chapter 6 the internet. internet technology chapter 6: the internet 2 background internet...

Chapter 6The Internet

Internet Technology

Chapter 6: The Internet

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Background

Internet Infrastructure

Internet Protocols, Addresses, and Domains

Connection Speed

Background


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The ARPANET (Advanced Research Projects Agency), created in 1969, connected computers at UCLA, Stanford Research Institute, University of Utah, and University of California at Santa Barbara

Today, the Internet connects computers all over the globe and supplies information to people of all ages and interests

With an estimated 500 million nodes and more than 1.5 billion users, the Internet is huge



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The Internet is not owned or operated by any single corporation or government

The Internet backbone is a network of high-capacity communications links that provides the main routes for data traffic across the Internet

Backbone links and routers are maintained by network service providers (NSPs)

NSP equipment and links are tied together by network access points (NAPs)

An Internet service provider (ISP) is a company that offers Internet access to individuals, businesses, and smaller ISPs



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The Internet backbone includes high-speed fiber-optics links connected at Network Access Points.

ISP Equipment



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To communicate with an ISP, your computer uses some type of communications device, such as a modem



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A computer can have a permanently assigned static IP address or a temporarily assigned dynamic IP address

IPv4 – is a 32 bit IP and offers 4 billion unique addresses written in 4 octets of decimal numbers. Example: 204.127.129.1

IPv6 – 128 bits and offers billions and billions of addresses written in 8 groups of 4 hexadecimal numbers. Example: 2011:0db8:0:0:1319:8a2e:0370:57ab



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Domain Name Hierarchy


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edu intorg netgovcom mil

Top-level Domains (TLDs) are the highest level of domain names on the internet. There are 7 generic TLDs. Beneath these are Second-level domains (SLD).There are country-code Top-level Domains (ccTLDs) that are on the same level as the gTLDs.

google irsclayton

google.com clayton.edu

comcast

Examples of ccTLDs:•northpointonline.tv•crystalclassicsltd.co.uk•dilaps.or.tz



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The first step in registeringa domain name is to find out whether the name is currently in use or reserved for futureuse. If a domain name is not available, consider using a different top-level domain, such as biz instead of com. After you’ve found an available domain name, you can continue the registrationprocess by filling out a simple online form.

Connection Speed


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Data travels over the Internet at an incredible speed

The elapsed time for data to make a round trip from point A to point B and back to point A is referred to as latency

PingTraceroute

Upstream vs. downstream speed

Connection Speed


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When upstream speeds differ from downstream speeds, you have an asymmetric Internet connection

When upstream and downstream speeds are the same, you have a symmetric Internet connection

Internet connection options

Fixed Internet access (wall-socket)Portable Internet access (satellite dishes)Mobile Internet access (cell phone)

Question


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One reason the Internet works is because TCP/IP offers a global addressing standard. Which one of the following is accurate in the context of Internet addresses?A. IPv6 addresses such as 204.127.129.1 are

dedicated to educational institutions.B. Top level domains like EarthLink or AOL are

adequate for most consumers.C. A domain name, such as Amazon.com

corresponds to a unique IP address.D. A dynamic IP address begins with www.

Fixed Internet Access


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Dial-up Connections

DSL, ISDN, and Dedicated Lines

Cable Internet Service

Satellite Internet Service

Fixed Wireless Service

Fixed Internet Connection Roundup

Dial-up Connections


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A dial-up connection is a fixed Internet connection that uses a voiceband modem and telephone lines to transport data between your computer and your ISP

Dial-up Connections


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A voiceband modem converts the signals from your computer into signals that can travel over telephone lines

Modem speed is measured in bits per second



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T1, T3, and T4 lines are leased from the telephone company and offer fast, high-capacity data transmission (1.544 Mbps)

ISDN (Integrated Services Digital Network) is a type of fixed Internet connection that moves data at speeds of 64 Kbps or 128 Kbps over ordinary telephone lines ISDN terminal adapter connects a computer to a telephone

wall jack and converts signals to travel over ISDN connection

The following list shows some of the common line designations: DS0 - 64 k ilobits per second ISDN - Two DS0 lines plus signaling (16 kilobytes per second), or 128 kilobits per second T1 - 1.544 megabits per second (24 DS0 lines) T3 - 43.232 megabits per second (28 T1s)



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DSL is a high-speed, digital, always-on Internet access technology that runs over standard phone linesSome DSL installations require

service techniciansDSL modem



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Cable Internet service distributes always-on, broadband Internet access over the same infrastructure that offers cable television service



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Cable modems convert your computer’s signal into one that can travel over the CATV network

Always-on connection

DOCSIS-compliant cable modems



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Satellite Internet service distributes always-on, high-speed asymmetric Internet access by broadcasting signals to and from a personal satellite dish

A satellite modem is a device that modulates data signals from a computer into a frequency band that can be carried to the satellite dish where it is converted to another frequency, amplified, and transmitted



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Fixed Wireless Service


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Fixed wireless Internet service broadcasts signals in order to offer Internet access to large areasWiMAX (Worldwide Interoperability for

Microwave Access)A WiMAX system transmits data

to and from WiMAX antennas mounted on towers

Under ideal conditions, WiMAX can transmit data at 70 Mbps

Fixed Internet Connection Roundup


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Question


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Although ISPs offer Internet access though dial-up, satellites, WiMAX, ISDN, and DSL, cable Internet is currently the preferred access method. Why?A. It is the least expensive.B. It is the fastest and most widely

available technology.C. It has the highest latency.D. It was the original Internet access

technology.

Portable and Mobile Internet Access


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Internet to Go

Wi-Fi Hotspots

Portable and Mobile WiMAX

Portable Satellite Service

Cellular Data Service

Internet To Go


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Portable Internet access can be defined as the ability to easily move your Internet service from one location to another

Mobile Internet access offers a continuous Internet connection as you are walking or riding in a bus, car, train, or plane

Wi-Fi Hotspots


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A Wi-Fi hotspot is an area in which the public can access a Wi-Fi network that offers Internet service

Wi-Fi does not typically provide acceptable mobile Internet access because you can only remain connected within range of the network’s hotspot

Portable and Mobile WiMAX


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WiMAX can be used as a portable technology because Internet access is available to subscribers anywhere within a tower’s coverage area

You use the same Internet service provider whether you are at home or on the road.

Mobile WiMAX – uses tower to tower transfer of signal, much as a cell phone.

Portable Satellite Service


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Cellular Data Services


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Using cellular phone technology to access the Internet offers mobility that is not yet possible with most of today’s wired or wireless computer network technologies

Cellular Data Services


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The fastest cellular technologies for Internet access are EDGE, EV-DO, and HSUPA

Most cellular service providers offer a data service plan for accessing the Internet

You can use a smart phone or cellular-ready PDA to access the Internet by subscribing to a data service plan offered by a mobile phone provider such as AT&T or Sprint

Cellular Network Technologies


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Question


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What is the difference between portable Internet access and mobile Internet access? A. With portable access you cannot work online while

moving very far. B. Mobile access is less expensive than portable access. C. Portable access requires cables, whereas mobile access

does not. D. Portable access requires a cell phone, whereas mobile

access requires a notebook computer.

Internet Services


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Real-Time Messaging

Voice over IP

Grid Computing

FTP

File sharing

Real-Time Messaging


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A networked-based, real-time messaging system allows people to exchange short messages while they are online Instant messaging (IM)Chat

Messaging and chat protocols include IRC (Internet Chat Relay) and MSNP ( Mobile Status Notification Protocol) and Jabber.

Voice over IP


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VoIP (Voice over Internet Protocol) or Voice over IP, is a technology in which a broadband Internet connection is used to place telephone calls instead of the regular phone system

To set up a standard VoIP system, you can use an inexpensive ATA, IP phone, wireless IP phone, or USB phone

Voice over IP


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Advantages

Low costFlexibilityPhone number moves with

you

Disadvantages

Quality can varyMust have power to work

Grid Computing


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A grid computing system is a network of computers harnessed together to perform processing tasks

SETI@home project

Cloud computing depends on a grid of servers and storage devices that offer Internet-accessible computing services

Google apps Amazon’s Elastic Compute Cloud


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Cloud computing is the delivery of computing as a service rather than a product, whereby shared resources, software, and information are provided to computers and other devices as a metered service over a network (typically the Internet).[1]

FTP

FTP (File Transfer Protocol) clients such as FileZilla make it easy to upload and download files from an FTP server.


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FTP


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File Sharing

P2P file sharing uses peer-to-peer (P2P) protocols that allow users to obtain files from other users located anywhere on the Internet

BitTorrent is a file sharing protocol that distributes the role of file server across a collection of dispersed computers


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Question


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On the Internet, application protocols provide consumers with many useful services. Which one of the following correctly describes an Internet-based application protocol?A. Chat and Instant messaging use Internet

VoIP protocol.B. Files can be shared over the Internet using

FTP or BitTorrent protocols.C. Cloud protocols such as SETI control

distributed processing grids.D. P2P is used to encrypt personal information

to keep it private.

Internet Security


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Intrusion Attempts

Securing Ports

Routers and NAT

Virtual Private Networks

Intrusion Attempts


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An intrusion is any access to data or programs by hackers, criminals, or other unauthorized persons

Looking for open ports is one of the most common ways of gaining unauthorized access to a network-based computer

A port probe (or port scan) uses automated software to locate computers that have open ports and are vulnerable to unauthorized access

Intrusion Attempts


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Securing Ports

One of the easiest steps to enhance your computer’s security is to turn it off when you aren’t using it

A firewall is software or hardware designed to filter out suspicious packets attempting to enter or leave a computer


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Securing Ports


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Routers and NAT


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Routers are intended to work on LANs to monitor and direct packets being transported from one device to another

A routable IP address is one that can be accessed by packets on the Internet

A private IP address is a non-routable IP address that can be used within a LAN, but not for Internet data transport

Routers and NAT


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Routers and NAT


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Network address translation (NAT) is the process your router uses to keep track of packets and their corresponding private or public IP addresses



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It is possible to secure remote connections by setting up virtual private network (VPN) access to a remote access server in the corporate office

Access to a VPN is usually by invitation only. Employees who need to access a VPN are given the necessary instructions, addresses, and passwords to make connections



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A virtual private network (VPN) is a network that uses primarily public telecommunication infrastructure, such as the Internet, to provide remote offices or traveling users an access to a central organizational network.

VPNs typically require remote users of the network to be authenticated, and often secure data with encryption technologies to prevent disclosure of private information to unauthorized parties.

Question


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Securing your computer from Internet-based intrusions is an important aspect of computer security. Which one of the following is NOT a useful security technique?A. Setting up NAT on a routerB. Activating firewall softwareC. Checking the status of software portsD. Activating your computer’s file sharing

options

FastPoll True/False QuestionsAnswer A for True and B for False


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1. NAPs such as Earthlink and Comcast offer dial-up and cable Internet access.

2. TCP, IP, UDP, HTTP, and FTP are examples of protocols used on the Internet.

3. 204.127.129.100 is an example of an IP address.

4. .edu and .ca are examples of top-level domains.

5. Internet-based servers can handle multiple tasks using different ports.



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6. Utilities such as Ping and Traceroute help you gauge the speed of your Internet connection.

7. 10 Mbps is a narrowband Internet connection.

8. Dial-up, ISDN, and DSL provide Internet access using telephone cabling.

9. Cable Internet service is fast because it has lots of latency.

10. WiMAX uses low-earth orbiting satellites to transport data to the Internet.



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11. Portable Internet access includes Mobile WiMAX and Wi-Fi.

12. UTMS, EDGE, and HSUPA are examples of broadband ISPs.

13. VoIP uses circuit switching technology to send analog data.

14. SETI@home is a popular Wi-Fi service provider for non-business consumers.

15. Cloud computing uses distributed grid computing to predict weather.



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16. FTP makes it easy to anonymously use a search engine.

17. BitTorrent is an Internet security protocol.

18. Consumers should use port probes to encrypt data sent over the Internet.

19. NATs are used by hackers to intercept packets traveling over the Internet.

chapter 6 the internet. internet technology chapter 6: the internet 2 background internet...

Documents

internet slide

internet access

internet technology

internet backbone links

domains chapter

internet service provider

background chapter

hierarchy chapter