1. MA194Using WindowsNT1 Class 7 -- Topics Midterm next week (Don’t’ forget!) A history of the Internet The physical Internet The ‘virtual’ Internet The World Wide Web (WWW) Navigating the WWW HTTP/ISP/FTP/M-O-U-S-E

2. MA194Using WindowsNT2 Regional Networks We know that a local area network (LAN) is something we see in office buildings, college campuses and large organizations. A wide area network (WAN) is often a larger network that just ties these smaller ones together. Thus, regional networks covered large areas of the country like the west coast, the New York area and the Southeastern part of the United States.

3. MA194Using WindowsNT3 The Internet - A history UCB NYSER SURA A B C

4. MA194Using WindowsNT4 Identifying specific machines UCB SURA A B C Machine “B” at SURA Machine “A” at UCB Machine “C” at SURA A.UCB.EDU B.SURA.EDU C.SURA.EDU

5. MA194Using WindowsNT5 Identifying specific machines UCB SURA A B C A.UCB.EDU B.SURA.EDU C.SURA.EDU

6. MA194Using WindowsNT6 Identifying specific machines UCB SURA A B C A.UCB.EDU B.SURA.EDU C.SURA.EDU NYSER B B.NYSER.COM

7. MA194Using WindowsNT7 Too many names! To prevent one site (say, NYSER.COM) from having the same name as a machine at another site (UCB.EDU), the domain is added to the machine name to give us the Fully Qualified Domain Name (FQDN).

8. MA194Using WindowsNT8 Many names, one machine At times, it is useful to have more than one name associated with a given machine. However, we still need to uniquely identify each machine without having to know all possible names, thus there are Internet Protocol numbers (IP numbers).

9. MA194Using WindowsNT9 IP Numbers An IP number is composed of 4 sets of numbers, ranging from 0 to 255, for example: 128.163.128.19 128.1.128.1 128.163.136.2 127.0.0.1

10. MA194Using WindowsNT10 Converting IP #s and names T1.mscf.uky.edu 128.163.132.101 t8.mscf.uky.edu 128.163.132.108 pigpen.ate.uky.edu 128.163.130.10 The conversion is handled by the system using a distributed database called the nameserver or nameservice.

11. MA194Using WindowsNT11 ISP - Internet Service Provider An ISP is an Internet Service provider which is simply an organization (a company, school, etc.) that provides access to the Internet, usually by phone.

12. MA194Using WindowsNT12 Dial Up Access to the Internet One method computers use to connect to the Internet uses an everyday phone line and a modem. One computer (the client or remote end) calls up another computer (the host or ISP end) and the two computers speak via their modems over the phone line.

13. MA194Using WindowsNT13 PPP - Point to Point Protocol The ‘language’ some computers use to establish a connection to the Internet is called a protocol. A few years ago, the most common form was called SLIP for Serial Line Internet Protocol. Today, an improved form is known as PPP or Point-to-Point Protocol.

14. MA194Using WindowsNT14 Chaney@ms.uky.edu An email address is composed of two parts, the user id and the domain name. The domain name may be a machine or it may reflect a domain for machines. The domain section uniquely identifies the machine to deliver the mail to whereas the user id section specifies the individual user for the mail.

15. MA194Using WindowsNT15 Http://www.ms.uky.edu/~ma194 A Universal Resource Locator (URL) has three parts: The service (http://), the machine to access (www.ms.uky.edu) and the pathname of the web page (which is often the name of the user on the machine.)