What is the Internet?

Surfing with the Sea Monster

Module NG03c

Why "Surfing with the Sea Monster?"

Audience and Objectives

It all started with Defense...

Birth of the Internet

Who "Runs" the Internet?

Types of Networks

Parts of the Internet

Packets: the Heart of TCP/IP

What can you do with Internet?

Getting Online

Review

Why "Surfing with the Sea Monster?"

Exploring the Internet - and enjoying its features - is known as surfing
The Internet is so vast, it is like an Ocean
...and exploring it can be an adventure because...

IT'S SO MONSTROUS!

Clicking on the colored bar here and throughout the document will return you to the Contents:

It all started with Defense...

Late 1960s: many incompatible nets
DARPA (sometimes known as ARPA): (Defense)Advanced Research Projects Agency
Problem: What if a bomb fell on a network nerve center?
Finding a solution: contracts with top university computer researchers

Birth of the Internet

For a detailed history of the Internet, see Hobbes 'Internet Timeline: http://info.isoc.org/guest/zakon/Internet/History/HIT.html

Computer Scientists had to develop software to run the distributed network.Some of the more vocal early developers included:

Dr. Vinton Cerf(RAND Corporation and MCI/Worldcom)
Dr. David Farber (University of Pennsylvania)
...and many others

Complex standards for working together: TCP/IP

TCP: Transmission Control Protocol
IP: Internet Protocol

DARPA made the TCP/IP standards public(!)
The network built using TCP/IP was originally called ARPAnet.

The Network Spreads

ARPAnet first linked 4 universities (late 1969)
By 1981, there were over 200 universities and other host computers on the net
Since then the number of computers connected has doubled approximately months

Figure 5

For details on growth of Internet hosts, visit the Internet Software Consortium site, http://www.isc.org/ds/

How do people use the Internet?

U.S. BROADBAND CONNECTIONS REACH CRITICAL MASS, CROSSING 50 PERCENT MARK FOR WEB SURFERS, ACCORDING TO NIELSEN//NETRATINGS
Young Adults and Kids Boast Highest Broadband Penetration; Seniors Still Log-on via Narrowband NEW YORK — August 18, 2004 — Nielsen//NetRatings, the global standard for Internet audience measurement and analysis, reported that broadband connections for the first time reached 51 percent of the American online population at-home during the month of July, as compared to 38 percent last July... Sixty-three million Web users connected to the Internet via broadband during July 2004 as compared to 61.3 million accessing the Internet through narrowband. Overall growth for broadband connections rose 47 percent year-over-year, while narrowband dropped 13 percent annually. “Despite a plateau in the growth of U.S. Internet access, we’ve seen continued high double-digit growth in users’ broadband access,” said Marc Ryan, senior director and analyst, Nielsen//NetRatings. “We expect to see this aggressive growth rate continue through next year when the majority of Internet users will be accessing the Internet via a broadband connection.” From Nielsen/NetRatings

U.S. BROADBAND CONNECTIONS REACH CRITICAL MASS, CROSSING 50 PERCENT MARK FOR WEB SURFERS, ACCORDING TO NIELSEN//NETRATINGS

Young Adults and Kids Boast Highest Broadband Penetration; Seniors Still Log-on via Narrowband

NEW YORK — August 18, 2004 — Nielsen//NetRatings, the global standard for Internet audience measurement and analysis, reported that broadband connections for the first time reached 51 percent of the American online population at-home during the month of July, as compared to 38 percent last July...

Sixty-three million Web users connected to the Internet via broadband during July 2004 as compared to 61.3 million accessing the Internet through narrowband. Overall growth for broadband connections rose 47 percent year-over-year, while narrowband dropped 13 percent annually.

“Despite a plateau in the growth of U.S. Internet access, we’ve seen continued high double-digit growth in users’ broadband access,” said Marc Ryan, senior director and analyst, Nielsen//NetRatings. “We expect to see this aggressive growth rate continue through next year when the majority of Internet users will be accessing the Internet via a broadband connection.”

From Nielsen/NetRatings

Who "Runs" the Internet?

Originally research-oriented scientists
The military were added in 1983, but they never "ran" the public portion of the Internet - they have their own private "internet"
In 1987 the network was reorganized: no longer run by DARPA but by the National Science Foundation (NSF). The name for the core network changed from ARPAnet to NSFnet. NSF assigned responsibility for day-to-day operation to a private consortium consisting of:

IBM, supplying hardware
MCI, supplying transmission lines
Merit (closely associated with the University of Michigan, Ann Arbor), operating the network

In 1995, the network in the United States was further privatized. By the nit was know widely as the Internet. It is now run by many participants .Various aspects of the Internet's management are handled by different groups:

Transmission is handled by many private companies, many of which are phone companies like AT&T, MCI,and Sprint
Domain name policies are guided by "the Generic Top Level Domain Memorandum of Understanding (gTLD-MoU, http://www.gtld-mou.org/),the international framework in which policies for the administration and enhancement of the Internet's generic Domain Name System (DNS) are developed and deployed." Because of the tremendous financial and political pressures surrounding domain names, the United States Department of Commerce's National Telecommunication and Information Administration (NTIA, http://www.ntia.doc.gov)was given a mandate to revamp the system in 1997. An agreement was reached late in 1999, giving many companies around the world authority to register domain names. These are accredited by the Internet Corporation for Assigned Names and Numbers (ICANN, http://www.icann.org).
Acceptance of new standards as technical development continues is handled by a number of committees, and ultimately by the Internet Society(http://info.isoc.org/isoc/),which provides an explanation.
Cooperation between the many national Internet organizations takes place at the Internet Society (http://www.isoc.org/)

Types of Networks

Definition -

Network: a group of computers connected together to exchange information.

The Problem:

Figure 1

Types of Networks:

The Star

This is the most common way of connecting electronic devices - local telephone service, local area networks, and many more. What is its security risk?

Figure 2

Types of Networks:

The Ring

In a ring network, computers pass messages around the circle until the message arrives at the intended destination. This is used in some local area networks. Would its design improve security and reliability over the star? Enough for national defense?

Figure 3

Types of Networks:

Distributed

In a distributed network, computers pass messages to one another using the fastest of several available paths. Does this have security advantages?

Figure 4 This is the network configuration that was chosen for the Internet.

Parts of the Internet

Internet is a network of networks of networks of networks...

Local area networks at companies and schools
Regional networks (such as Merit, linking most educational institutions in Michigan)
Commercial networks, regional and national
National "backbones" (like the early ARPAnet and later NSFnet)
International connections (mainly commercial)

(Illustration courtesy of Merit, Inc.'s 1995 report on the NSFNet Project)

Packets: the Heart of TCP/IP

To participate in the Internet, networks need to use TCP/IP. What's that?

A series of public standards documents

All messages on the Internet are transmitted using "packets" - standard information units...

Packet Switching 1

Messages are divided into packets
Each packet like an envelope...

To...
From...
Packet number...
Message

Figure 6

Distributed Packet Switching

Each computer on the net passes packets along the best route that leads toward the destination.

The best route is determined by continual monitoring of each line.

When a packet is sent to another computer, the receiving computer checks its accuracy.

If the packet was received inaccurately, the sending computer is asked to re-transmit
If the packet was received correctly, the receiving computer acknowledges receipt

If no acknowledgement is received after a given interval, the sending computer re-transmits the packet using a different route.
Response time from each computer is measured, and routes are compared to see which responds fastest.

Figure 7

When they reach their destination...

...packets may be out of order, but are re-assembled in the right order.

Figure 8

How effective is TCP/IP?

VERY! It is...

Flexible: It can be used for many purposes
Reliable: If parts of the network go down, computers automatically re-route packets around the trouble
Extensible: new networks can easily be added to existing ones

Getting Online

"Wholesale" vs. "Retail" connections

Larger organizations connect directly from LAN through dedicated phone lines
"People" use modems to connect to Internet Service Providers (ISPs)who usually have a bank of modems and a Unix or other powerful computer,which is connected to a regional or commercial network through direct connections.

Types of Internet Service Providers

If you don't have Internet access as a student or employee of a college or business, getting connected to the Internet involves finding some type of connection provider. Of the connection providers available to individuals,there are several kinds:

Internet Connection Providers give "bare-bones" service: just a PPP or "shell" to the Internet, often with electronic mail. Some of these are commercial, but others are offered as a public service.
Internet Service Providers (ISPs) provide a variety of Internet-related services; in addition to the connections, they may offer storage space for files, World Wide Web site hosting; possibly technical advice and Website design.
Value-added Service Providers historically predate the popularity of the Internet, in many cases. National corporations like CompuServe,Prodigy, GEnie, and America Online, originally provided an alternative to the Internet: their own email, news services, databases, entertainment,shopping, and wide-area networks .These services are still provided to their members, together with access to the wider Internet community.

More information is available about connection options in Module NG10c,"Internet Connection Options"

Enjoy the Internet!

That's all for NG03c.

About this document

Module NG03c - What Is The Internet? Surfing with the Sea Monster

Review: NG03cr

Author:: Laurence J. Krieg
Institution:: Department of Computer Information Systems, Washtenaw Community College
History:: Original: 9 June 1995 as PowerPoint presentation; HTML version: 3 Feb 1996; ACAC objective details added 2 April 2000; Last Update: Wednesday, 03-Apr-2002 10:54:50 EST

What is the Internet?

Surfing with the Sea Monster

Module NG03c

Contents

Why "Surfing with the Sea Monster?"

IT'S SO MONSTROUS!

It all started with Defense...

Birth of the Internet

The Network Spreads

How do people use the Internet?

Who "Runs" the Internet?

Types of Networks

The Problem:

Types of Networks:

The Star

Types of Networks:

The Ring

Types of Networks:

Distributed

Parts of the Internet

Internet is a network of networks of networks of networks...

Packets: the Heart of TCP/IP

To participate in the Internet, networks need to use TCP/IP. What's that?

Packet Switching 1

Distributed Packet Switching

Each computer on the net passes packets along the best route that leads toward the destination.

When they reach their destination...

...packets may be out of order, but are re-assembled in the right order.

How effective is TCP/IP?

VERY! It is...

Getting Online

"Wholesale" vs. "Retail" connections

Types of Internet Service Providers

Enjoy the Internet!

That's all for NG03c.

About this document

Module NG03c - What Is The Internet? Surfing with the Sea Monster

Review: NG03cr

Objectives:

Sponsored in part by CoNDUIT