Hello everyone and welcome to this series on the Internet. This is probably the most audacious article series I have ever written on this site. An attempt to write a series about the Internet is almost equivalent to writing about a broad topic like Engineering. There is so much to write about and this poses the risk of talking about so many things at the same time without actually giving any useful stuff that would be beneficial to the reader.

That said, there are very many interesting Internet technologies that work together in a coherent and complementary manner. This series is an attempt to explore these key concepts in a manner that would be aid network engineers design more stable networks.

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In this article, we will introduce the Internet and talk about some fun historical facts. We will then move on to describe some of the working pieces of the huge Internet puzzle. Finally, we will wrap things up by discussing the outline for the remaining parts of this series. So let’s get started.

Introduction and History

The Internet is the largest distributed computer network in existence. It is a complex interconnection of autonomous computer networks managed autonomously. Basically, it is a highly evolving yet stable network, which is globally available. Some of its features are:

  • * High availability: The failure of one part of the network does not affect the overall availability of the rest.
  • * Dynamic and stable: Despite being made up of thousands of Autonomous Systems, individual changes in these AS do not affect the overall stability of the Internet. This is due, in part, to the Border Gateway Protocol, the routing protocol which is used on the Internet. Although there are some cases where we experience global instability (like the recent one here – http://www.bgpmon.net/what-caused-todays-internet-hiccup/), these occurrences are far apart and brief.
  • * Service Oriented Network: Essentially, the Internet is still a network. This means that it is used for communication and for providing services. The ability for multiple varied services to run on a common network is what makes the Internet a highly successful distributed network.

Like every other information technology system, the Internet has evolved over the years. Here’s some history about the evolution of the Internet:

  • – 1969 – First Internet work betweenStanford and UCLA was designed.
  • – 1970 – ARPANET: An academic network was created between Stanford, UCLA, MIT, Harvard, UCSB, and BBN.
  • – 1971 – Emails were used on the ARPANET; first network email sent by Ray Tomlinson.
  • – 1972 – CYCLADES: A French edition of the ARPANET was created.
  • – 1973 – The ARPANET was extended to Europe with University College London being the first university in the United Kingdom to join the network.
  • – 1974 – TCP/IP was developed by Vinton Cerf and Bob Kahn. This would prove to be a major invention as the modern Internet Protocol was based on it. This is also the origin of the 32-bit addressing scheme that is still widely used today.
  • – 1982 – The first smiley J was used in communication.
  • – 1983 – Nine years after its creation, TCP/IP was adopted as the standard for the Internet.
  • – 1984 – Domain Name Service (DNS) was developed. Now we can start using names instead of numbers in Internet communication. Hurrah!
  • – 1988 – Internet Relay Chat was created. This is the origin of all things messenger.
  • – 1989 – The World Wide Web was invented by Sir Tim Berners Lee. This was a major advancement in making the Internet a ubiquitous service oriented network. The concept of interlinked hypertext documents is still the most common form of Internet use today!
  • – 1993 – Browsers were invented.
  • – 1998 – Google was created.

I skipped over a lot of details in the history here but we can see the steady advancement in Internet technologies over the years. In the last 15 years, we have seen even more advancements such as cloud computing and the Internet of Things.

Next, we will explore a few high level concepts that make the Internet work. While there are a lot of components that function together here, from a network engineer perspective, the concepts that you should be most concerned with are:

  1. Addressing: With billions of servers on the Internet, one huge problem is addressing these servers in such a way that they are unique. The Internet uses IPv4 (mostly used) and IPv6 addressing (slowly gaining traction over the last few years). IPv4 uses 32 bit addresses expressed in dotted decimal format while IPv6 addressing uses 128 bit addresses expressed in hexadecimal. IPv4 addresses are not nearly enough for today’s Internet devices so we use Network Address Translation to conserve IPv4 addressing. We have explored IPv4 addressing, Network Address Translation and IPv6 addressing in detail on this site before so I would not go into details here. However, if you have any questions about IPv4 or IPv6 addressing, please drop a comment and we would explore your questions.
  2. Names: Numbers are hard to remember and with IPv6 addressing, they are even harder to memorize. So instead of using numbers, we use names. This concept of domain names has been in existence since 1983. We will explore how domain names work on the Internet in a subsequent article.
  3. Routing: Information about destination prefixes on the Internet are exchanged using the Border Gateway Protocol. We will explore how BGP can be used to influence routing and Internet traffic in an article later in the series.
  4. Peerings and Transits: Organizations can connect to the Internet in two major ways: peerings and transits. Usually, transits are used to connect a source and destination together while peerings are directly between the source and destination. These relationships (peering and transits) will be further explored in a subsequent article in this series.
  5. Who owns the Internet? The short answer to this question is nobody. The Internet is a large system of many organizations who have agreed to work together nicely because there is immense combined value in doing so. Different parts of the Internet are controlled by different organizations and they are autonomous in nature. We would explore this concept of Autonomous Systems in more detail as we go along in this series.

Conclusion

The Internet is the most complex distributed networking system in the world, yet it is built on simple networking concepts that have continued to ensure its availability and reliability despite its enormous scale. This article series will peel off the mystical concepts surrounding the Internet from a network engineer’s perspective. I hope I have been able to whet your appetite and that you are excited to read more of this series.

If you have any questions or comments, please do not hesitate to share your thoughts using the comments section. In the next post, we will be exploring Internet connections with Peerings and Transits in detail. I promise not to keep you waiting for too long. Until then, have fun exploring and expanding the Internet!