Internet History and Growth

What Is the Internet?• A network of networks, joining many

government, university and private computers together and providing an infrastructure for the use of E-mail, bulletin boards, file archives, hypertext documents, databases and other computational resources

• The vast collection of computer networks which form and act as a single huge network for transport of data and messages across distances which can be anywhere from the same office to anywhere in the world.

Written by William F. Slater, III1996President of the Chicago Chapter of the Internet Society

• The largest network of networks in the world.

• Uses TCP/IP protocols and packet switching .

• Runs on any communications substrate.

What is the Internet?

From Dr. Vinton Cerf, Co-Creator of TCP/IP

ARPANET• In 1968, the Defense Department began

developing ARPANET ARPA – Advanced Research Projects

Agency•WAN (wide area network) designed to

connect DoD researchers and university researchers

•Development of WANS, routers and the Internet Protocols

• used packet-switching

ARPANET– ARPANET went on line in 1969 connecting

4 computers in California and Utah•In 1972, Email was invented •In 1973, APRANET went international

with sites in England and Norway•The ARPRANET grew rapidly in the

1980s:–By 1981: 213 computers–By 1984: 1000 computers –By 1987: 10000 computers

From APRANET to INTERNET

• In 1982, the military portion of the ARPANET was separated into MILNET

• Supervision of ARPANET was passed to the NSF (the National Science Foundation)

• In 1983, the new TCP/IP protocol was added

From APRANET to INTERNET

• By 1990, the original ARPANET backbone was decommissioned in favor of newer long-distance data transmission networks– The collection of NSF-sponsored

backbones and the regional sites it connected together became the Internet

From Internet to WWW

• By the early 1990s, the Internet was primarily used to connect Universities together– Other commercial WANs began to connect

to the Internet•Genie, CompuServe, Prodigy, etc

– Popular applications were Email, FTP

From Internet to WWW

– In 1994, a graphical Internet browser was developed to allow easy access to materials stored on the Internet• the first web browser was called Mosaic

– This gave birth to the World Wide Web, the collection of interlinked files on the Internet• which has led to full-scale exploitation of the

Internet for global communications

Commercialization of the Internet

• Before 1995 commercial traffic was forbidden on the taxpayer-funded NSF

• In 1995 when NSF eliminated all Internet subsidies commercial Internet development took off.

The Internet Today

Areas of the world andThe number of computers

Part of the Internet backbone

Who Controls the Internet?• No one• The Internet is made up of privately

owned computers and networks, all of which agree to implement the Internet protocols.

Who Controls the Internet?• Some organizations control certain

aspects of the Internet – W3C, World Wide Web Consortium issues

standards related to all aspects of the Web.

• The Internet is everywhere and yet it is not in any one location.– In fact, the Internet was designed to

survive a nuclear war

Brief History of the Internet

• 1968 - DARPA (Defense Advanced Research Projects

Agency) contracts with BBN (Bolt, Beranek & Newman)

to create ARPAnet• 1970 - First five nodes:

– UCLA– Stanford– UC Santa Barbara– U of Utah, and

• 1974 - TCP specification by Vint Cerf• 1984 – On January 1, the Internet with its 1000

hosts converts en masse to using TCP/IP for its messaging

*** Internet History ***

A Brief Summary of the Evolution of the Internet

1945 1995

Memex Conceived

1945

WWWCreated

1989

MosaicCreated

1993

A Mathematical

Theory of Communication

1948

Packet Switching Invented

1964

SiliconChip1958

First Vast ComputerNetwork

Envisioned1962

ARPANET1969

TCP/IPCreated

1972

InternetNamed

and Goes

TCP/IP1984

HypertextInvented

1965

Age ofeCommerce

Begins1995

From Simple, But Significant Ideas Bigger Ones Grow

1940s to 1969

1945 1969

We can access information using

electronic computers

We do it reliably with “bits”, sending and receiving data

We can do it cheaply by using Digital circuits etched in silicon.

We can accomplish a lot by having a vast network of computers to use for

accessing information and exchanging ideas

We will prove that packet switching works over a WAN.

Packet switching can be used to send digitized data though

computer networks

Hypertext can be used to allow rapid access to text data

From Simple, But Significant Ideas Bigger Ones Grow

1970s to 1995

1970 1995

Ideas from1940s to 1969

We need a protocol for Efficient and Reliable transmission of

Packets over a WAN: TCP/IP

The ARPANET needs to convert to a standard protocol and be renamed to

The Internet

Computers connected via the Internet can be used more easily if hypertext links are enabled using HTML

and URLs: it’s called World Wide Web

The World Wide Web is easier to use if we have a browser thatTo browser web pages, running in a graphical user interface context.

Great efficiencies can be accomplished if we useThe Internet and the World Wide Web to conduct business.

The Creation of the Internet

• The creation of the Internet solved the following challenges:– Basically inventing digital networking as we know it– Survivability of an infrastructure to send / receive high-

speed electronic messages– Reliability of computer messaging

IPAddresses

IP – Internet Protocol

• an IP address is a 32-bit number• NKU’s web server has the IP 192.122.237.7

• routers throughout the Internet relay messages from one location to another using the IP address of the intended recipient

Internet Addresses and Aliases

• Its hard to remember these long numbers• We give our machines “aliases” instead

– NKU’s web server is known as sappho.nku.edu (or www.nku.edu)

• We use aliases for convenience, it is necessary to convert from an alias to an IP address when sending a datagram– Domain Name Servers (DNS) are tables

stored on various computers on the Internet that do this conversion for us

The World Wide Web

• Many refer to the Internet today as the Web, or the world wide web (www)– In fact, the WWW is an application that runs

on the Internet• It has a collection of files stored on certain

computers on the Internet known as web servers

– What makes it a web?• Links

The World Wide Web

– In a Web page, there are links to other files• Links are commands that tell a computer to go

out and retrieve another file over the Internet• But unlike older Internet technologies where the

user had to know the IP address, the link contains the address so there is nothing to memorize

• Click on a link your computer sends a message across the Internet requesting the specified document (web page) referenced in the link

– the receiving computer sends the page back and your computer loads it and displays it in your browser

URLs• A link includes the location of the document

being referenced– These links are called URLs

• Uniform Resource Locators

– URLs have four parts:• Protocol (http, ftp) : //

– the protocol determines what will be done with the document when it is received, http: display in a browser, ftp: save to disk

• Server - the web server storing the document you want• Path - the directory where the document is stored• Document (file) name

– Example: http://www.nku.edu/~foxr/CSC150/ch1.ppt

– NOTE: just because there is a link, doesn’t mean it has the right address – the address may be old, the file may be gone, this leads to broken links (or dead links)

Web Browsers and Web Servers

• Web servers – Computers that store web pages and allow client

computers to access them

• Web browsers – allow clients to access web server

• If you have web pages on your computer but no web server, no one can see those pages (outside of you)

• A web site is a collection of web documents available on a computer running the web server software– The home page (or index page) is the main page,

the first one retrieved

Accessing a Web Page

REGIONAL

LOCAL

1. You request a Web page.

2. Your request goes to your ISP’s point of presence (POP).

3. Your request goes to a network access point (NAP).

4. Your request goes to a national backbone network.

5. Your request reaches the Web site’s server and the Web page is sent back to you in packets.

YOU ARE HERE

NATIONAL

Internet Communications:

A Variety of Technologies

Computer in scramentoRequests information fromA computer in Savannah

1) Message packaged2) Message sent by MODEM3) To Internet POP4) To another component of

the Internet backbone via microwave

5) To satellite6) To receiving station in NY7) By microwave to another

station in Atlanta 8) By phone to Georgia State9) Where the message is

received by destination machine

Configuring Your Computer• What you need to get to the Internet:

– TCP/IP (which is available in the OSs)– Communications equipment to connect your

computer to a network:

• A physical connection to the Internet– Dialup access : modem– DSL, Cable or Satellite access

• Access the Internet through your signal provider using a special modem over the line to your house (coaxial, satellite dish or DSL line)

– LAN access • such as from NKU – access via LAN is usually much better

than through an ISP because of the use of T1 or better connections

• Network card

Interoperability• The Internet is made up of many different

– Types of computers (IBM PC, Mac, mainframes, Unix workstations, etc)

– OSs (windows, Mac OS, Unix, Linux, VMX)– LANs (Ethernets, Appletalk networks, etc)

• This makes the Internet a cross-platform network• All of these computers must be Interoperable

– they must speak the “same language” – in this case, the language is the TCP/IP protocol

• Transmission Control Protocol/Internet Protocol

– IP protocol dictates how addresses and routers work– TCP: reliable delivery, congestion control, service

requested

Internet: Packet Switching Network

Messages are dividedinto units calledpackets

Each packet is givena copy of the destination address and sent on its way

Each packet finds itsway independently across the network

Upon receipt, thereceiving computerassembles thepackets in orderbefore displayingthe message to the user

Packet Switching Continued

Intranets• Because of the success of TCP/IP, many networks

are being configured today to use TCP/IP– But rather than being a part of the Internet, they only

connect local computers together– Thus, the organization has the same abilities as Internet

users (email, ftp, messaging, etc) but communication remains local• A firewall might be placed between a company’s Intranet and

the Internet so that critical information can not be sent out and viruses and other harmful attacks can not make their way in

• The firewall is special software running on a computer that acts as the point of contact (or connection) to the Internet

– An Extranet is an Intranet that is open to certain pre-specified users, so in a way, its like opening up your network to only a portion of the Internet but where you dictate who gains access

Who Do You Trust?• The Web is a great source of information.

One problem is that there are no rules about what people can say on their web sites– Inaccurate information– Irrelevant information– Out-of-date information

• In examining information, keep in mind– who the author is– whose server it is– who the author’s source is– keep in mind accuracy and currency (date) of

data• the web is littered with web pages that haven’t been

updated in years!

The Future of the Internet• A billion Internet users by 2010?

– Can the IP protocol support this? No• There are about 4 billion unique IP addresses

available but there will not be enough to go around

• A newer version of IP addresses is being considered called IPv6 – 128 bit address

Class NetworkAddresses

MachineAddresses

Class A

127 16 million

Class B

16,000 65,000

Class C

2 million 254

There are not enough Class B addresses for all of the networks and many networks that currently exist are outgrowing their Class C addresses

Future of the Internet

– We will also have a problem supporting the need for super-fast connections to transfer large data files

• such as music and movies

• I2 (Internet 2)– a project for developing gigaPop – gigaPop: a gigiabit per second point of

presence– access to a backbone service capable of

transferring in excess of 1 Gbps.

Internet Growth Trends

Internet Growth Trends

• 1977: 111 hosts on Internet• 1981: 213 hosts• 1983: 562 hosts• 1984: 1,000 hosts• 1986: 5,000 hosts• 1987: 10,000 hosts• 1989: 100,000 hosts• 1992: 1,000,000 hosts• 2001: 150 – 175 million hosts• 2002: over 200 million hosts• By 2010, about 80% of the planet will be on the Internet

No. of Participating HostsOct. ‘90 - Apr. ‘98

Having Internet Having Internet ConnectivityConnectivity

• To have complete Internet connectivity you must be able to reach all destinations on the net.

• Your packets have to get delivered to every destination. This is easy (default routes).

• Packets from everywhere else have to “find you”. This is done by having your ISP(s) advertise routes for you.

ISPs having all-India license

BSNL CMCRPG InfotechEssel SifyReliance BhartiVSNL Data InfosysHCL Infinet Tata Power Broadband

Internet service provider (ISP or IAP)

ISP is a business or organization that provides consumers or businesses access to the Internet and related services. In the past, most ISPs were run by the phone companies. Now, ISPs can be started by just about any individual or group with sufficient money and expertise. In addition to Internet access via various technologies such as dial-up and DSL, they may provide a combination of services including Internet transit, domain name registration and hosting, web hosting.

ISP connection options

Typical home user connection • Dial-up • DSL • Broadband wireless access • Cable modem • ISDN

ISP connection options

Typical business connection • DSL • SHDSL • Ethernet technologies

DSL - Digital Subscriber Line

DSL is one of the most prevalent forms of Internet connection. DSL provides high-speed networking over ordinary phone lines using digital modems. DSL connection sharing can be easily achieved with either wired or wireless broadband routers.

Cable - Cable Modem Internet

Cable modem is a form of broadband Internet connection. Cable Internet uses neighborhood cable television conduits rather than telephone lines, but the same broadband routers that share DSL Internet connections also work with cable.

Dial Up InternetDial up uses ordinary telephone lines but, unlike DSL, dial up connections take over the wire, preventing simultaneous voice calls. Dial up routers are difficult to find, expensive, and generally do not perform well given such a slow Internet pipe. Dial up is most commonly utilized in lightly populated areas where cable and DSL Internet services are unavailable

ISDN - Integrated Services Digital Network

ISDN works over telephone lines and like DSL, supports simultaneous voice and data traffic. Additionally, ISDN provides 2 to 3 times the performance of most dial up connections. Home networking with ISDN works similarly to networking with dial up.

Satellite Internet

Enterprises like Starband, Direcway and Wildblue offer satellite Internet service. With an exterior-mounted mini-dish and a proprietary digital modem inside the home, Internet connections can be established over a satellite link similar to satellite television services.

POP(Point of presence)An Internet point of presence is an access point to the Internet. It is a physical location that houses servers, routers, ATM switches and digital/analog call aggregators. It may be either part of the facilities of a telecommunications provider that the Internet service provider (ISP) rents or a location separate from the telecommunications provider. ISPs typically have multiple POPs, sometimes numbering in the thousands. POPs are also located in Internet exchange points and collocation centres.

Internet POP DesignInternet POP Design

• Point of Presence (POP)– An access point to the Internet– A router is required to interface with

the service provider– Demarcation point is where the ISP

company ends and the private network of the customer begins.