes: The History of the Internet

Introduction

• Your computer sends a message to YouTube when you click a video.
• The message travels through the Internet, a vast network of interconnected computers.
• This video is part of a mini-series on the history of the Internet.

Early Computer Networking

• During WWII, computers were used to solve complex problems like those involved in creating the atomic bomb.
• Richard Feynman's team optimized problem-solving by using idle computers for other tasks.
• In the 1950s-60s, universities separated terminals from main computers, a precursor to cloud computing.

The Birth of ARPANET

• ARPANET was initiated by ARPA (Advanced Research Projects Agency) in 1969.
• It began as a messaging service connecting UCLA, UC Santa Barbara, Stanford, and University of Utah.
• ARPANET was the first network of its kind and introduced innovations like packet switching.

Packet Switching

• Compared to circuit switching, which required a single uninterrupted circuit, packet switching allowed for multiple messages over the same wires.
• Each message, or packet, had an address label for efficient routing through the network.
• Initial challenges included the need for an updated address list for all network computers.

Expansion and Challenges

• ARPANET grew to include 60 computers in 1974 and over 100 by 1977.
• It extended to Hawaii, England, and Norway.
• Different networks emerged, using varying packet formats.

TCP/IP Protocol

• In the 1980s, TCP/IP (Transmission Control Protocol/Internet Protocol) was adopted widely.
• TCP standardized packet formatting; IP standardized addresses.
• Facilitated easier network interconnection.

Domain Name System (DNS)

• DNS was developed to organize and manage the growing number of hosts and their addresses.
• Introduced top-level domains (e.g., .com, .edu) and second-level domains (e.g., mit.edu).
• DNS servers took over the job of mapping out connections and managing addresses.

ARPANET Decommission and Internet Transition

• By the late 1980s, the Department of Defense ended the ARPANET project.
• The Internet had grown into a global network of universities, companies, and governments.
• Questions remained about who would manage the Internet and public accessibility.

Conclusion

• The video hints at exploring further developments in the next episode.
• Acknowledges the support of SciShow patrons on Patreon for making the series possible.