Download presentation
1
Chapter 9 Network Basics
2
Network Definition A network is a set of technologies that is used to connect computers The network allows communication and collaboration between users Networking is a group of technologies working together. These technologies include: Media is the wiring that connects the computers Hardware needs to be installed to connect the media Software needs to be written to handle networks
3
The Uses of a Network Simultaneous access to data
Network server is a central computer with large storage device and other resources that all users can share Data files are shared File servers Shared files stored on a server Access can be limited Software can be shared Application servers Site licenses Network versions Network server Users can share data stored on central server
4
The Uses of a Network Shared peripheral device
Printers and Faxes are commonly shared Reduces the cost per user Devices can be connected to the network Print servers control network printing Teaching tip Figure 9A.4 on page 344 shows a print queue. It can be helpful to demonstrate your classroom queue.
5
The Uses of a Network Personal communication Email Conferencing
Instantaneous communication Conferencing Tele conferencing Videoconferencing Audio-conferencing Data-conferencing Voice over IP Phone communication over network wires
6
The Uses of a Network Easier data backup
Backup copies data to removable media Server data backed up in one step Insider information The text describes needing special software to back up data from user drives. However, the backup utility that comes with Windows 2000 and XP is capable of performing this chore.
7
Assignment No. 2 What are the Network Operating Systems (NOS). Describe their roles? Comparison of features of Linux and Windows operating systems Write advantages and drawbacks of Internet in our life. (at least 5 each) Due date: 05 February, 2009
8
Common Network Types Local Area Network (LAN) Wide Area Networks (WAN)
Contains printers, servers and computers Systems are close to each other Contained in one office or building Organizations often have several LANS Wide Area Networks (WAN) Two or more LANs connected Over a large geographic area Typically use public or leased lines Phone lines Satellite The Internet is a WAN Teaching tip Use a real world example to describe an organization with interconnected LANs.
9
Hybrid Network Types Metropolitan Area Network (MAN)
Large network that connects different organizations Shares regional resources A network provider sells time Typically covers an area of between 5 and 50 km diameter Campus Area Networks (CAN) A LAN in one large geographic area Resources related to the same organization Each department shares the LAN
10
LAN, MAN, WAN
11
Hybrid Network Types Home Area Network (HAN)
Small scale network Connects computers and entertainment appliances Found mainly in the home Personal Area Network (PAN) Very small scale network Range is less than 2 meters Cell phones, PDAs, MP3 players
12
How Networks Are Structured
Server based network Node is any network device Servers control what the node accesses Users gain access by logging in Server is the most important computer Client/Server network Nodes and servers share data roles Nodes are called clients Servers are used to control access Database software Access to data controlled by server
13
How Networks Are Structured
Peer to peer networks (P2P) All nodes are equal Nodes access resources on other nodes Each node controls its own resources Most modern OS allow P2P Network Distributing computing is a form of P2P Kazaa is a P2 Possible threats? Teaching tip Discuss how users managing their own security settings can be bad.
14
Network Topologies Topology Packets
Logical layout of wires and equipment Choice affects Network performance Network size Network collision detection Packets Pieces of data transmitted over a network Packets are created by sending node Data is reassembled by receiving node Packet header Sending and receiving address Packet payload Number and size of data Actual data
15
Network Topologies Bus topology Also called linear bus
One wire connects all nodes Terminator ends the wires Advantages Easy to setup Small amount of wire Disadvantages Slow Easy to crash Teaching tip Pages 352 and 353 have diagrams of each network topology
16
Network Topologies Star topology All nodes connect to a hub Advantages
Packets sent to hub Hub sends packet to destination Advantages Easy to setup One cable can not crash network Disadvantages One hub crashing downs entire network Uses lots of cable Most common topology
17
Network Topologies Ring topology Nodes connected in a circle
Tokens used to transmit data Nodes must wait for token to send Advantages Time to send data is known No data collisions Disadvantages Slow Lots of cable
18
Network Topologies Mesh topology All computers connected together
Internet is a mesh network Advantage Data will always be delivered Disadvantages Lots of cable Hard to setup
19
Network Media Links that connect nodes in a network
Choice can be made depending upon the following factors: Speed of transmission Size of network Security Can be broadly categorized as: Wire-Based Media Wireless Media
20
Wire Based Media Twisted-pair cabling Most common LAN cable
Called Cat5 or 100BaseT Four pairs of copper cable twisted May be shielded from interference Speeds range from 1 Mbps to 1,000 Mbps
21
Wire Based Media Coaxial cable Fiber-optic cable
Similar to cable TV wire One wire runs through cable Shielded from interference Speeds up to 10 Mbps Nearly obsolete Fiber-optic cable Data is transmitted with light pulses Glass strand instead of cable Immune to interference Very secure Speeds up to 100 Gbps
22
Wireless Media Data transmitted through the air LANs use radio waves
WANs use microwave signals Easy to setup Difficult to secure
23
Network Hardware Network interface cards Network linking devices
Network adapter Connects node to the media Unique Machine Access Code (MAC) Network linking devices Connect nodes in the network Cable runs from node to device Crossover cable connects two computers Insider Information The Xerox Corporation controls the assignment of Ethernet addresses to NIC manufacturers.
24
Network Hardware Hubs Switches Center of a star network
All nodes receive transmitted packets Slow and insecure Switches Replacement for hubs Only intended node receives transmission Fast and secure
25
Network Hardware Bridge Router Connects two or more LANs together
Packets sent to remote LAN cross Other packets do not cross Segments the network on MAC addresses Router Network is segmented by IP address Connect internal networks to the Internet Need configured before installation
26
Network Hardware Gateway Connects two dissimilar networks
Most gateways contained in other devices
27
Network Cabling Cabling specifications Bandwidth measures cable speed
Typically measured in Mbps Maximum cable length Connector describes the type of plug
28
Network Cabling Ethernet Very popular cabling technology
10 Base T, 10Base2, 10Base5 Maximum bandwidth 10 Mbps Maximum distances100 to 500 meters
29
Network Cabling Fast Ethernet Newer version of Ethernet
Bandwidth is 100 Mbps Uses Cat5 or greater cable Sometimes called 100Base T Requires a switch Teaching tip Point out that the speed of the cable is the number before the word Base.
30
Network Cabling Gigabit Ethernet High bandwidth version of Ethernet
1 to 10 Gbps Cat 5 or fiber optic cable Video applications
31
Network Cabling Token ring Uses shielded twisted pair cabling
Bandwidth between 10 and 25 Mbps Uses a multiple access unit (MAU) Popular in manufacturing and finance
32
Network Protocols Language of the network Rules of communication
Error resolution Defines collision and collision recovery Size of packet Naming rules for computers
33
Network Protocols TCP/IP
Transmission Control Protocol/Internet Protocol Most popular protocol Machines assigned a name of 4 numbers IP address is the White House’s web site Dynamic Host Configuration Protocol Simplifies assignment of IP addresses Required for Internet access Teaching tip Have students determine IP addresses for the computer. On 2000/XP enter ipconfig /all. Windows 98 and back enter winipcfg.
34
Network Protocols IPX/SPX
Internet Packet Exchange/Sequenced Packet Exchange Older protocol Associated with Novell Netware Replaced by TCP/IP
35
Network Protocols NetBEUI Network BIOS Extended User Interface
Used by Windows to name computers Transmission details handled by TCP/IP Discussion Point Have students tell you what BIOS stands for.
36
Network Protocols Token ring Popular in manufacturing and finance
Nodes communicate when they have the token
37
Modem Communications Plain Old Telephone System (POTS)
Standard phone line Also known as Public Switched Telephone Network (PSTN) Two-way voice communication Uses analog transmission techniques Data communication is slow Insider Information The actual name used by phone technicians is Public Switched Telephone Network (PSTN). Mention POTS to the wrong technician and you will get an earful!
38
Modem Communications Modems Modulator/Demodulator
Modulator converts digital to analog Speed measured in bits per second (bps) Current fastest speed is 56 Kbps Quality of phone lines dictates speed V.92 is the current modem standard Several modem types Internal External Voice Fax Insider information The Federal Communications Commission (FCC) limits modem speed over an analog line to 53Kbps. Teaching tip Determine what your local ISPs support. If your ISPs do not support V.92, suggest to your students to purchase a V.90 modem. They will likely save $10 on the purchase and see no performance difference.
39
Modem Communications Modem uses Connection to the Internet
File transfer Uploading Downloading Teaching tip Draw a diagram showing the Internet ‘above’ the client computer to illustrate where the names come from.
40
Digital Data Connections
Digital phone lines Local telephone companies are upgrading Service will faster and more reliable New phones will be needed Modems will need to be upgraded
41
Digital Data Connections
Broadband connection Any data connection faster than 56 Kbps Common in business Becoming popular in home installations
42
Digital Data Connections
ISDN lines Integrated Services Digital Network Basic rate uses three channels Two data channels each support 64 Kbps Error correction channel Primary rate uses 24 data channels
43
ISDN Connection
44
Digital Data Connections
T lines High-capacity voice/data lines Used to control phone and data Several variants T1 transmits at Mbps T3 transmits at Mbps Teaching tip More information on T lines can be found at ckp.made-it.com/t1234.html.
45
Digital Data Connections
DSL technologies Digital Subscriber Line Popular with home users Speeds range from 100 Kbps to 30 Mbps Asymmetrical DSL (ADSL) Upload speed slower than download speed Symmetrical DSL (SDSL) Requires a DSL modem Teaching tip The website provides unbiased information regarding DSL providers.
46
Digital Data Connections
Cable modem connections Popular with home and office users Speeds between 1 and 3 Mbps Requires a cable modem
47
Digital Data Connections
ATM Asynchronous Transfer Mode Efficient transfer of video and sound Requires a special NIC and hardware
48
Wireless Networks Benefits No cable to pull
Mobile devices access network resources Mobility and flexibility for office workers Discussion point Wireless networks have drawbacks. Direct your students to discover some of these drawbacks including security, speed and complexity.
49
Wireless Networks Wireless 802.11 Also called Wi-Fi IEEE standard
Institute of Electronic and Electrical Engineers Several versions 802.11b connects up to 11Mbps 802.11g connects up to 56Mbps Use the same type of devices
50
Wireless Networks Wireless Access Point Center of a wireless network
WAP combined cover a larger area Range is 50 to 150 meters Extension points can extend range
51
Wireless Networks Wireless Adapters Used by devices to connect
Includes signal strength software Teaching tip Spend a little time here describing a home solution to share a broadband connection using a wireless solution. Describe products, security concerns and WAP placement.
52
Project Abstract Submission (next week)
53
Chapter 9 End of Chapter
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.