Introduction to the Internet

Internet

The Internet is a network of networks. Communication between computers and networks on the Internet is handled by a specific set of commands or protocols called TCP/IP (Transmission Control Protocol/Internet Protocol). You generally will not be aware of TCP/IP because communications software provides a high-level interface that handles the protocols. Some networks attached to Internet do not use TCP/IP internally, but they can exchange information by means of gateways.
The Internet is often metaphorically called an "information highway" in recognition of the pathways that connect computers on the net. It is either self-regulating or non-regulated, depending on your viewpoint. No specific agency monitors or administrates the Internet as a whole. Generally, you will find the Internet to be a tolerant, permissive environment that comes closer to representing a sense of global community than almost any social or cultural paradigm in existence today. Some politicians and bureaucrats contemplate anarchy lurking in the libertarian recesses of Internet, and are calling for monitoring the content of information being transmitted. The twin issues of privacy and security over the Internet are being hotly debated. Among other issues unresolved is whether information on the Internet falls under the aegis of print media or broadcast (radio, television) media.

You are using the Internet to transfer information. Electronic mail (e-mail) transfers messages between two parties asynchronously: You send a message to a friend, and later she sends a reply. Although most e-mail activities would not be considered real-time (immediate) communication, there are chat capabilities that allow messaging in near real-time. The metaphor for chat is "push to talk" as you would do when using a CB radio or walkie-talkie. Recently, "push to talk" audio has become available to cybernauts with audio-capable computers.

Newsgroups are similar to e-mail messaging, but newsgroups are not point-to-point communications in the sense of e-mail. A newsgroup is organized around a central theme, and readers contribute comments to the newsgroup. Comments (and replies to comments) are then disseminated by news servers. It's similar to the editorial page in your local newspaper. Some newsgroups are edited (moderated in net parlance), others are not. Unmoderated newsgroups are often forums for copyright infringement, and illicit behavior.

Much information resides as data files stored on various machines around the Internet. The amount of information is so great that you need to use search engines to cruise the net looking for specific topics of interest. Gopher and Archie are two kinds of software used for network searches. Both of these packages are based on client/server models, just like newsgroups. Your local computer runs the client software that allows connections to remote server machines, usually mainframe computers. Both involve protocols for how they operate.

Gopher was originally a menu-based system that allowed connections to remote computers, text-based searching of documents on that computer, and retrieval of documents to the local computer. Archie is a search engine that reaches databases of information archived at many anonymous FTP sites on the Internet. FTP (File Transfer Protocol) is specifically designed for file transfer. Most Archie clients now allow for file retrieval as well as searches. Some client software (Fetch on the Macintosh, for example) are optimized for file transfer and lack the search capability. One important difference between Archie and Fetch is that Archie does not maintain a continuous link to the remote computer as Fetch does. Archie connects only long enough to search a database or download a file.

The World-Wide-Web (WWW) is part of Internet. It, too, uses the client/server model. WWW servers provide information in hypertext. Hypertext contains words or other objects that are links to other words, pictures, or even other servers. Client computers use browser software that properly accesses a WWW site, and then displays a hypertext document in the proper form. Most WWW browsers now have graphical interfaces. Also, other Internet capabilities such as Archie, Gopher, FTP, and e-mail may be run directly from a single WWW browser.

Networks

Access to Internet requires a physical connection between your desktop computer and another computer, usually a mainframe computer, that has either a direct connection to Internet or a gateway to Internet. When computers are connected by physical devices, such as wires (or, in some places, by infrared relays), a network is formed. Not all networks are in the Internet domain.
Local area networks (LANs) provide communication between a cluster or a small group of clusters of computers and other devices on the network. For example, a single academic department on the UNCC campus may have 20 Macintosh computers, three printers, and a shared hard disk array all connected to a LocalTalk network. LocalTalk comprises a set of protocols and hardware that enable all of the attached computers to share data and to print to any of the three printers. It is even possible to install software on this network that will provide e mail within the LAN. Without a hardware router, however, none of the computers on the LAN will be able to access the Internet or even other services provided by the University's mainframe computers.

It is possible for any of the 20 computers to get on Internet via a telephone connection to a commercial Internet provider. This procedure, that requires a modem and software using either SLIP (Serial Line Internet Protocol) or PPP (Point to Point Protocol), allows Internet access but at communication rates limited by the speed of the modem. Home and many business users currently can get Internet services only in this way. Soon, it is likely that the company that provides cable TV to your home will also have Internet available.

Fortunately, most campus users do not have to worry about serial lines to Internet. Most UNCC offices and dorms have fast Ethernet connections that have ready Internet access. All that is required is the appropriate client software.

Accounts, Access, and Addresses

You must have a user account to access most networks. LAN accounts are usually assigned by a systems manager in the department. Computing Services assigns accounts on campus mainframe computers. Faculty, staff, and students may request accounts individually, and the accounts remain active as long as you are associated with the university. Faculty may also request temporary accounts for classes. The appropriate forms are available from Computing Services.

At this point, it is useful to describe how each computer on the campus Ethernet and, indeed, on Internet, is uniquely identified. Desktop computers attached to Ethernet are each identified by an IP (Internet Protocol) number. The IP number is an address; it is expressed as a group of four numbers separated by periods. (The periods are referred to as a "dot" when you are pronouncing an address). None of the numbers can be greater than 256. Each computer is also identified by a domain name. . The domain name has at least two words or numbers separated by periods. A typical domain name has three words. The first word is the computer name, the second is the domain name, and the third is the top-level domain name; you will come across domain names with more than three words.

IP numbers and domain names are registered with a domain name server so that each address is unique. When a new address is registered, it may take a few hours for the information to propagate to all name servers on Internet. Individuals (people, that is) are assigned user names (or login names) when their accounts are set up on a particularly network. When you send e-mail to someone, you must use their complete address in this way:

bighead@email.uncc.edu.