Day 24
LANs
Local Area
Networks
In this lesson we will learn;
How LANs are used
The differences between peer-to-peer and Client/Server LANs
LAN topologies
Ethernet, Token Ring, and ARCnet protocols
The differences between twisted-pair, coaxial, and fiber-optic cables
Local Area Networks are used to exchange data between desktop computers, which are arranged in a group. Computers within these groups can share printers, Internet, processor, and storage resources. Most LANs are used in small offices, schools, and gaming environments.
The benefits of
using a LAN are:
v Ease of sending, receiving, and printing data from multiple PCs
v Ease of backing up data
v Security of data
v Ease of program installation on multiple machines
LANs came to be because it is more cost effective to share data and resources on multiple computers than to have dedicated resources on each computer. In this way, an office with 5 computers can share just one Internet connection, one printer, one scanner, and one CD-RW using a LAN. If the same computers were not on a LAN, each would have to have all of these resources added to each stand-alone system, multiplying the cost many times.
The first LAN used in many businesses was called “Terminal Emulation.”
Later LANs used Novell’s NetWare (1983), which could link up to 16 PCs into a network. These setups were very expensive, but allowed the PCs to share hardware resources.
Peer-to-peer
Networks
This type of network has the following characteristics:
Ø Data and resources are shared between the computers without using a server.
Ø Failure of one computer does not doom the network.
Ø Servers are not used.
Ø Data transfer is slower than on a client/server network.
Ø Easy to install
Ø Lack tracking capabilities
Ø Low security
Ø Users are responsible for backing up there own data.
Ø Peer-to-peer networks can coexists within a client/server network setup.
Ø Peer-to-peer networks are best for the home and small business environment.
Ø Supported within Linux, Mac, Windows 9X and NT Operating Systems.
Client/Server
Networks
This type of network has the following characteristics:
Operating Systems made for the Client/Server are:
MS Windows NT, Novell IntraNetWare, UNIX, and Linux.
Topologies describe how the computers on the network are linked together.
In this topology, a single cable connects all of the computers in a daisy-chain fashion. This type is easy and low cost to build, but it is harder to add new systems to the network. It is, however, expensive to repair are maintain this network.
In this topology, a hub, or a central connection point is used. All data passes through this hub. It is easy to install new systems and easy to find problems on the network.
In this topology, cables are connected to form a ring. The computers connect within this ring and data travels though each system. Each system acts as a repeater, passing the data along to the next PC. These are more expensive, but very easy install and can be harder to reconfigure or add new systems.
In order of computers to share data, they must first set up which protocol to use. You can think of a protocol as a language. Protocols determine the way computers on a network communicate.
Ethernet can about in 1975 from the Xerox Corp. It first operated at 3 MB per second. In 1980 this was increased to 10 MB per second and called Ethernet 2. This is still the standard for the Internet. Ethernet is now capable of 10 or 100 MB per second throughputs. The media access method consists of rules, which determine which stations can access the cabling and when that access can occur. The computers monitor the cable by using a carrier sense, which checks the cable to see when access is granted.
Terms:
Carrier sense
Multiple access
Collision detection
Collision avoidance
Cables used
|
Implementation |
Cable type |
Throughput |
Transmission |
Max Length |
Max Length with repeaters |
|
10Base5 |
Coaxial |
10 Mbps |
Digital |
500 meters |
2500 meters |
|
10Base2 |
Coaxial |
10 Mbps |
Digital |
185 meters |
925 meters |
|
10BaseT |
Twisted-pair |
10 Mbps |
Digital |
100 meters |
500 meters |
|
10base36 |
Coaxial |
10 Mbps |
Analog |
3600 meters |
18500 meters |
|
10BaseF |
Fiber-optic |
10 Mbps |
Digital |
2000 meters |
10000 meters |
|
100BaseX |
Twisted-pair |
100 Mbps |
Digital |
100 meters |
500 meters |
This network standard allowed for compatibility between different manufactures’ products.
Network Interface
Cards
LAN cabling
Twisted-pair cable
Coaxial cable
Fiber-Optic cable
Wireless Networking
Interconnectivity
Repeaters
Bridges
Routers
Brouters
Gateways
Installing network cards
Examining the classroom network
A plus testing
Homework - Mixing
up Windows!
Write all of the solutions on a separate paper with your name and hand it in to me before the end of the next session.
Problem 1:
You have built a new machine and partitioned the 80 Gig HDD into 9 drives! They are seven 10 Gig drives, one 9.5 Gig, and one .5 Gig drive. After installing Win98SE on C drive, you install your programs on the other, larger drives. A few days go by and you get the following error: “your temp folder can only hold 134 MB, you need 240 MB free to run this program.” After thinking about it, you decide to move your temp or TMP folder to one of your larger drives. But you do not know how to do this! So you go to http://www.regedit.com
Do a search at this site to find the solution!
Problem 2:
You have made a DREAM SYSTEM with Win98SE for a friend. It costs you $1,200 to build and your friend says that he will pay you as soon as the system is done. When you finish the system, you call your friend and tell him the great NEWS! But he acts surprised and states that he thought that it would take 3 months to finish the system! He then adds that he has no money and that he would need a loan from you to even pay for it in three months. Dishearten, you put the system up for sale to the highest bidder. It sales the next week, but you had already entered your other friend’s personal data into the registry. So that the system says “logoff Hugh Lee O’Connor” when the new user shut down the system. Feeling that you have sold him a used PC, he demands that you change the user name info ASAP! You drive to his home and discover that you need to edit the registry to do this. So you go to
Do a search at this site to find the solution!
Problem 3:
You have made a nice system for someone and you get a call the next day from this user asking you to Change the Logon Screen Background Color, Change the Logon Screen Wallpaper, and Automatically View Thumbnails of Bitmap Files! You say okay and so you go to
Do a search at this site to find the solution!
Problem 4:
You build a system for a nice lady, who seems to be very excided about her new system. You set the system in her office and turn it on. As the system boots up, she notices that the flash screen (boot-up screen) says Win98 SE. She looks at you and informs you that she wants MAC OS installed on her new Intel P-III 933 system ASAP! Scratching your head, you remember hearing Mr. Berry talking about changing the Windows 98 GUI to look and act just like Mac OS.
Look at my site’s “Computer pages” and do a web search for “Mac theme,” “winmac,” “Vanessa Zoe”, and “Emulators - Run Mac OS on Windows”
Also got to
Write out each step of the process. Do not forget to tell me how to add an icon shortcut to the floppy onto the desktop.
