The Computer Corner: Packet Switching and the Internet

The Computer Corner: Packet Switching and the Internet

Something that has always frustrated me is the fact that most internet users simply fail to understand the concept of packet switching. Of course, it does not help that the convoluted definition of packet switching is “a means of directing digitally encoded information in a communication network from its source to its destination, in which messages may be divided into smaller entities called packets, each of which travels independently through the network in paths based on moment to moment routing decisions made by the nodes through which they pass” (Wikipedia).

 

The misconception most internet users believe is that when they point their web browser to a website such as “The New York Times,” it establishes a dedicated, persistent link between their computer and The Times. That is just not how the internet works.

 

Recently while watching an old 1940s movie, there was a short scene of a telephone operator sitting at one of those old-time telephone switchboards. The telephone operators connected calls by inserting a plug at the end of a wire into the appropriate jack. That action did create a dedicated, persistent connection between the two callers that continued to stay connected until the operator pulled the plug.

 

Imagine how it would work if the telephone operator said, “Look, we have a lot of people wanting to make calls so we can’t have people tying up the circuits when they’re not saying anything. You can say eight words, and then you’re disconnected, but you can call back for another eight if you want to keep talking. We’ll reconnect you as many times as you want, but the limit is eight words per call.”

 

Obviously, that is ridiculous for phone conversations; but this connect-disconnect-connect-disconnect scenario is the way the internet works. Computers are able to handle connecting and disconnecting hundreds of times per minute. Consider what happens when you use your web browser to read “The New York Times.” Your computer connects to The Times to retrieve a news article, and then it disconnects from The Times. The Times sends you the article; then, it disconnects from your computer so that The Times can go on to answer requests from other readers. If you decide to read another Times article, your computer reestablishes the connection. The point is that during the time you were reading the article, your computer was not tying up the server at The Times. That server went about its other business, and so did your computer.

 

This process is fundamentally different from the way the telephone maintains a dedicated connection between two parties until they end their conversation. When connecting to “The New York Times” or any other website, your computer is connecting and disconnecting hundreds of times per minute. This is the essence of packet switching, without which the internet would crash.

 

Charles Miller is a freelance computer consultant, a frequent visitor to San Miguel since 1981, and now practically a full-time resident. He may be contacted at 044 415 101 8528 or email FAQ8@SMAguru.com.