1. Computers in Society Week 3: The Internet

2. Preliminaries There are two important things to know before we talk about the internet: Packet switching Standards

3. Circuit Switching Older telephone networks were based on circuit switching, which sets up a dedicated circuit for a communications.

4. Packet Switching Packet switching breaks messages into pieces, which can be routed through the network on different paths. The pieces (packets) are reassembled in order at the receiving computer (host).

5. Standards Technical standards are agreements that specify details of how components or systems are manufactured, behave, or interact. For example, the IEEE has issued a number of standards for buses that connect computer hardware. Conforming to these standards allows manufacturers to build computer cards that can be plugged into almost any computer.

6. Standards (2) Protocols are standards for how systems communicate with each other. The internet depends on the TCP/IP standards. Following these standards allows any host on the internet to communicate with any other host on the internet. Without such universal agreement, we’d have many little networks.

7. An important point: the word internet is composed of two parts: inter, which means between. net, which is short for network. The internet connects many smaller networks (such as the Bucknell campus network) into a much larger network.

8. Early Internet History The history of the internet starts back in the early 1960’s, when researchers at different universities and government laboratories wanted to allow their new computers communicate with each other. J.C.R. Licklider wrote his ideas for creating a distributed network that were developed into a network called the ARPANET.

9. Early Internet History (2) Other researchers at other facilities were developing computer networks as well. In general these networks could not communicate with each other.

10. Early Internet History (3) Email was introduced in 1965. Initially email users had to be on the same system. The ARPANET improved email by allowing users on different systems to communicate. To email someone on a different system, you had to know which computers were connected to which other computers, and to specify a route in the address. For example, an email address might look like this: myhost!nethost!farhost!user@hishost

11. Early Internet History (4) In the 1970’s the Unix system was invented and spread to many universities and research labs. Unix had a UUCP (Unix- to-Unix copy) capability that allowed Unix systems to call each other over telephone lines and transfer files. In 1979 Tom Truscott and Jim Ellis designed the Usenet network to transfer email and bulletin board messages using UUCP. It was a distributed network and content was not centralized. It was the start of recreational use of the internet.

12. TCP/IP In 1982 the Internet Protocol Suite (TCP/IP) was standardized. IP (Internet Protocol) specified the way to communicate between (local) networks. TCP (Transmission Control Protocol) specified how hosts (computers) would communicate with each other over the internet. This laid the foundation for today’s internet.

13. The World-Wide Web The next important step in the development of the internet as we know it was the creation of the world-wide web (www) by Tim Berners-Lee at CERN. In late 1990/early 1991 Berners-Lee developed a network-based implementation of hypertext, text that includes links to other text pages. This is the foundation of web pages.

14. The World-Wide Web (2) In addition to the hypertext implementation, Berners-Lee developed a protocol for transferring hypertext across a network (HTTP, the HyperText Transfer Protocol) and a web browser for viewing the hypertext. The world-wide web began to spread to other universities and research labs.

15. The World-Wide Web (3) In 1993 a group at the University of Illinois at Urbana- Champaign (UIUC) led by Marc Andreessen developed the Mosaic web browser. Mosaic had a graphical user interface. Most previous internet interfaces were text-based. Mosaic became very popular as a result. It led to the development in 1994 of the Netscape Navigator browser, which soon became the most popular browser in the world. Netscape could run on PCs, which introduced the web to the population outside laboratories and universities.

16. The Internet as We Know It By 1995 all the pieces were in place for the development of the internet as we know it. Access speeds were slow, so the content was limited to what could be transmitted at the slow speeds, but the basic capabilities were there. The new internet users began to use it for a range of new purposes. I will talk about three early developments: email, shopping, and pornography.

17. Email As the internet became popular, more and more people began to use email. Email had major benefits because it made communication fast and inexpensive. However, it had two negative effects: People began to send unsolicited messages (spam) trying to sell products or even in some cases trying to steal money. People used email instead of writing letters, and postal business began to decrease.

18. Internet Commerce People also began shopping on the web. Amazon.com went on line in 1995 selling only books. Ebay went on line in 1995. Internet shopping makes life more convenient for shoppers. However, it led to lower sales for so- called brick-and-mortar stores. In the US, first small independent bookstores went out of business, and now large bookstore chains are doing poorly.

19. Pornography The internet quickly developed a large pornography industry. The pornography industry has some very negative social consequences: It has close ties with organized crime, and it exploits people in highly damaging ways. However, because of the needs of this industry and the willingness of many people to pay for it, the pornography industry helped drive the development of many internet technologies.

20. Pornography (2) Pornographers were among the first to use streaming video, live webcams, and secure payment systems. "Nonetheless, it is clear that much of the popular technology of multimedia has been driven by the adult entertainment industry.” The Internet Encyclopedia, Volume 1, Hossein Bidgoli (Wiley)