- What Is a Network? What Is Networking?
- Why Build a Network?
- How Networks Are Put Together
- The Network Architecture: Combining the Physical and Logical Components
- Two Varieties of Networks: Local and Wide Area
- How the Internet Relates to Your Network
- Connecting to the Internet
- Why the Internet Matters
- Intranets, Extranets, and internets
Why Build a Network?
If we’re happy with receiving or sending information by hand, we can resort to the postal service. But hard copy correspondence is called “snail-mail” for good reason. It’s far too slow in today’s accelerated world. By the time a letter arrives, its contents are often old news.
- In contrast, a computer network enables faster communications between parties. In so doing, it leads to more efficient use of time.
- By sharing electronic data among perhaps thousands of people, a computer network encourages (requires!) the use of standard policies and procedures. After all, our personal computer and our text-proficient cell phone have no inferential power as we humans do. We can just respond with, “Say again please,” if we don’t understand a transmission. But a computer network must be laboriously programmed to perform this one simple task. However, and once again, these standardized procedures lead to more efficient communications.
- Networks provide backup and recovery support for our data. If the postal service’s mail truck breaks down, our letter might be delayed for a day—at least. Not so for a computer network. It’s designed to provide near-instantaneous recovery from a failure—all without a loss of a single character or number in our (electronic) mail.
- “I’ve lost that file!” “I’ve lost the letter!” These lamentations are no longer true with computer networks. If networks are properly designed, it’s easy to store copies of our data. Be it mail, photographs, files, or video, we can keep copies safe and sound on another computer in another part of the country—if we take the time to instruct the network to do so.
- Shared resources lead to less expensive communications. Take the Internet, for example. It’s an expensive public network (in reality, millions of interconnected networks), but we use it for a few dollars a month, and its performance is such that we might consider it our own private network. That is, we think we have this network for ourselves, but we don’t. A term to describe this fine service is virtual private network.
As many reasons exist for using computer networks as there are people sharing them and organizations building them. One person might have a bunch of computers at home—one for her, one for him, several for the kids. She may want to hook all the computers together so the family can have a common calendar and email, which, as we know, the kids will more readily read than the note on the fridge. Another person may want to connect his small office or home network to the Internet to use the Web. Yet another person in Texas may to play Texas Holdem with his friends living in New Jersey.
Computer networks have transformed the way we work and play. For better or worse, they’ve changed our lives. I trust that you think the change is for the better. I do. But we’ve said enough about why we use computer networks. Let’s now see how they’re used, and more to the point, how we can use them to improve our personal and professional lives.