The Internet is now the central medium for the exchange of information of all kinds: starting with the exchange initially simple text messages (SMS, email) on the retrieval of information (images, text, files, information pages, searches, audio and video clips, etc. ) from the World Wide Web to multimedia interpersonal communication (chat, gaming, video conferencing).
The number of “connected” to the Internet computer all kinds doubled annually, and therefore the value of the Internet for all of its users is increasing: there are more and more information (weather, stock, maps, corporate presentations, etc.) and services (online banking, online ordering mail-order companies, information services, search engines, etc.) available, and more and more people can be reached through this medium personally. The global exchange of information on the Internet is increasing every year far more strongly than as the global telephone traffic and exceeds already the total generated by calls “data volume” on Earth. Against this background, current efforts are meant to unify the Internet and telephony underlying technologies and to replace in the long term the telephone network through Internet technologies.
Examples of services that are based primarily on the integration of information from many different sources and the ubiquitous availability of the Internet, are:
- The ground already mentioned Internet telephony, still used exclusively in the private sector for “cheap long distance calls” a few years ago increasingly finds its way into commercial use: companies replace their PBXs, telephone companies are beginning to switch their internal networks to Internet technologies and Internet telephony service provider (Internet telephony service providers, ITSPs) to offer their (business) customers common voice and data services based on the Internet technologies.
Integration with Web browsers allowed to trigger a call by simply clicking on any web page; the email address accepts (wherever possible) the function of the telephone number; and who wants to have a new “supplementary service”, does not wait for its own telephone company, but turns to any service on the net.
- Today you can already make friends and acquaintances against known when it is “online” and beyond his own readiness for communication signal. Linked with telephone services may be in the future prior to the call to determine whether the called party is available at all (or if the attempt end on the answering machine or result in a busy signal would).
Similarly, a person can adjust, at which time they would be accessible from whom and who is rejected or forwarded to the answering machine. Short (personal) office messages or voice prompts are possible as well as automatic call back when the interlocutor resurfaces in the office.
- By combining the geographical position of a person whose stored in the palmtop or Internet-enabled mobile phone “shopping or wish list” and Services- and product range of the vicinity of the person concerned advice may be provided where and what products or services are available – it may be even a price comparison carried out and the cheapest supplier are determined. For directions (or even a complete routing with multiple destinations), possibly including current traffic information and, where appropriate, the parking situation is also conceivable.
- In the fully networked home of the future come next home networks between multiple computers at home then as well as networked household appliances, the inhabitants of the about their current state ( “Machine ready”, “oven 180 degrees for 10 minutes to cook”, “roof window open”) information, but can be just as well (for example, when rain or manually from the office or the Pensions automatically) be controlled.
The notification of police or fire department in an emergency can be realized in this way. The refrigerator, which is informed of the current food ingredients and cooking ideas of residents and automatically purchases over the Internet, is another vision of the future – and it will probably, at least for the really practical use, remain for a while.
From the examples outlined above is also clear that significant risks to privacy of persons in addition to the obvious benefits for the user. In particular, the potential for inadequate protection merging personal data from different sources can be personality characteristics, behavior and consumption habits derive – and exploit natural. Detailed Such considerations are beyond the scope of this qualification unit, which deals with the technology basics of Internet. It should, however, expressly stated that a responsible approach in the development as well as the use of Internet technologies is indispensable: not everything that is technically feasible is also content really useful, economically viable or socially responsible.
An essential prerequisite for the approach outlined above scenarios are on the one hand, the global coupling of the various information resources, on the other hand, the ubiquitous availability of the communication medium Internet for the user: in the workplace, on the move, at home. After the Internet is increasingly seen in the office and at home as a matter of course, the business is increasingly in the focus of interest. Already the first airlines offer Internet access to the plane, some of New York taxis are holding now an Internet connection for the passenger ready (as perhaps the ICE in the not too distant future). Airports and train stations as well as central public spaces (pedestrian areas, shopping malls, cafés) are cross-linked. For the better (and especially quasi-permanent) home connectivity ensure always-on technologies (“always on”), as they are now available in the form of DSL and cable modems for the private user. In addition to this new technology allow for in-home networking and global connectivity of all possible systems – regardless of where they are placed in the home or in the home, whether they appear as networked devices or are not recognizable as such.
The underlying today’s Internet technology is designed precisely for this purpose: namely to link various networks in order to allow cross-network communication between any computers: internetworking. The central module is the Internet Protocol (IP), which is responsible together with various other devices for the transmission of information between two or more communication partners. In addition, available on the Internet a number of components that enable the operation of the network and contribute to its usability. Together, these communication platform of the Internet. Finally, there are a variety of applications that use this communication platform and offer user-visible services, such as the Web.
In this qualification unit just mentioned technologies are described, which is based on the Internet, as well as the underlying Internet concepts. On the one hand an understanding of the architecture of the Internet is to be conveyed, on the other hand, the essential building blocks to be described in their operation and their interaction.
However, before we specifically turn to the Internet technologies, we want to enter in the first two learning units of this qualification unit on the basics of data communication in order to convey the major concepts as well as the basic concepts of any communication – and thereby the necessary understanding of the later recurring problems communicating on the Internet to awaken. Therefore we start with two examples from everyday life, which seem to have little to do at first sight with the Internet, on closer inspection, however, provide a good introduction to the problem areas of communications technology and their solutions.