EOC Summary

1. Who manages and pays for the Internet? Management of the Internet is carried out by a number of nonprofit organizations and user groups such as the Internet Society (ISOC), the Internet Engineering Task Force (IETF), the Internet Architecture Board (IAB), the Internet Corporation for Assigned Names and Numbers (ICANN), and the World Wide Web Consortium (W3C). Each group has different responsibilities and tasks. Currently, the U.S. government (and subsequently the U.S. taxpayer) funds a majority of the Internet costs.

2. How do the Internet’s networking components interact? Individual computers or networks connect to the Internet using Internet service providers (ISPs). These providers are ranked in tiers according to the volume of traffic they carry and the speed at which they transfer data. The connections between Tier 1 ISPs are extremely high speed and are known collectively as the Internet backbone. Tier 1 ISPs are connected to Tier 2 ISPs, which are in turn connected to Tier 3 ISPs. Individuals or corporations connect to Tier 2 or Tier 3 ISPs, which have regional or local focus, respectively. ISPs are connected by T-lines of various speeds depending on the amount of data flowing between them. The points of connection between ISPs are known as network access points (NAPs).

3. What data transmissions and protocols does the Internet use? Data is transmitted along the Internet using packet switching. Data is broken up into discrete units known as packets, which can take independent routes to the destination before being reassembled. Although many protocols are available on the Internet, the main suite of protocols used to move information over the Internet is TCP/IP. The suite is named after the original two protocols that were developed for the Internet: the Transmission Control Protocol (TCP) and the Internet Protocol (IP). Whereas TCP is responsible for preparing data for transmission, IP actually sends data between computers on the Internet.

4. Why are IP addresses and domain names important for Internet communications? An IP address is a unique number assigned to all computers connected to the Internet. The IP address is necessary so that packets of data can be sent to a particular location (computer) on the Internet. A domain name is merely a name that stands for a certain IP address and makes it easier for people to remember it. For example, MyWebPage.com is a domain name and is much easier to remember than the IP address 124.53.111.14. DNS servers act as the phone books of the Internet. They enable your computer to find out the IP address of a domain by looking up its corresponding domain name (which you typed into your browser).

5. What are FTP and Telnet, and how do I use them? The File Transfer Protocol (FTP) enables users to share files that reside on local computers with remote computers. Current versions of browsers enable you to connect to FTP sites on the Internet to facilitate downloading or uploading files to and from FTP sites. Telnet is both a protocol for connecting to a remote computer and a TCP/IP service that would run on a remote computer to make it accessible to other computers. Telnet enables you to take control of a remote computer (the server) with your computer (the client) and manipulate files and data on the server as if you were sitting in front of that server.

6. What are HTML and XML used for? The HyperText Markup Language (HTML) is a set of rules for marking up blocks of text so that a browser knows how to display them. Most Web pages are generated with at least some HTML code. Blocks of text in HTML documents are surrounded by a pair of tags (such as <b> and </b> to indicate bolding). These tags and the text between them are referred to as elements. By examining the elements, your browser determines how to display them on your computer screen. Because HTML was not designed for information exchange, Extensible Markup Language (XML) was created. Instead of being locked into standard tags and formats for data, XML enables users to create their own markup languages to accommodate particular data formats and needs. XML is used extensively in e-commerce for exchanging data between corporations.

7. How do e-mail and instant messaging work, and how are messages kept secure? Simple Mail Transfer Protocol (SMTP) is the protocol responsible for sending e-mail over the Internet. As in most other Internet applications, e-mail is a client/server application. E-mail passes through e-mail servers whose function is to store, process, and send e-mail to its ultimate destination. ISPs and portals such as Yahoo! maintain e-mail servers to provide e-mail functionality to their customers. Your ISP’s e-mail server uses DNS servers to locate the IP addresses for the recipients of the e-mail you send. Encryption software, such as Pretty Good Privacy (PGP), is used to code messages so that they can be decoded only by the authorized recipients.