1. Introduction to the Internet What is the Internet? What is a Network? Use Netscape Mike Menchaca chaka@csus.edu

2. What is the Internet? To understand what the Internet is, we must first learn some networking basics

3. What is a Network? Wire, we use a lot of wire To get info. from one machine to another, one talks & the other listens Vice-Versa.

4. Sharing the Wire Instead of running a wire from every machine to all the other machines, we share a single wire among them One machine talks while the others listen

5. Taking Turns Packets: All machines agree to use the wire for a short bursts of information Protocol: The agreement on how to pass information on the wire The Internet uses a protocol called TCP/IP -or, Transport Control Protocol/Internet Protocol

6. Small Network We have ten machines sharing a wire and each packet takes 1/100th of a second to send If everyone is talking then they can say something every 1/10th of a second

7. Large Network: Too Much Info! But what if you have 1,000 machines on a wire? Then, they can only talk every 10 seconds! This wouldn’t work in the real world

8. Traffic Control To keep down the amount of traffic on a wire, we use routers The router listens to packets on one wire and passes only packets destined for another wire.

9. Routers Thus, routers connect two or more networks together to form bigger networks Internet Cloud

10. What is the Internet? So what is the answer to our original question In addition, each machine on a network has a unique address to identify it For the TCP/IP protocol the address is made of four numbers seperated by periods (130.86.90.1)

11. Domain Name Service However, numbers are hard to remember We like to use names instead of numbers The DNS keeps a record of host names and their respective numbers www.aol.com 152.163.202.70 Domain Name Server