1. The Internet

2. Overview In this chapter, you will learn to
Explain how the Internet works
Connect to the Internet
Use Internet software tools
Instructor Tip
When gaining attention and establishing common ground, ask questions to the class such as, “How many of you have Internet access at home?” or “What services do you use on the Internet?”
For a positive statement, tell the class, “In this lesson, we are going to learn how the Internet works, various ways that you can connect to it, and what you can do while on the Internet.”

3. Historical/Conceptual
How the Internet Works
Internet

4. Internet Tiers Tier 1 (main tier) Nine companies
Own long-distance, high-speed fiber optic networks called backbones
Interconnect at network access points (NAPs) in major cities

5. Internet Tiers Tier 2 Tier 3 Built-in redundancy
Smaller regional networks
Larger ISPs that provide Internet access are often Tier 2 providers
Tier 3
Even more regional networks
Built-in redundancy
Decentralized
Can easily adapt to failures on network

6. TCP/IP: Language of the Internet
TCP/IP is the common language of the Internet
Suite of protocols
Hypertext Transport Protocol (HTTP)
Most common protocol that provides structure for the World Wide Web
An Internet browser uses HTTP
Internet Explorer
Mozilla Firefox

7. Internet Service Providers
Internet service providers (ISPs) gain access to Internet through backbone
Leased from Tier 1 and Tier2 providers
Users gain access to the Internet thru ISPs

8. Connection Concepts Connecting to an ISP requires
Hardware for connectivity
Modem and working phone line
DSL or cable modem
Software (protocols)
Governs the connection and data flow

9. Getting the Right Sound Card
Essentials
CompTIA A+ Essentials
Getting the Right Sound Card
Connecting to the Internet

10. Ways of Connecting Dial-up Dedicated Wireless Satellite Analog ISDN
DSL
Cable
LAN
Wireless
Satellite

11. Dial-up Requires a Modem
The term modem is an abbreviation for modulator/demodulator
Enables computers to communicate with each other via standard telephone lines
Converts analog signals into digital signals
Converts digital signals into analog signals

12. Modems A modem uses serial communication
Transmits data as a series of individual 1s and 0s
Universal asynchronous receiver/transmitter (UART)
Converts serial into 8-bit parallel data

13. UARTS on Modems

14. Baud Rate
Baud rate is the basic cycle of time that a modem uses as its carrier frequency
Maximum baud rate of a phone line is 2400 baud
The modem speed is measured in bits per second (bps)
Modems can pack multiple bits into a single baud
14 bits × 2400 baud = speed of 33.6 Kbps

15. Communication Standards
Modern modem standards are referred to as V standards
Set by the International Telecommunication Union—Telecommunications Standardization Sector (ITU-T)
Both standards offer download speeds of just under 56 Kbps
V.90 upload speeds of up 33.6 Kbps
V.92 upload speeds of up to 48 Kbps
Rarely get throughput greater than 48 Kbps

16. Flow Control (Handshaking)
PCs handle local flow control using hardware or software
Hardware flow control uses extra wires called ready to send (RTS) and clear to send (CTS)
Called RTS/CTS
When in doubt, use hardware flow control
Software flow control uses special characters to signal the beginning and end of data transmission
Called XON/XOFF
Slower than hardware flow control and rarely used today

17. Modem Connections Modems connect to the PC in one of two ways
Internal modems connect to a PCI or PCI Express expansion slot
External modems connect through a serial port or USB port
Exercise
Installing a modem
Assign the students to install a modem and its drivers. After they install the modem, ensure that it is working using the Device Manager.

18. Dial-up Networking Dial-up networking Uses information from your ISP
The dial-up phone number, username, password, and other special configuration parameters
Configured in Network and Internet Connections applet
Select Set up or change your Internet connection and use the wizard

19. Dial-up Networking
Completing the setup of a dial-up Internet connection

20. Dial-up Networking Uses PPP protocol
Point-to-Point protocol (PPP)
Streaming protocol developed especially for dial-up Internet access
Most dial-up errors are user errors
Turn the volume up and verify the connection
Listen for a dial tone
Listen for “modem talk” instead of a person answering the phone

21. ISDN Integrated Services Digital Network (ISDN)
Phone companies have upgraded their network infrastructures to all digital lines (except for the line from your phone to the central office)
ISDN uses channels
B (Bearer) used for data and voice at 64 Kbps
D (Delta) used for setup and configuration information at 16 Kbps
Basic Rate Interface (BRI)
Most common setup
Two B (total of 128 Kbps) and one D channel
Discussion Points
ISDN service consists of two types of channels: “Bearer” or “B” channels and “Delta” or “D” channels. B channels carry data and voice information at 64 Kbps. D channels carry setup and configuration information, and carry data at 16 Kbps. Most providers of ISDN allow the user to choose either one or two B channels. The more common setup is two B/one D, usually called a Basic Rate Interface (BRI) setup. A BRI setup uses only one physical line, but each B channel sends 64 K, doubling the throughput total to 128 K. ISDN also connects much faster than modems, eliminating that long, annoying noise you get with modems. The monthly cost per B channel is slightly more than a regular phone line, and there is usually a fairly steep initial cost for the installation and equipment. The big limitation is that you usually need to be within about 18,000 feet of a central office to use ISDN.
T1 line
Discuss the Primary Rate Interface (PRI), a type of ISDN. Ask the students why PRI ISDN lines are rarely used as dial-up connections.
Another type of ISDN, called PRI (Primary Rate Interface), is composed of twenty-three 64-Kbps B channels and one 64-Kbps D channel, giving it a total throughput of 1.5 Mbps. PRI ISDN lines are rarely used as dial-up connections—they are far more common on dedicated lines.

22. DSL Digital subscriber line (DSL)
Uses a regular phone line but special equipment at both ends
Much faster than dial-up:
Upload: 384 Kbps
Download: 2 Mbps or greater
Installation requires a NIC and DSL receiver (often called a DSL modem)
Must be within 18,0000 feet from the closest main phone service switching center
The two most common forms of DSL you’ll find are asynchronous (ADSL) and synchronous (SDSL). ADSL lines differ between slow upload speed (such as 128, 256, or 384 Kbps) and faster download speed (usually 2 Mbps). SDSL has the same upload and download speeds, but telecom companies charge a lot more for the privilege. DSL encompasses many such variations, so you’ll often see it referred to as xDSL.

23. Cable Cable Uses cable TV connections
Connect the RG-6 or RG-59 coaxial cable to a cable modem
Connect modem to a NIC in the PC with UTP cable
Very fast speeds—as fast as DSL or faster
Bandwidth is shared with other users, which can affect performance
The term modem has been warped and changed beyond recognition in modern networking. Both DSL and cable fully digital Internet connections use the term modem to describe the box that takes the incoming signals from the Internet and translates it into something the PC can understand.

24. Other Internet Connections
LANs
Most companies connect their network to the Internet through an ISP
Users connect through the LAN
Wireless
Wireless connections require access via wired network
If wired network has access, wireless devices can use this wired network via a WAP
Satellite
Uploads previously done through modem
Initial connections still must be made through a modem
One form of wireless communication does not require local wires. Wireless broadband relies on the ISP putting up a tower, and then any building within the line of sight (perhaps up to 10 miles) can get a high-speed connection.

25. Internet Connection Sharing
Internet connection sharing (ICS)
Allows one computer to share single Internet connection with multiple devices
Available since Windows 98 SE
Requires a LAN between the devices first
Tech Tip
Hardware solutions for connection sharing
Several manufacturers offer robust, easy-to-configure hardware solutions that enable multiple computers to connect to a single Internet connection. These boxes require little configuration and provide a level of firewall protection between the primary computer and the Internet. You’ll find these boxes more commonly used with DSL and cable connections rather than any sort of dial-up. Linksys makes a DSL/cable router, for example, that offers four 10/100 Ethernet ports for the LAN computers; plus you can configure it so that to the outside world the router is the PC. It therefore acts as a firewall, protecting your internal network from probing or malicious users from the outside.
ICF enables you to open up specific computers inside a LAN for specific tasks, such as running an FTP server.

26. Windows XP Firewall Built into Windows XP
Originally named Internet Connection Firewall (ICF)
Changed to Windows Firewall in SP2

27. Internet Software Tools

28. World Wide Web
The World Wide Web (WWW) provides a graphical face for the Internet
Web servers house Web sites
Web browsers access the files on Web servers
Web browsers are highly configurable
A proxy server enables multiple connections to the Internet to go through one protected PC
Similar to ICS, but more sophisticated
Tech Tip
Ping
The command-line tool Ping may be your best friend for diagnosing TCP/IP errors. Ping always works; you don’t need to log on to a server or even log on to a system. Simply type in a DNS name or an IP address. To run Ping, get to a command prompt (Start | Run | type CMD | click OK) and type ping followed by a DNS name or IP address, like this: c:\>ping Then press the ENTER key. If the Web server is up, you’ll get a reply to that effect. You can even ping yourself: just type ping ( is known as the loopback address). If you get the famous “Request timed out” message, the device you are trying to ping is not available. Be aware, however, that “Request timed out” messages are fairly common when you use Ping on the Internet.

29. World Wide Web Security and scripts
Active programs and scripts such as Java and Active Server Pages
Can be useful and powerful
Can be malicious
Internet Explorer has configurable options
Tools | Internet Options | Security tab lets you set security levels

30. HTTP vs. HTTPS HTTP provides no encryption
HTTP over Secure Sockets Layer (HTTPS)
Provides encryption
Use when submitting personal information such as credit card numbers, phone numbers, etc.
Verify HTTPS is being used two ways
Lock icon
HTTPS appears in address bar

31. E-mail Two most popular e-mail programs E-mail protocols
Microsoft Outlook Express
Mozilla Thunderbird
protocols
Post Office Protocol version 3 (POP3)
Used for receiving
Internet Message Access Protocol (IMAP)
Used for receiving mail, but with more features than POP3
Simple Mail Transfer Protocol (SMTP)
Used for sending

32.
Configuring
Can use name or IP

33. Newsgroups Use a newsreader program to access newsgroups
Outlook Express most common newsreader (free)
News servers run Network News Transfer Protocol (NNTP)

34. File Transfer Protocol
File Transfer Protocol (FTP)
Used to share files
Requires an FTP server on one end and an FTP client on the other
WS_FTP is a popular client
Internet Explorer and other Web browsers also support FTP
Public FTP servers allow anonymous login
User Name: Anonymous
Password: address
Exercise
Using Internet tools
This exercise should allow the students to explore as many of the Internet tools as possible, including the World Wide Web, , FTP, newsgroups, and Telnet. In the rare event that a student does not have an account, use this opportunity to help the student establish a free account, such as those offered by Yahoo!. For exploring other services, you may want to specify addresses for the students to view certain Web pages, to download a program from an anonymous FTP site, or to access newsgroups.
The A+ Certification exams test knowledge of a few networking tools, such as Telnet, but only enough to let you support a Network+ tech or network administrator. If you need to run Telnet, you will get the details from a network administrator. Implementation of Telnet falls well beyond A+.

35. Voice over IP Voice over IP (VoIP)
Enables voice calls over the network
Works with any type of high-speed connection
DSL, cable, satellite, etc.
VoIP is a collection of protocols
Not a single protocol
Vendors
Skype
Vonage
Voice over IP (VoIP) lets you use the Internet like a telephone. It’s the subject of much legislative and legal wrangling between the phone companies (which are losing business) and companies that provide the service.

36. Terminal Emulation
Allows access to other computers as if you were there
University of Cambridge’s VNC
Free and totally cross-platform
Can run and control Windows from a Macintosh system

37. Terminal Emulation Remote Desktop Remote Assistance
Microsoft’s implementation
Free and built into system
Remote Assistance
End user requests help
Helper can take control of desktop
If permission granted

38. Beyond A+ Online gaming Chat World of Warcraft (WOW)
Internet Relay Chat (IRC)

39. Beyond A+ File sharing Allows users to share files with other users
Users can access any shared files (such as MP3s) on any computer anywhere on the Internet
Napster and Kazaa are file sharing programs
Music industry trying to stop file sharing
BitTorrent protocol to counter music industry
Also used for Linux distributions
µTorrent is one program using BitTorrent protocol