This first blog is also aimed at MSc Marketing students at Strathclyde who have no real IT background, and some further reading is given at the foot which tries to delve further into technical details while these are mostly written in good prose for the non IT student.
Lecture Notes on The Internet
for Non IT Managers and Students
for Non IT Managers and Students
What is the Internet?
The internet is the physical and electrical data network which now covers large geographical areas on a global basis. To be more precise, the internet exists within what we know as the telephone and data-networks owned by amongst others, phone companies and governments. Since nearly all calls in western countries are digitised now, the internet is just another type of data traffic which is handled in a destinct way on these data-networks.
Further to this, you can say that the internet is the portion of the total capacity, the bandwidth within the diverse cables, which is accessible to data-traffic. This data traffic is itself using special types of communication connection language for example, the exchange protocol called TCP/IP and http. These are agreed methods of picking up the connection, exchaning information and then closing the connection when handling data like web sites, internet file transfer, video streaming, "skype" type calls (VOIP) and e-mail (POP3 and SMPT).
Outside orginisational private networks, very few data cable routes carry exclusively internet traffic. However, the internet's own "telephone exchanges" around the world which route your computer to find, then receive and send information to-and-from remote web sites, are often solely dedicated to connect internet traffic.
Origins and Principles of the Internet and World Wide Web
The internet as we know it originates from two sources: academic networking, ie connections between universities, and governmental security and military networking. It was the latter who decided the internet should be in theory a "web" where no one break in connecting line or node ( city or exchange) would result in loss of data-connectivity between two other points.The idea being that if one line or city got "Nuked" then the information between unaffected cities would find another path to flow around the destroyed element.
So we have both on the one side the egalitarian principles of free flow of information, while on the other side the concerns of the cold war threat of nuclear war in the US and other countries, coming together to create such an efficient means to connect information sources and people.
The structural "redundancy" ie more than one route being available from A to B, has evolved into its own world of money-men and prioritisation of traffic. So for example, the UK driving licence authority in Swansea, pays for a very large amount of bandwidth in the UK fibre optic backbone towards and through south wales, and internet traffic is deprioritised on this route when large transfers of data to and from the Police Force are being done.
Connections between computers have of course a far longer history, as indeed does the utilisation of phone lines for sending binary data signals. Many of the historical means of establishing, permitting and holding contiguity in communications over a network, have been built into the internet, and there is one global standard group of methods for this 'protocol' called TCP/IP which we will come back to.
Economics and Freedom
Some people frequently refer to the internet as being free, and this means that by in large there are no major restrictions in the sharing of information and being connected. Also of course, it does not cost you like a 'post stamp' to get information, and you can read blogs like this and get free lectures over the internet. Some countries and DNS servers associated to them, are not as strict as the USA, EU countries, China and in fact Norway, at controlling criminal activity and illegal information and in particular illegal images. So the wish to have freedom to both publish and access the internet comes with some down sides, and in fact many argue for a stronger police force within the DNS structure.
Internet access is not however free-of-charge. At some point you pay your phone company, or portion of your cable TV fees, to access the internet and they in turn pay for access to national backbones and international connections and networks. (although there may still be some ISPs offering free connecitivity based upon advertising revenue, and as a fee-paying-student, your university may see fit to include internet access).
As the owner of a web site server , hosting web sites, you have to pay for the number of physical lines, the IP addresses and the bandwidth demand coming to and from you. As mentioned in the last paragraph, because there is some degree of horse trading to establish cheap routes within the internet, sometimes your data will be seemingly slow from all web sites in the USA for example, because your national phone company is not paying for larger bandwidth on the fastest route at that point in time, and is diverting you a cheaper, slower route.
In 2009 the advertising revenue spent on the internet in the USA and UK surpassed that spent on traditional media like newspapers and the TV 1 2 3 . If you also factor in that many companies of course use their web address and get free listings on google, then effort, spend and traffic is now vastly flipped over to the internet for many brands, shopping experiences, holiday purchases and of course the huge volume of business-to-business marketing. The evolution of brands who are virtually exclusive to the internet, like Google, Yahoo, Amazon, Facebook and Twitter is worth an entire book and there probably are many good bloggs of course to locate on this topic. However that this media space and these brands command so much economic power is concerning to some commentators and threatening to owners of traditional pay-to-read/view media.
What's the difference, or relationship between the World Wide Web (www) and the Internet ?
..more to be written accurately here The World Wide Web was the area on the internet set up for and allowed to use http " hyper text transfer protocol", ie web site traffic. So originally it was defined IP servers and routers which when a "www" request was sent from your browser, your communication would be channeled through. Now this term is somewhat redundant as this "www" is the majority of public internet traffic, if you exclude e-mail. All internet routers accept and handle http traffic now and for a long time have done, and almost any IP address can host an http web site , in western countries at least.
"www2" was an odd colaboration...more to be written accurately here
Principles of Internet Protocol and Web Communication
How do we know we are on the world wide web and how do computers know to connect to web sites or send e-mail? An analogy we will revisit is that of either an individual householder or one company trying to contact another company in the nineteen forties:
In those old days, to start a call you had to dial a simple number to get to your first manual operator: you could then either ask for a telephone number in a town to be dialled to, or ask for directory enquiries if you knew the name but not the number of the company. We will see that this exact analogy happens today with your computer contacting the DNS computer in your area or country, to ask where a web page called "www. xyz.com" is and what its number is.
In the 1940s, you would be lucky maybe and be connected with just one more operator on the public network before you reached the company's own phone exchange, but in the internet there are often dozens of exchanges between you and the host computer, and worse than that, these change between "calls" and even during calls! Luckily this all happens automatically and with a rather unbelievable high level of accuracy, usually ensuring a seamless flow of information with only tiny delays.
International calls way-back-when, may have been somewhat torturous to get connection, and some were restricted by the governments, like to and from the USSR. International operators would have to speak to each other before you got connected, adding delays. Luckily the internet uses universal languages though between computers to automate all of this, but there are still some restrictions placed on connectivity, in China for example, and to undesirable web sites for those dialling outside of Norway for example.
Now once through to your company, you would then need to establish contact, make your purpose known, ask to be transfered further to a named person at the host's telephone "Board". Sometimes your enquiry is just denied, that person does not exist or you have not the right to get information from them! Or you find that the company is defunct, but a new company pops up to offer a service to you. Eventually you may get to one person, who then just refers you to another internal line and so on.
Using the internet to download and communicate to web pages is very analogous to talking to all those manual operators working at different points in the old phone network, and with good reason: communication has to have protocols, agreed methods of connecting, inter-connecting, intra connecting, passing information and actualy terminating a call. Otherwise computers would not know if a communication was safe or correct, routers ( the telephone exchanges on the internet) would not know where to relay information to, and your host computer could possibly wait around like an operator on a line you have not hung up on would have maybe done 70 years ago.
In this brief lecture for non IT Managers, we will summarise the main protocols and languages used for internet communication and to display information on web pages.
Internet Protocol and Hyper Text Transfer Protocol - TCP/IP & HTTP
Internet Protocol IP; is the primary connectivity protocol between two computers using the internet, which is actually the very near parallel to the old manual operator-phone system above. Being a "Protocol" means that this type of comunication is in agreed way, a defined set of data being communicated to establish connection.
The full terminology is actually TCP/IP (Transmission Control Protocol (TCP)) and this first half provides reliable, ordered delivery of a stream of bytes from a program on one computer to another program on another computer. Wheres, IP, is more focused on dialing up the initial connection. TCP/IP together is the combined protocol that major Internet applications rely on, applications such as the World Wide Web, e-mail, and file transfer.
TCP/IP allows for computers to communicate to each other on the public internet and private ethernets, with defined exchange of small packets of information and there with, handshakes to confirm connection when most often downloading web pages to a client or passing forms back to a server. TCP controls the start, continuation, confirmation and termination of this sending of datapackets.
In essence the primary purpose of IP itself, is to dial between computers through the 'telephone exchanges ' called routers to get to the evenutal server which owns the IP "number" which is ironically called an address.
Now we have 32 bit, x.y.z.w style IP addressing. With the IP address in a given connection. The problem being here that there are only 4 billion IP address combinations in the current xxx.yyy.zz.ww address, but this is soon to be expanded. We are therefore at V6 installment (roll out) because in practice the internet is now full for unique IP addresses, and in fact we are now reliant on people/companies defaulting or giving up on some IP addresses so they can be released for new sites. . This new IP v 6.0 , allows for the IP address in 128bits, a very long internet address protocol, with trillions of new possible IP addresses.
Today though, most internet IP addresses for web sites/ ie servers and often individual user's computers accessed through these servers, begin with zero to 255.xxx.xx.xxx as the first three digits, and most academic univeristies have their own first 4 to 6 digits.
So as a student at a university, the world probably sees you as that one phone number and to send e-mail or direct web page communications is reliant on software to transfer to-and-from you as a unique user.
One IP address can host many domain names, as the primary web server. This server is a computer itself, or a router-computer, like the old telephone exchange at the company in the 1940s. Instead of manual tele-receptionists, this computer is often running a useful bit of software, the most popular brand being called "Apache Server". This sorts out the requests a bit like a mail office or a telephone exchange in an old fashioned company.