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Internet and LAN Technology

CHAPTER 5

Chapter 5: Internet and LAN Technology 2

5 Chapter Contents

Section A: Network Building Blocks Section B: Local Area Networks Section C: Internet Technology Section D: Internet Access


5 SECTION ASection A: Network Building Blocks

Network Advantages and Challenges Network Classifications Geographic Scope: PANs, NANs, LANs,

MANs, and WANs Organizational Structure: Client/Server and

Peer-to-Peer Physical Topology


5 SECTION ASection A: Network Building Blocks

Network Links Analog and Digital Signals Bandwidth Communications Protocols


5 Network Advantages and Challenges Sharing networked hardware can reduce costs Sharing networked hardware can provide access to

a wide range of services and specialized peripheral devices

Sharing networked software can reduce costs Sharing data on a network is easy Networks enable people to work together

regardless of time and place


5 Network Advantages and Challenges

Networks may be vulnerable to unauthorized access from many sources and locations– More vulnerable than standalone computers

Wireless networks can be tapped from a “snooping” computer

Networked computers are susceptible to an increasing number of worms, Trojan horses, and blended threats


5 Network Classifications


5 Geographical Scope: PANs, NANs, LANs, MANs, and WANs

Personal Area Network (PAN) – interconnection of personal digital devices

Neighborhood Area Network (NAN) – connectivity spread over several buildings

Local Area Network (LAN) – usually connects computers in a single building

Metropolitan Area Network (MAN) – public high-speed network with range of about 50 miles

Wide Area Network (WAN) – consists of several smaller networks


5 Organizational Structure: Client/Server and Peer-to-Peer


5 Physical Topology

Arrangement of devices in a network Each connection point on a network is

referred to as a node A bridge can connect two similar networks A gateway joins two dissimilar networks

– Router


5 Physical Topology


5 Physical Topology


5 Network Links

Wired network– Twisted-pair cable– Coaxial cable– Fiber-optic cable

Wireless network– RF signals– Microwaves– Infrared light


5 Analog and Digital Signals


5 Bandwidth

The transmission capacity of a communications channel– High-bandwidth channel (broadband)

• Cable TV• DSL

– Low-bandwidth channel (narrowband)• Telephone system


5 Communications Protocols Rules for efficiently transmitting data from

one network node to another– Dividing messages into

packets– Affixing addresses to

packets– Initiating transmission– Regulating the flow of data– Checking for transmission errors– Acknowledging receipt of transmitted data


5 Communications Protocols

A packet is a “parcel” of data that is sent across a computer network– Circuit-switching technology vs. packet switching

technology• Voice over IP (VoIP)


5 SECTION BSection B: Local Area Networks

LAN Standards Ethernet Wi-Fi HomePNA and HomePLC Networks Installing a LAN Using a LAN


5 LAN Standards

LAN Technologies are standardized by the IEEE– ARCnet– Token Ring technology– FDDI– Ethernet– Wi-Fi


5 Ethernet

Simultaneously broadcasts data packets to all network devices– IEEE 802.3– CSMA/CD protocol


5 Ethernet

On an Ethernet, data travels on a “first come, first served” basis. If two workstations attempt to send data at the same time, a collision occurs.That data must be resent.

CLICK TO START


5 Ethernet

Varies in speed from 10 Mbps to 10 Gbps An Ethernet card is designed to support the

Ethernet protocols Ethernet hubs link workstations via cables

– Uplink port


5 Wi-Fi

Wireless networking technologies that are compatible with Ethernet


5 Wi-Fi

WEP (Wired Equivalent Privacy) encrypts data traveling over wireless networks

Equipment required for a wireless network– Wi-Fi card– Wireless access point

Bluetooth is a short-range wireless network technology


5 HomePNA and HomePLC Networks

HomePNA networks utilize existing telephone wiring to connect network devices– Special NICs and cables are required

HomePLC networks transmit data over power lines as low-frequency radio waves


5 Installing a LAN

CLICK TO START


5 Using a LAN

In this drive mappingexample, a server’s driveC is mapped as drive Fby a workstation.After the mapping is complete,the server’s hard disk appears in the workstation’s directory asdrive F and can be used just as though it were a drive connected directly to the workstation.

CLICK TO START


5 Using a LAN You can allow other

network users to view and edit files in the folders you’ve designated as shared


5 Using a LAN

The Network Connection tool helps you troubleshoot connection problems


5 SECTION CSection C: Internet Technology

Background Internet Structure ISP Infrastructure Internet Protocols IP Addresses Domain Names


5 Background The Advanced

Research Projects Agency designed ARPANET

The Internet has an estimated 200 million nodes and 500 million users today


5 Internet Structure


5 Internet Structure

Ping is used to find out whether a site is up and running

The Traceroute utility records a packet’s path


5 ISP Infrastructure


5 Internet Protocols

TCP and IP serve as the primary protocols responsible for message transmission on the Internet


5 IP Addresses

IP addresses are addresses that identify computers on the Internet– Static IP address– Dynamic IP address


5 Domain Names Easy-to-remember names for Internet servers

– Ends with an extension that indicates its top-level domain

Every domain name corresponds to a unique IP address– Domain Name System

ICANN coordinates technical management of the Internet’s Domain Name System


5 Domain Names


5 Domain NamesThe 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 notavailable, consider using a different top-level domain, such as biz instead of com.After you’ve found an available domain name you like, you can continue the registration process by filling out a simple online form.

CLICK TO START


5 SECTION DSection D: Internet Access

Dial-up Connections Cable Internet Service DSL, ISDN, and Dedicated Lines Wireless Internet Services LAN Internet Access Mobile Internet Access Internet Connection Roundup


5 Dial-up Connections

Uses POTS to transport data between your computer and your ISP

A modem converts digital signals from your computer into analog signals that can travel over telephone lines, and vice versa– Modulation / Demodulation


5 Dial-up Connections Modems are still

required, despite digital telephone technology

Modem speed is measured as baud rate

Many Internet connection methods provide faster downstream transmission rates than upstream rates


5 Cable Internet Service


5 Cable Internet Service

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

Always-on connection Neighborhood network


5 DSL, ISDN, and Dedicated Lines

DSL is a high-speed, digital, always-on Internet access technology that runs over standard telephone lines– DSLAM– Most DSL installations require service

technicians• DSL modem


5 DSL, ISDN, and Dedicated Lines

ISDN connections are slower than DSL and cable Internet service, but faster than dial-up– ISDN terminal adapter connects a computer to a

telephone wall jack and converts signals to travel over ISDN connection

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


5 Wireless Internet Service

Direct satellite service (DSS)


5 Wireless Internet Service

Fixed wireless Internet service broadcasts RF signals in order to offer Internet access to large areas– WiMAX– Wireless service providers are usually local or

regional businesses


5 LAN Internet Access

Cost-effective way to share one Internet connection among several computers

To establish LAN Internet access, you need:– An operational wired or wireless LAN– A router or a hub with router capabilities– A high-speed Internet connection, such as DSL,

ISDN, or cable Internet– A modem that corresponds to your Internet

connection type


5 Mobile Internet Access

A Wi-Fi hotspot is a wireless broadband Internet service offered in a public location– WISP

WAP is a communications protocol that provides Internet access from handheld devices



Handheld device services include:– Short message service (SMS)– Multimedia messaging (MMS)– Music fingerprinting– Games– City guides– E-mail– News, sports, stocks, and weather



Cellular service options


5 Internet Connection Roundup

CHAPTER 5 COMPLETE

Internet and LAN Technology