The Internet: A Network of Networks
What is the Internet? The Internet is the following:
– A flock of independent networks flying in loose formation, owned by no one and connecting an unknown number of users
– A grass roots cultural phenomenon started 30 years ago by a group of graduate students in tie-dyed shirts and ponytails
– Ma Bell’s good old telephone networks dressed up for the 1990s
A new way to transmit information that is faster and cheaper than a phone call, fax, or the post office
Some Internet facts:
– The number of hosts (or computers) connected to the Internet has grown from a handful in 1989 to hundreds of millions today.
– The MIT Media Lab says that the size of the World Wide Web is doubling every 50 days, and that a new home page is created every 4 seconds.
Internet Hierarchy
The Internet has three components: information, wires, and people.
– The “wires” are arranged in a loose hierarchy, with the fastest wires located in the middle of the cloud on one of the Internet’s many “backbones.”
– Regional networks connect to the Internet backbone at one of several Network Access Points (NAPs), including MAE-EAST, in Herndon, Virginia; and MAE-WEST, in Palo Alto, California.
– Internet service providers (ISPs) administer or connect to the regional networks, and serve customers from one or more points of presence (POPs).
– Dynamic adaptive routing allows Internet traffic to be automatically rerouted around circuit failures.
– Dataquest estimates that up to 88 percent of all traffic on the Internet touches a Cisco router at some point.