Copyright 2005 Prentice-Hall In a networking course, it seems good to begin with a preliminary definition of the word, “network.” According to this book, “Our preliminary definition of a network is a communication system that allows application programs on different hosts to work together.” This figure looks at networks from the user’s point of view—the only viewpoint that matters in the end. The definition focuses on networks because users only care about applications. The rest is details they don’t care about. The network is shown as a cloud to indicate that the workings of the network should be invisible to users Of course, we have to look inside the network to make it serve user needs. [At the beginning of the 20 th century, an immigrant came to America. He had been told that the streets in America were paved with gold. When he got there, he found that the streets weren’t even paved. Guess who was going to do the paving?]
![Today ’ s Topic - Course Introduction ,[object Object],[object Object],[object Object],[object Object],[object Object],08/31/11](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)