internet

26
The Internet Yesterday, Today, Tomorrow by Erik Bosrup Nv3b 1998

Upload: prakash-charry

Post on 24-Nov-2015

15 views

Category:

Documents


0 download

DESCRIPTION

Internet

TRANSCRIPT

The Internet - Yesterday, Today, Tomorrow

The Internet Yesterday, Today, Tomorrow by Erik Bosrup

The Internet

Yesterday, Today, Tomorrow

by Erik Bosrup

Nv3b 1998

Jakobsbergs GymnasiumSpecialisation Project

Computer Communication

Preface

When I started with this project my aim was to learn about TCP/IP and how the Internet works in general. Once I got into the huge amount of information that exists about Internet I discovered that I wasnt really interested in the technical terms and exactly how everything works. Instead I decided to write a text that mostly anyone with slight computer and Internet experience could read and understand most of.

While going through the information I also found papers about new standards and projects that I saw relevant to the future development of the Internet. This made up my project question, how will the Internet handle the future? Or perhaps how will the future handle Internet? To explain the coming generation Internet one must know how the Internet once started, how it works today, who controls it and many other things. This matched my interest in finding out how the Internet works with my plans to examine the nets future. All of these things make up one big mix of information, its not too detailed, many things are left out. My goal was to get a general feeling for what the Internet is and what it will be.

Table of contents

2Preface

Table of contents3Internet Technology5Universal Resource Locator5Application Protocol5Host5Domain5Top Level Domain5Domain Name System6Transmission Control Protocol6Transport protocol layer7Internet Protocol7Routing7Subnets7Ethernet8Physical protocol layer8Address Resolution Protocol8Putting it all together8Past the basics9ICMP9UDP9Ports9Internet history and organisation10Dawn of internetworking10Controlling the Internet11Internet Architecture Board11IETF and IRTF11Request for Comments11Internets Future12Next generation Internet12Security12Multicast and Quality of Service13Neighbour Discovery13Forwarding13Transition146bone14New domain names15Future connections15Fixed connections15Mobile connections16Wireless Internet16Conclusion18List of references19

Internet Technology

Internet is not one big network. As the name claims it is inter-net, thus a network connecting networks. This is important to know as it is the base of the Internet foundation. When you logon to your local Internet provider, you connect to their network, which is connected to many others. This is the strength of Internet, if one network malfunctions, the other can function normally without it.

Universal Resource Locator

Most people use the Internet merely for World Wide Web browsing and e-mail. To explain how the Internet works we will start by using a sample connection between a browser and a server. There are many ways to find an URL to visit, they can be found in magazines, newspapers, they can be bookmarked or they can be embedded in other documents as links. However they all consist of the same major parts. Lets look at an URL and sort out whats what in it. We will work with http://www.internet.com, its a site for and about the Internet. The easiest way to understand URLs is to split them up into part, like this:

protocol://host.domain.tld

Application Protocol

Today everyone knows that a text starting with www is a World Wide Web address, this is not completely true. Actually it is the http:// part of the URL that specifies that we want to connect to the part of the server that handles the Hyper Text Transfer Protocol although if we try to connect to an address starting with the www prefix our software assumes it to be http. The http protocol is the Internet standard for exchanging HTML files between clients and servers. HTML or HyperText Markup Language is the language used to layout pages so they may contain text, pictures, multimedia and Java among else. In this case we are acting as a client since we are requesting a document from someone else. Other than http there is also a secure encrypted version of http, called Secure HyperText Transfer Protocol (https://) and the File Transfer Protocol (ftp://) among many others. So the first part of the URL, the protocol tells our software how we want to connect to the server and what kind of reply we are expecting.

Host

Next comes the host. A host is a computer that is connected to the Internet. When you use your modem to connect to your local ISP (Internet Service Provider) or LAN you will also become a host. However only certain computers have hostnames that works in an URL. If you connect through an ISP you will not get one that can be used in URLs.

Domain

Since the communication between hosts is based on IP (Internet Protocol) addresses and the computers themselves dont know where on the net an URL is to be found, they can only say I want to talk to host 130.92.112.96. For this reason we have domains. A domain is a way for us humans to remember a location on the Internet. The computer must translate the domain into a number in order to make contact to the host.

Top Level Domain

The top-level domains also exist to make it easier for us humans to find our way on the Internet. The tlds are provided so that domains can be sorted into categories and countries. Countrywise they are sorted after a two-letter country code standardised by ISO. The category domains include top level domains like .com for commercial usage and .edu for education.

.arpaARPA specific domains

.comCommercial organisations

.eduEducational institutions

.govUnited States government agencies

.intInternational organisations

.milUnited States military

.netNetwork providers

.orgNon-profit organisations

.adzwCountry specific domains

Domains can be mostly anything, different TLD registrars (the organisation that manages the registry) have different rules for registering domains and as long as you follow their rules and domain names rules found in RFC 952, 1035, 1123, you are free to use your imagination. (More on RFCs later on.)

Domain Name System

Because the hosts only can find each other by IP address in the same way that US Mail needs zip codes to find the correct receiver, there must be a system to convert our easy to remember URLs to address that the computer can use. This system is called the Domain Name System (DNS). In the early days of the Internet there werent many hosts on the net so every computer connected had its own file with all the domains and their corresponding addresses. Today however with millions of hosts connected this system wouldnt be very efficient. When we want to find our host, www.internet.com, we contact a computer that we do know the IP address of. This server is called our root dns server. We ask this server where we can find information about .com domains. The dns server then gives us a list of .com domain name servers. Our computer now selects one of these servers, contacts it and asks it about internet.com. Just as with the root server we get a list of servers handling that domain. This is how it continues until we know the IP address of www.internet.com. In general the Internet software is smart and remembers common servers, and can that way skip one or two of the domain name servers, making the communication faster and less transfers necessary. Now our computer software is ready to make the actual connection to the host.

Transmission Control Protocol

The communication over the Internet is made up of layers. This way many different types of computers can talk to each other by varying methods. Another feature of it is that every piece of software doesnt have to re-invent the wheel, for example, when we use Netscape Navigator in Windows95 to connect to www.internet.com, it will use a piece of software built-in to Windows95 called Winsock. Winsock will then handle the communication such as send and receiving data and looking up domains through the domain name system. Our browser will just tell it what to do and it will do it. Of course its not only browsers that use Winsock, mostly all Windows95 Internet software such as e-mail clients, ftp clients and newsreaders use it. The same way that Windows95 has Winsock most other operating systems have something similar that has the equivalent features.

Weve been over the application protocol layer, it was the protocol that described how two applications talk to each other, like how the HyperText Transfer Protocol transfers the html documents used to layout webpages.

Transport protocol layer

Usually when Internet communication is discussed people talk about TCP/IP and how all the information over the Internet is transferred over it. This is not completely true, although most information goes by TCP (Transmission Control Protocol) there are others. The applications that are communicating decide which transport protocol they are going to use based on the standard that is set for the data that is to be transferred. Applications like browsers and file transfer clients use TCP while transfers that need more speed, like audio and video streaming, at the cost of reliability use UDP (User Datagram Protocol).

When applications talk to each other over the Internet, like when you look at someones homepage, they do they do not take part in the actual sending and receiving. This is where the transport protocol layer comes in. The application tells the transport protocol what to send and where to send it and then in the case of TCP it is up to the transport protocol to make sure that everything gets sent and that everything arrives in the same state that it was sent. And if anything goes wrong it is also the transport protocol layer that handles it by re-sending. The transport layer also splits that data into smaller pieces, if you want to send someone a two-megabyte file, it cant all be sent at once, so the transport protocol layer splits it into smaller chunks.

Internet Protocol

The Internet Protocol (IP) layer gets the datagrams (the parts of a file that has been split up) from TCP (or whatever transport protocol that is being used) and adds some of its own information and does the actual logical transfer over the Internet. Simplified this can be described as if TCP makes sure everything goes through, while IP actually makes it happen.

IP only does the logical transfer, this might sound weird but it isnt. Since Internet spans over many different types of networks such as Ethernet and Token Ring which all have their own way of communicating there is a need for a layer that can work on top of them all. The Internet consists of many networks connected to each other, some networks might have connections to many other networks while others only have one route out to the rest of the Internet. It is the Internet protocols job to find out how to move the data between the different networks.

Routing

Finding out how to move this data between networks is called routing. Where two networks are connected to each other there is a router or a gateway, these are used to move data between the two networks. So what IP has to do is to check if the target computer is in the same network and if so, just send it away. If not it must find out to which route it should take. For this it uses a routing table, in it there is a list of IP addresses and to what gateway they should be sent. If there isnt an entry for the target IP, it is sent to the default route. The default route is the gateway that is most likely to be the correct one. When it knows where to send the datagram, it does so and its that networks responsibility to get the information to the correct computer or onwards to another network.

Subnets

Networks on the Internet are called subnets, a subnet can also have its own subnets. A large university can for example be a subnet of the Internet and have subnets for each faculty. The purpose of making small networks it to stop one malfunctioning hardware device from stopping the entire network. This is a part of the overall Internet strategy, there should always be a way out. If on connection goes down there is always another. When IP decides if a host is located within the current subnet it looks at the IP address and analyses it.

All the computers connected to the Internet must have its own IP, and because networks have different size, i.e. number of hosts, there are different network classes. The system is constructed in such a way that Class A networks may have many subnets and hosts, while Class B networks fewer, and the class system ranges down to smaller and smaller classes each with fewer hosts. All the networks connected have been assigned one or two network ranges from a central authority in which they can decide what computer gets what number. A company that requests X amount of IPs might not have the need for an entire Class B network can then be assigned two or three Class C networks. The point of not giving out more IPs than necessary is due because the Internet is starting to run low on IPs.

Ethernet

Ethernet is a very popular and widely spread type of Local Area Network. The most common form of Ethernet is called 10BaseT, which denotes the maximum transmission speed of 10 Mbps using copper twisted cables. Recent enhancements of Ethernet bumps the speed to a maximum of 100 Mbps, this system is called 100BaseT.

Physical protocol layer

Ethernet is the physical network. Here we have computers actually connected to each other by cables and wires. Since IP was made to travel over many kinds of networks, it has its own addressing system, the IP numbers. At the physical layer of the network, IP addresses do not mean anything, Ethernet and all the other networks have their own way of finding the correct hosts.

When Ethernet was designed one of the goals was to make sure that two computers could not share the same address. Because of this every Ethernet network interface card (NIC) sold has its unique Ethernet address consisting of 48 bits (a bit is either 0 or 1), all the Ethernet manufacturers has to register with a central authority that is monitoring this.

Address Resolution Protocol

Ethernet works in the same way as a big party line, what one says, everyone hears. But just like you do not listen to what everyone says on a party line, your Ethernet system will only listens to data directed to it. To find the corresponding Ethernet address for an IP address (as they have nothing in common), your system will send out a broadcast to which all the systems on the local network will listen, asking if anyone is assigned to that IP. This system is called the Address Resolution Protocol, commonly called ARP. When the system that has that IP hears your request for its Ethernet address, it will reply and the two computers can now talk to each other. It would be very bad for the network performance if this had to be done every time two computers try to make a connection, because when its done all other communication is halted. Instead your system will save the information it knows about other hosts in memory for some time to speed things up.

Putting it all together

You probably noticed that there are many protocols needed for Internet communication and its not always easy to understand how they work together. We will take a small example as a summary and show what each protocol will do.

We will again use our browser example, lets say that you have requested a small text document from www.internet.com and the server sends it over to you (mycomputer.network.se). First of all the server will add information about what is sent in the HyperText Transfer Protocol, discussed earlier. This will tell your application what data the packet is containing. Next TCP will take all that information and add its own headers to it and send it all down to the IP level. IP will also add its own headers, as each protocol layer only understands its surrounding neighbours. Ethernet will not understand TCP headers and HTTP will not understand IP headers. The IP layer will now found out how the packet is to be sent, and its most likely through Ethernet so it passes it down to Ethernet. Once the Ethernet package reaches mycomputer.network.se, Ethernet will remove its headers and send it back up to IP. IP will the do the same and give the information to TCP. As you can read from its name, Transmission Control Protocol, TCP check the information so it hasnt got corrupt while transferred, if so it asks the server to send it again. If its all right it will remove its headers and give the information to you browsing software that removes the HTTP headers and you can now see the text file in your browser!

Past the basics

Internets smart layering system might make it seem as if it is easy for the different layers to perform its actions. For users and most application developers its both easy to use and develop Internet software as most of the technical parts of it is built-into modules that can be easily adapted in many programming and application environments. Behind all of this it isnt such a simple matter. As we discussed earlier large files have to be split into smaller pieces so it can transferred easily. This wasnt completely true. Almost everything that is transferred must be split, or fragmented. Every physical network type has its own limit on how big packages it accepts and if a larger one arrives it must then handle the splitting and re-assembly, that on packages that might already be split. Sending out too large packets can then of course make Internet transfers slower as hardware on other places must work, besides the increased traffic volume this generates.

ICMP

Internet has many other protocols than the ones we have discussed here so far. ICMP or Internet Control Message Protocol would probably be described as Internets error reporting protocol. If a packet of data takes too long to deliver, an ICMP message will be sent to the sender telling what happened. Also if a system tries to transfer some data to a network outside the local one through the default router and that router has been told there is a better way to the target, the source will receive a reply stating so. The Internet Control Message Protocol really is what its name says, a message protocol for reporting errors, it doesnt find errors itself.

UDP

We talked about UDP, User Datagram Protocol before and we said it was less reliable and faster. It is less reliable because its headers are smaller and it has fewer features to verify that the information transferred is correct. While TCP is what is called a connection protocol, in other words both computers talking respond to each other data so they both know if everything worked, UDP is connectionless. This means that in for example an audio stream from a live radio show is sent to the listener just like in real broadcast radio. Ready or not, were transmitting now. Its basically up to the listener to make sure hes ready to receive. This of course means loss, some data will not reach the listener and that is what makes is less reliable but faster. UDP itself doesnt have any error checking but the application using the protocol may, it is however then easier to use TCP that has it built-in.

Ports

When TCP receives data from IP, it does not directly know how it should be sent to the application layer. Many Internet applications might be running so there must be a way to find out what application wants what. This is done by using ports. When we connect with our browser to www.internet.com, our software knows we want to connect to the HTTP part of the server since we are using the world-wide web (it can also be specified by typing http://www.internet.com:80). To make sure the server knows were requesting an HTTP document we add the standardised port 80 to our request. With the request we also add the port we want the server to communicate with us through, this can be any free port. This way the two computers TCP software can get the data sorted out correctly. Different types of transferred data uses different ports that are standardised to make sure there are no clashes.

Internet history and organisation

Dawn of internetworking

The groundwork for Internet was created as early as in 1957. That year USSR launched the first satellite, Sputnik. To establish lead in military science and technology the US Department of Defence formed the Advanced Research Projects Agency, commonly known as ARPA. Later in the 60s, ARPA started to study networks and how it could be used to spread information. In 1969 the first few networks were connected. The first system to send e-mail across a distributed network was developed 1971 by Ray Tomlinson and the telnet (allowing users to login on remote computers) specifications arrived one year later. The first drafts for a networked called Ethernet were created in 73 and a year later there was a detailed description of the Transmission Control Protocol. The Usenet newsgroups were created in 1979 and in 1982 Department of Defence declared TCP/IP to be standard. At this time the number of hosts connected was very low, in 1984 it broke the 1000 boundary. Three years later that number had changed to 10000, but we are still far from the Internet explosion.

Most of this all happened before computers were widely spread, IBM released its first PC, based on Intels 8088 processor in 1981. The Pentium processor family that currently is being phased out arrived in 1994. The users connected to the Internet at this time were researchers and students, connected by university networks.

A worm that infected computers on the Internet with a program that took up system resources (like memory) created a need for some sort of team that would try to find solutions to make such issues less dangerous. The team was called Computer Emergency Rescue Team (CERT). They work by writing advisories and reports on how to avoid problems.

What most people tend to define the Internet as, is the web. The World-Wide Web standard was created in 1991 by CERN and the predecessor to Netscape Navigator, Mosaic saw light two years later. Common people started to get Internet access in 1994-95, its around those years the numbers of hosts, domains and networks started to increase rapidly. Yet only a small amount of the earths population is connected.

The so-called browser war between Microsofts Internet Explorer and Netscapes Navigator started in 1996 when the two companies released their 3.0 browsers. When this is being written there still isnt a winner but Netscape has been forced to make its browser free (Microsofts has always been), including the source code. Perhaps the US Justice Department will prevent Microsoft from giving its browser away, perhaps they will split the company into pieces. At least it shows the future importance of the Internet when Microsoft embeds its browser into the core of its operating system.

Controlling the Internet

When we look into how the Internet is controlled today, we have to have in mind that when ARPA created the network for more than 25 years ago, they did not intend it to be used the way it is used now, nor did they expect this amount of users. The managing organisations have been created along the way and there are no exact jurdistictions on who controls what.

Internet Architecture Board

The Internet Architecture Board, or IAB, is on top of the heirachy. They review the Internet standards, oversee the other groups, and act to conserve control over Internet as an international network. Their probably most important role is to identify long term opportunities and how they should be handled.

IETF and IRTF

Almost directly under the IAB we have the Internet Engineering Task Force and the Internet Research Task Force. The IETF handles all the current protocol standards and promotes further development. IETF also handles operation and management of the Internet. The IRTF is more of the Internets future department. They take care of all the future problems of the Internet and how they are to be handled. Among their work is how the net should handles billions of hosts, faster connections and wireless Internet. For this they have to look at new protocols and how they can be incorporated into the current system without major service interruptions.

Request for Comments

On the Internet anyone can propose a standard. By writing a text that follows certain guidelines new features and standard can be proposed to the IETF User Services Working Group for review. If it is approved it will be assigned a unique number and it will be added to the Request for Comments (RFC) database. The first RFC was published in April 1969, then as a way to document the network. Today there are thousands of RFCs dating from the beginning of internetworking to present day, many have been outdated by newer ones along the way. The RFCs provide a great potential for the Internet to continue its development as new technologies can be presented quickly and then get standardised.

Internets Future

Next generation Internet

The current version of the Internet Protocol is version four. Abbreviated it is known as IPv4. When it was created the amount of computers connected to the Internet was not expected to be as high at it is. The addressing system, the IP addresses consist of four octets of numbers ranging from zero to 255 (example: 130.244.198.36). In technical terms this is 32-bits, a bit can be either null or one so this gives us almost 32^2 unique numbers. The actual number is a bit lower as all combinations are not allowed. This is quite a large amount of computers that can be connected but in fact estimates show that early in the next century the IP addresses will be exhausted. This is one of the reasons a new Internet Protocol version is being developed. Formally it is named Internet Protocol Version 6 (IPv6) but it is also known as IP Next Generation (IPng).

To provide more IP addresses the addresses in IPv6 have been expanded to 128-bit, or approximately 340,282,366,920,938,463,463,374,607,431,768,211,456 theoretically available IP addresses. This is the limit that the engineers think we will stay below for quite some time.

IPv6 has been designed to enable high-performance, scalable internetworks to remain viable well into the next century. A large part of this design process involved correcting the inadequacies if IPv4. One major problem that has been fixed is the routing. IPv6 does not use different network classes for routing instead it uses a system that provides flexibility to expand networks yet making the routing quick. With many addresses to work with the addressing has been layed out so they first of all are sorted by their major connection points. One such point is Sunet in Sweden, there all the major Swedish ISPs connect to each other as well as with foreign countries. Each ISP will then have a large address range that it can provide to companies, minor ISPs and dialup customers. This makes routing much easier, Internet backbone routers will no longer have to have huge databases of over 40,000 entries.

Security

With IPv4 there isnt any security at IP level. One of the design goals for version 6 is to provide authentication and encryption at a lower level. Previously encryption had to be done at a higher level, usually at the application layer. The authentication part makes sure that the information is actually coming from the source that it is claiming to be. This ensures that valuable data or passwords that is stored on a system cannot be spoofed (method to change the source address to make the packet appear coming from a different host) to intruders. Encryption is made by adding extra headers to the IP packet with encryption keys and other handshaking information. This way every packet can be encrypted by itself at a lower level, preventing sniffers (program to eavesdrop network traffic) from accessing the information in the packet.

Multicast and Quality of Service

As streaming audio and video becomes more widely used over the Internet along with other time critical applications like news and financial information the limitations of IPv4 become more obvious. Version 6 of the Internet Protocol has a feature called multicast. It allows broadcasters of audio and video streams to send out just one packet of the same information to many receiptants. It works like a tree, whenever a network is split into a few smaller ones, the information will be replicated and distributed down the tree. This decreases the network traffic as audio and video broadcasts are expected to increase heavily as more people get faster Internet connections. Quality of Service is also important for the future of streaming, by setting a high value of Quality of Service the routers in the path to the target computer will prioritise the packet thus leading to a faster delivery. The risk with is of course that all applications like e-mail and news that otherwise would be considered a non-time critical also set a high Quality of Service to make it get delivered quickly.

Neighbour Discovery

One of the major headaches for network administrators of large networks it managing IP addresses. The InterNIC wants to have as many addresses free as possible for future usage, giving the administrators a lot of work tracking which addresses that are used and which are free. When IPv6 is used on a network such problems can be disavowed. The protocol has a sort of autoconfiguration so when a host is connected to a network it will talk to the local router by using a temporary IP address and the router will tell the host what IP it should use. The router has previously been defined a range of addresses by the system administrator. In the same way if a network is moved or there is a change of ISP, resulting in a major IP change, the administrator will reconfigure the router to the new IP range and it will then, by the Neighbour Discovery (ND) protocol, tell the hosts their new IPs.

Forwarding

To support highly dynamic situations in the future IPv6, contains features for IP forwarding. When a user leaves work to go on a business trip for example he will logout from the local are network. The system will then tell the local router that all data to that user is to be forwarded to his laptop IP instead of his work IP. Forwarding allows domain name entries to be unchanged while the user is connected to a network on the other side of the earth.

Transition

When or if IPv6 makes it to the common market the transition will not be too hard. The next generation protocol is created to work with the old version of IP. The first routers that will be installed using the new protocol will also handle the old version so IPv4 can talk to it during the transition period. The only dependency that exists is the DNS. When a subnet is upgraded to IPv6, the domain name server must also be updated to handle the new IP addresses. The network that the subnet is connected to does not have to be upgraded. If an IPv6 host connects to a different IPv6 host on a different subnet where the data has to travel over an old IPv4 network, it will only get encapsulated with IPv4 headers. This method is called tunnelling. When the packet once reaches the destination IPv6 network the IPv4 headers will be removed by the router and the packet will be submitted to the correct IPv6 host. The old version four network will not know that it ever carried something it actually cannot handle.

6bone

Currently there is a virtual world-wide IPv6 network called 6bone created to test implementations of IPv6 in a working environment while not risking production routers and important systems. The network operates on top of the ordinary Internet by tunnelling discussed earlier. 6bone is not however a new Internet that we will move to once IPv6 is ready for commercial use, instead it is just a playground for scientist and it will disappear when IPv6 becomes widely used.

New domain names

Not in anyway related to the proposed IPv6 standard, seven new top-level domain names have been proposed as addition to the current com, org, net and others.

.firmfor businesses or firms

.storefor selling products

.webfor www related sites

.artsfor cultural sites

.recfor recreational and entertainment sites

.infofor information sites

.nomfor personal homepages

It might seem great with all these new categories but will they actually matter? The owners of many domains today registered them to make profit. By registering corporate or product names they want to sell them to the rightful owner later on. The same way they can also register good domains like video or cd.store by just being quick to register and then sell to the highest bidder. To stop domain opportunist large corporations also have to register their domain at all top level domains just the way they have done with the country domains. Most likely the new domains, whenever (or if) they arrive will just create a storm of registrations, and all the sought-after domains will be taken immediately. And along with them there will also be the normal copyright disputes etc that already exist with the .com domain.

Future connections

Many new connection forms are emerging as the demand for high speed Internet grows. Users no longer wish to browse with slow modems. In this section we will look into some of the technologies that might become popular in the future.

Fixed connections

The modems most people use to connect to the Internet have a speed of 33.6 kbps (thousand bits per second), this gives a transfer rate of about 3 kb/sec (thousand bytes per second) on the Internet. When downloading files this is very slow. The phone lines in general support much higher communication speeds, here are some of them.

Integrated Services Digital Network

ISDN is a speedier version of standard phone lines. The difference lies in the way the connection is handled. Instead of making calls analogue when sending them to the subscriber at the telephone station, digital technology is used all the way out over the standard copper cable. Normal phones are analogue, so this system requires an adapter that converts the signal to the analogue format. ISDN provides two channels of each 64 kbps for voice and data and one service channel at 16 kbps to handle communication between the telephones and telephone station, like notifying when there is an incoming call. Recent developments of ISDN allow the use of the service channel for other than service. Since this channel is used all the time, not only when a phone or the Internet is used, it would allow a computer connected with ISDN to be online constantly, and when needed it could connect with one of that data lines to provide higher speed. This addition to the ISDN system is not widely spread but it shows good use of existing technology.

Satellite

Connections through satellite is starting to become available, the pros of it is the high data transfer speed. Common users can expect speed ranging from 400 to 800 kbps while professional equipment could increase that speed dramatically over the 10 Mbps. The big con with satellites for consumer usage is that it is a one way system, you will have to have a modem connection open for communication back to the Internet (to request and acknowledge information). Another con is the latency, transferring data up to space takes a while, this creates some slight delays that could for example make gameplay over Internet very tedious.

xDSL

The DSL family of technologies is just like ISDN and extension of your current phone line. DSL technology however provides much higher speeds but also requires technical upgrades at the local telephone station. Besides that you cannot be to far from the telephone station as background noise will disturb the signal, giving you much slow transfers than the 9 Mbps that ADSL can offer. Digital Subscriber Line, which is its long name, is probably one of the connection forms that will be popular in the future, as long as you live near the telephone station.

Cable Modem

The cables that already are laid out to handle cable TV can carry data very well. Many cable networks are only good at providing data, users connecting through a cable modem can get speeds of a couple of Mbps from the Internet while sending might go down to a few hundred kbps. This differs widely depending on the system that the cable operator is using.

Mobile connections

GSM

Just as the Internet wasnt created to grow like it did, the European mobile phone system, GSM (Global System Mobile) wasnt created to handle data. The system is currently limited to 9.6 kbps, while normal telephone line modems can get speeds up to 56 kbps. This makes mobile Internet access very limited, only e-mail messages can be sent and received at a reasonable speed and browsing www would be very slow. Connection to a mobile phone is no longer needed, telecommunication companies have phones with integrated computers as well as PC-Cards with built-in phones. Fast communication over GSM is not very good yet but by the year 2001, the GSM systems are expected to be enhanced for data transfer at 384 kbps.

Universal Mobile Telephone System

On January 29 1998 in Paris at the European Telecommunications Standards Institute meeting the standard for the third generation of mobile phones was set. The first generation was analogue, the second generation had digital phone systems like GSM and AMPS (an American mobile phone standard). The new systems technical standard is called UTRA while the phone system is called UMTS. It has some major advantages over older systems. First of all the voice quality should be comparable to fixed lines, second and most important in this context is its support for higher data rates. For indoor access speeds up to 2 Mbps can be reached while wide area access only allows speeds up to 384 kbps. What really shows the aim for global mobile network communication is the support for multiple simultaneous connections and support for IP packet handling.

Wireless Internet

There are systems designed specifically for wireless Internet, in Seattle, Washington DC and San Francisco systems consist of 1000s of small transmitters on light poles. The system provides access all over the central area at ordinary modem speed. The system is very flexible in the sense you can move around freely in the city and it requires only a small antenna on the special Ricochetmodem. The system currently has more than 15,000 users and bandwidth upgrades to provide higher data speeds can be expected in the future.

Multichannel Multipoint Distribution System

A system similar to the above is MMDS, it does however require the receiver to have a small dish besides the modem making it non-mobile. The good part of it however is that it can do speeds up to 30 Mbps. Speeds like that allow television and video broadcasting. With digital transmitting technology it might also be possible to triple the speed. The problem with the system is that all the users in the same region share bandwidth, so when everyone wants to surf the web, it will not be as effective as when sending TV. This system is yet half-mobile since it does not require any cables to be drawn making it at least portable.

Shared Wireless Access Protocol

Not only are people expected to communicate with each other over the Internet, electronic devices at home will also be talking to each other in the future. Almost all the major computer companies are working together to develop SWAP, a protocol that defines how devices talk to each other by radio signals. The system would allow you to control telephones, lights, alarms, computers and ovens, all across the Internet. Technically one home network can control 127 devices and communicate at 2 Mbps. It was for these kind of applications the Internet programming languages Java first of all was created by Sun Microsystems. There are competing standards to both SWAP and Java however. Microsoft wants the devices to be control by a miniature version of their Windows operating system while electricity companies want the communication to go not by radio but through the electricity lines. They do have a good point with this as most of the devices that are planned to be connected to the home network are connected to with an electric cable. Also the speed of it is currently the same as SWAP, with improvements likely to come. Internet over electric lines also works for out of the house connections, like browsing and e-mail. The great advantage of it is that everyone has it and it would only require minor changes to the power system and a small adapter at home.

Conclusion

As Ive worked with this project Ive made up pictures in my head about he we will be connected in the future and how we will use the Internet. The only thing that I can say I am really certain will happen is mobile Internet. Cell phone usage and Internet usage has exploded hand in hand. The same way that we want to travel and make calls with our cell phones we will also want to travel and connect to the Internet. The problem with this is of course the bandwidth. Wireless communication doesnt at present day provide enough speed for useful usage. Perhaps UMTS will be the solution to this. As fixed Internet connections start to provide enough bandwidth to support real TV and video broadcasting the users will want the same features in their flexible laptop computers. The question is will the mobile Internet systems provide what the users want?

Connecting all our home devices into one local home network will be one of the great advantages of the Internet in the future. Letting all our home devices talk to each other has great advantages, just take for example a normal employee. Wouldnt it be great to have a camera in the fridge to check if anything needs to be bought on the way home from work? Or perhaps to start the coffee machine and have fresh coffee ready every morning at breakfast and when the work ends?

In the long run I think CD discs, DVD discs and other multimedia medias will be phased out. When users starting getting more bandwidth such devices will become redundant. The Internet is a better platform for multimedia than storage discs ever can be. Updates can be done in the information whenever needed making patches and updates unnecessary. An argument against this theory is that a DVD discs with its gigabytes of data will take a long time to transfer. In this lies the strength of the Internet, instead of sending all the data to the user in one large file it will be streamed. This way the user can use one part of the multimedia application while the next part is being downloaded to the computer, making it ready for use when the user wants it.

Mixing the local home device network (as I like to call it) with the Internet can have certain qualities. One scenario would be stereos, instead of playing radio from standard FM radio, the radio signals from all over the world would arrive over the electricity line. No more CDs, when you want listen to music, start your TV, go through the menu system until you find the song you want to listen to and it will be played over the Internet. Naturally the same goes for videos and games.

All of this of course has a price, the multinational corporations are racing to be first with a flexible working solution as the winner can expect large incomes. Users will in the future not buy a CD, perhaps they could buy unlimited listening to it but the standard would be to pay-per-usage.

I am quite determined that some time in the future we will have this scenario, what I am uncertain about however is if the personal computers will go away. We wont have to type on a keyboard, eventually we will get rid of it, but dont we want to have some kind of personal storage space that we know is ours, not publicly available to everyone over Internet. I dont really believe in Suns Network Computers, I am more for an intermediate solution of Networked Computers, they dont need CD-ROM or floppy drives, all they would need is a harddrive to store information and a network interface card for Internet access.

Working with this project has been very fun. Not only have I learned a lot, hopefully this small report about the Internet also can teach others. When I was finally finished writing, something struck me. All the information I used from the Internet I had printed on paper. Even if everyone will be connected in the future and all our devices around us will communicate with each other people will still want to be able sit back, relax and enjoy a good book. A physical one, made in real paper and printed with black ink.

List of references

Paul Simoneau: Hand-On TCP/IPMcGraw-Hill 1997, ISBN 0-07-912640-5

Mike Bracken: The battle for the WebInternet Magazine September 97, page 43

Ahrvid Engholm: Allt kretsar kring processornMikrodatorn 5-98, page 39

Mike Bracken New domain namesInternet Magazine November 97, page 47

Gte Andersson Radiont kopplar ihop elprylarDagens Nyheter 8 April 1998, page 1 / DN.IT

Paul Lavin Internet UnpluggedInternet Magazine March 98, page 62

David Moss Fast net accessInternet Magazine February 97, page 104

Martin Appel Trdls i SeattleInternetworld 1-98, page 41

Kari Malmstrm Jakten p ett mobilt InternetKontakten 5-98, page 21

Charles L. Hedrick Introduction to the Internet ProtocolsThe State University of New Jersey 3 October 1988

H. Gilbert Introduction to TCP/IP2 February 1995

What is the 6bone?http://www.6bone.net/about_6bone.htm , 21 January 1997

Simple Internet Transition Mechanismshttp://playground.sun.com/pub/ipng/html/ipng-transition.htm

Robert M. Hinden IP Next Generation Overview14 May 1995

IPv6http://whatis.com/ipv6.htm

Bay Networks IPv6 Whitepaper1997

Robert Zakon Hobbes Internet Timeline v3.11997

Dave Kristula The History of the InternetMarch 1997

Wideband CDMA Introductionhttp://www.ericsson.se/wcdma/wcdma/sub_intr/introduction.htm , 24 October 1997

WCDMA in briefhttp://www.ericsson.se/wcdma/wcdma/sub_intr/wcdma_in_brief.htm , 24 October 1997

The compelling case for Wideband CDMA for next-generation mobile Internet and multimediahttp://www.imt-2000.com/wcdma/wcdma/sub_tech/brochures/cdma.htm , 18 March 1998

ETSI SMG#24 bis Paris, France 29 January 1998http://www.imt-2000.com/wcdma/importan.htm , 30 January 1998

Page 20 of 20