Internet history and_growthPresentation Transcript
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, III 1996 President 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
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
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 and The number of computers Part of the Internet backbone
Who Controls the Internet?
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:
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 WWW Created 1989 Mosaic Created 1993 A Mathematical Theory of Communication 1948 Packet Switching Invented 1964 Silicon Chip 1958 First Vast Computer Network Envisioned 1962 ARPANET 1969 TCP/IP Created 1972 Internet Named and Goes TCP/IP 1984 Hypertext Invented 1965 Age of eCommerce Begins 1995
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 from 1940s 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 that To browser web pages, running in a graphical user interface context. Great efficiencies can be accomplished if we use The 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
IP – Internet Protocol
an IP address is a 32-bit number
NKU’s web server has the IP 184.108.40.206
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?
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
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
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
Computers that store web pages and allow client computers to access them
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 scramento
Requests information from
A computer in Savannah
Message sent by MODEM
To Internet POP
To another component of the Internet backbone via microwave
To receiving station in NY
By microwave to another station in Atlanta
By phone to Georgia State
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)
such as from NKU – access via LAN is usually much better than through an ISP because of the use of T1 or better connections
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 divided into units called packets Each packet is given a copy of the destination address and sent on its way Each packet finds its way independently across the network Upon receipt, the receiving computer assembles the packets in order before displaying the message to the user
Packet Switching Continued
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
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
There are not enough Class B addresses for all of the networks and many networks that currently exist are outgrowing their Class C addresses Class Network Addresses Machine Addresses Class A 127 16 million Class B 16,000 65,000 Class C 2 million 254
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 Hosts Oct. ‘90 - Apr. ‘98
Having Internet Connectivity
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 CMC RPG Infotech Essel Sify Reliance Bharti VSNL Data Infosys HCL 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
Broadband wireless access
ISP connection options
Typical business connection
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 Internet
Dial 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.
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 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.