During the late 1970s and early 1980s, the network grew to a few hundred nodes, recalls Ken Vastola. It included most major universities and a number of military research sites. By the late '80s, the network was commercialized, with ISPs making Internet e-mail service available to customers. Experiments with voice and video also began. In the early 1990s, the concept of the World Wide Web was introduced.
Smaller companies obtain their own pipelines through contracts.
Every message is broken into little blocks of data known as packets and sent out over communications links such as phone, cable, or optical fiber lines to machines known as routers. The router reads the address on the packet and sends it on to another router that can get it to its destination. Rensselaer then has its own routers and intranetwork to forward those messages to their ultimate destination. Unlike a letter sent through the mail or a package carried by Federal Express, no one has responsibility for the message from beginning to end, and there are no guarantees, Vastola notes. While organizing a conference, he recently sent e-mails to 12 people around the world.