Demystifying Voice & Data -- Part 5
In the fifth in an ongoing series of posts, I explain the Internet Protocol.
As an IT/telecom professional, you are likely to have a good understanding about the theory and principles of voice and data. However, even if you are an expert, at some point in time, you will need to discuss or explain voice, data, and wireless principles to your nontechnical, line-of-business colleagues. The intent of this, and the other posts in this series, is to help you demystify technical concepts for nontechnical colleagues, customers, clients, and so on.
Each article covers a couple of topics, and tries to explain these in nontechnical terms. While the examples and analogies may not always be 100% applicable, they should provide some perspective -- i.e., highlight the differences and advantages.
For my previous posts in my "Demystifying Voice & Data" series, see:
- Part 1: Analog, Switching, Multiplexing
- Part 2: The Digital Advantage
- Part 3: Packet Switching
- Part 4: Data Communications
In this article, I will demystify the Internet Protocol, or IP, as it's commonly known.
The original computer networks were designed with one intelligent computer connected to a number of dumb terminals -- typically an IBM mainframe and IBM 3270 terminals. All transactions were handled centrally by the mainframe, which transmitted results back to the dumb terminals over dedicated, point-to-point connections. Over time, this type of communications evolved to client/server computing.
The analogy in the human body is your brain (host). All nerves (circuits) connect to your brain, and communications constantly occur between your brain and extremities (terminal). When you stub your toe, the data passes along a dedicated circuit (nerve) to your brain. Your brain processes the information, and then sends information back to your toe (i.e., move your foot, start jumping up and down). Your brain simultaneously sends data along respective dedicated circuits (nerves) to other parts of your body -- for example, it sends a message to your mouth to start swearing.
Over time, some of the intelligence (programs) was decentralized to the personal computer, which replaced dumb terminals. Distributed, "peer to peer," network architecture became popular, with its primary advantage being lower costs. The peer-to-peer network is the basis for the IP.
One of the first peer-to-peer networks was the Defense Department's Advanced Research Project Agency network, or ARPANET.
Personal note – In the '70s, as a computer science student at the University of California, Berkeley, I spent countless hours in Evans Hall, the CS building. At that time, you needed to submit your programs in person, on site, and wait for your results, which could take anywhere from 15 minutes to a couple of hours to get. As such, I spent a lot of time hanging around the computer lab. And there, for the first time, I saw a diagram of the ARPANET, which included a node at Berkeley. In the diagram, I could see how computers around the country were linked dedicated circuits.
Remember, this was during the Cold War, and the intent behind ARPANET was to provide insurance in case of a nuclear attack. Instead of having one host computer that could be wiped out, effectively shutting down the U.S. military's ability to respond, a series of "peer" computers could act independently. Should an attack or other problem bring down one or more ARPANET computers, the others would still be able to communicate and operate.
ARPANET's peer-to-peer communications architecture was the forerunner to the Internet. However, when I first saw the ARPANET poster at Berkeley, I thought it was interesting but of limited value. Who would want to link up computers in a network? Of course, I was proven wrong -- for what I had been staring at was a concept that would generate billions of dollars in wealth. Alas, my chance for unlimited wealth and fame was lost.
If the human body worked on a peer-to-peer basis, other "brains" would function in various parts of your body. Stubbing your toe would be addressed at your leg (if your leg had a brain). You've probably used the idiom: That [insert body part] seems to have a "mind of its own." Little did you know this idiom describes a peer-to-peer network.
In 1969, IP's development was a major achievement. In the following decades, businesses adopted early packet switching technologies: asynchronous transfer mode switching, frame relay networks, and ISDN services. By 1991, more than 1 million services were using IP technology. And by the mid '90s, IP became the primary component of the Internet.
Your IP address is similar to your street address. Imagine you are assembling a large backyard structure comprising 50 pieces. Merchants will ship the components via delivery trucks coming from locations across the country. The delivery truck drivers have your street address as their destination.
The same thing happens, for example, when you go to your bank's website and enter your login and password. The bank receives this information and uses it for authentication. It then retrieves your data from its systems, and transmits your account information back to your PC/laptop/smartphone. The information is disassembled, packetized, and shipped over various routes. All packets are sent to your IP (street) address. Once all packets reach your device, they are reassembled and you receive the screen display with your account information.
In the next piece in this series, I will delve more deeply into IP, exploring why it has become so popular and discussing some of its problems (like voice calls).
"SCTC Perspectives" is written by members of the Society of Communications Technology Consultants, an international organization of independent information and communication technology professionals serving clients in all business sectors and government worldwide.