How Internet Works
MELISSA DE ZWART: Let's begin with what makes the internet special, for it is special-- possibly the most important invention of modern times. For the 42% of the world's population connected to the internet in 2014, it has changed the way in which they communicate, transact, access education and information, and yet what is so unique and so radical about this technology is that it belongs to and is controlled by no-one-- at least in theory. In theory, the internet relies upon voluntary adherence to technical protocols and nothing more. It is a network of volunteers passing along packets of information, so when the time comes you will pass along packets for them, but this utopian open internet is being threatened by governments and corporations worldwide who seek regulation, control, accountability, and profits. Key elements of the internet remain in the hands of the US government. For example, the domain name system through its dominance over key internet bodies, ICANN-- Internet Corporation for Assigned Names and Numbers-- the body that allocates domain names and controls approval of new domains; and IANA-- Internet Assigned Numbers Authority-- the body that allocates IP addresses and manages the data maintained in the root servers at the heart of the domain name system, enabling us to find one another on the internet. ICANN is a non-profit incorporated body under the laws of California. This was a compromise reached in 1998 when the US-centric nature of domain name allocation became the focus of dispute between Europe and the United States at that time. Other countries control the network connections in and out of their jurisdiction in order to monitor and to restrict content. The internet evolved as an open-ended, collaborative platform, despite the fact that much of the initial work was undertaken using US Department of Defense funding. Internet communication was made to operate in a decentralised mode as distinct from the traditional hub and spoke model of telephony. This meant that if any part of the network was down, the traffic could be re-routed via another route. This model, of course, has meant that there is an absence of centralised control, or a choke-point, making the internet difficult-- although not impossible-- to control from a central point. See the Great Firewall of China. Control over the backbone means control over access. The beauty of this design means that the network is essentially dumb, meaning the intelligence and applications are built on at the endpoint, and this has created the innovative and openness of the internet and distinguishes it from proprietary and closed networks where the intelligence is hosted and controlled in the centre of the network. In the late 1960s, the US Advanced Research Projects Agency funded research into an experimental computer network designed to facilitate communication between remote sites, even in the event of parts of the line being destroyed in a nuclear attack. This meant that the system was not the typical hub and spoke model of telecommunications, with all messages being routed through one central exchange, but rather designed to send the message by whatever means possible, re-routing messages through a series of unpredictable links. Although indirect, the system was effective and hopefully robust. This network, originally known as ARPANET was configured to enable communication between different types of computers --at this stage, all large mainframes on university campuses or military bases-- to allow new modules to be added or deleted and to continue to operate in the event that any part of the line was damaged, destroyed, or captured. During the 1970s, the US government, largely through military funding, encouraged the expansion of academic users on the internet to test its capabilities and expand its uses. It was used as a forum for the exchange of ideas, opinions, and information, and particularly allowing the collaboration of users at remote locations. Over time, the military network was separated from the general internet. By the early 1990s, there was growing interest in the commercial applications of the internet, and commercial users were admitted as paying users of the backbone lines established by the National Science Foundation. The National Science Foundation's acceptable use policy prohibited commercial use of the internet until 1991. It was anarchic, unstructured, and used largely by enthusiasts with no need for guidelines, rules, or regulations. Private use of the internet was offered by commercial providers in a walled garden model. Internet service providers, such as CompuServe, only connected mutual subscribers and provided content managed by CompuServe, excluding access to content offered by other service providers. Three events which drastically altered the nature of the internet occurred in 1991 and 1992. First, the World Wide Web Protocol was developed and publicly released by Tim Berners-Lee from CERN. Second, the Mosaic browser-- later called Netscape Navigator-- facilitating search of the web was developed. And third, US Congress passed a bill permitting commercial activity on the internet. The development of the web effectively destroyed the walled garden model, although new models of walled gardens are now emerging. From this point on, the US government policy, and that of many governments worldwide, was to enable the private sector to drive the development of internet related technology.
How we use the Internet
MELISSA DE ZWART: When most people think about using an online service, they tend to generalise it as navigating or surfing the World Wide Web. While a lot of the content we consume is found on web pages that we access through web browsers, the World Wide Web is just one available service on the internet. The internet, as the name suggests, is a series of interconnected computer networks that carry a large amount of information for a number of network services, including email, internet, phone, audio, video, games, file transfers, and most notably, the World Wide Web. The web is a collection of interconnected documents, or web pages, and other web resources linked by hyperlinks and URLs. Hypertext Transfer Protocol, or HTTP, is the language used on the web for information transfer, yet it is just one of many languages or protocols that can be used for communication on the internet. Protocols could be described as languages, or alternatively, sets of rules for computers. If two computers obey these rules, they will be able to understand each other and communicate. The two primary protocols by which communication is effected between computers on the internet are the Internet Protocol, IP, and the Transmission Control Protocol, TCP. Other common protocols, or languages, include SMTP (email), FTP (file transfer), VOIP (voice), and BitTorrent (peer to peer file sharing). Data that is sent by Internet Protocol is packetised, that is, broken up in to small packets and then sent by means of the IP. Each packet contains a header-- akin to an envelope-- containing information identifying the address or location from which the packet is sent and to which the packet is to be sent. The packet itself contains the data, which is akin to the letter within an envelope. The Internet Protocol communicates information between computers by means of allocating IP addresses to the sending and receiving computers, and then sending the packets of data from one address to another. In most situations, packets of data are not sent directly from one location to another. Largely because each computer on the internet is not connected directly to every other computer on the internet. Rather, each computer is linked to other computers, which are then in turn connected to other computers and so on. This fundamental exchange of information has enabled and increased human interactions through the availability or instant messaging, internet forums, and social networking. Online shopping has exploded as a result of convenience and ability to carry out financial transactions online, and mobile technology continues to advance at a staggering pace. The internet has become such a large part of our lives that we tend to expect our everyday items to be smarter as a result. Whilst this offers further convenience, we often don't consider that all smart products are part of the internet. This has given rise to the internet of things, which extends to anything that can communicate or receive information. Devices we use every day, like our smart phones, cars that send data to their manufacturers, security devices, smart TVs, refrigerators, and even implanted heart monitoring devices send and receive information constantly. Used in the right way, this information can reveal a great deal about who we are, what we do, say, think, and feel, but we aren't the only ones with access to this information, and in this course we will be considering the implications of who else might have access to your data.
No comments:
Post a Comment