1. Wired Networks
CIT 1100
Chapter4

2. Wired Networks In this chapter you will learn- What a network does
Components of a wired network
To use a network to share resources

3. What is a Network?
Networks come in many sizes and vary widely in the number of computers attached
Connecting two computers in a home to share files and play games creates the smallest network you can have
Some companies have thousands of employees in dozens of countries and need to network their computers together to get work done.
Typically networks fall into one of two categories: LANs and WANs

4. Local Area Network
A Local Area Network (LAN) covers a small area and contains a modest number of computers
LANs are usually contained in a single building or group of nearby buildings
Typical LANs include home and school networks

5. Small Stand-alone local Area network
Wide Area Networks
A Wide Area Network (WAN) usually covers a large geographic area and can have a substantial number of computers, a WAN is typically composed of two or more LANs connected together
Small Stand-alone local Area network
Public
Network
Could grow into a multi-national Wide Area Network

6. Internet intranets
The largest WAN in existence is the Internet, which is a worldwide network that connects billions of computers and networks
An intranet, in contrast, is essentially a private network that is a scaled-down version of the Internet for a very specific group of users
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7. Servers and Clients
People use two types of computers in networks servers and clients
Servers share things such as files, folders, and printers
Clients enable you to access those shared things anything that makes requests is a client
A computer can act as a server or a client or both
Servers manage network resources making them available to the network

8. Network Classifications
Networks are traditionally classified into client-server and peer-to-peer, depending on the role played by each computer in the network
In a peer-to-peer network, computers on the network acts as both a client and a server

9. Networks
Networks offer many benefits over standalone computing in several categories:
Enhanced communication and collaboration
Easier sharing of files and resources
Increased personal productivity
Lower costs because of the sharing
Easier management of machines in the network

10. Networks
A network can make you lose control over your computer, add cost, and cause security problems
Users will not always have complete control over there computer settings and software
Additional costs for servers, cables, and network cards
Administrative costs
Problems can interrupt the entire network

11. Components
Connectivity between the PCs and a way to handle communication are handled in one of two ways:
Directly connected to a LAN via a cable from the computer to LAN port
Wirelessly to the LAN
Network clients have a network adapter or network interface card that connects to a central network box called a hub or switch

12. Network Interface Card
NIC provides the physical connection between the Computer and the Network

13. A Hub or a Switch provides a central connection point
Two PCs can be directly connected using a special cable called CROSS-Over cable to create a small Local Area Network
When 3 PCs or more need to be connected a different method is needed
A Hub or a Switch provides a central connection point
The Cross-Over cable is replaced with Straight-Through cables
Devices connected to a network that can be addressed separately are referred to as Nodes

14. Software
It takes both hardware and software to make network communication work
When computer A requests an file from computer B, the operating system and other software take file and break it into small, individu­ally numbered units called packets
The NIC takes the packets and, following the Ethernet standards, wraps up those packets into network frames that get sent out along the cable to the central network hub or switch

15. Ethernet Ethernet defines electrical signaling as well
The Ethernet standard defines everything about modern network hardware
Ethernet cables have standard connectors the most commonly used is the RJ-45 connector
Ethernet defines electrical signaling as well
That way the sending NIC will break data down into little pieces and the receiving NIC will know exactly how to put them back together

16. Ethernet
Most modern Ethernet networks employ one of three technologies:
lOBaseT  10 Mbps
lOOBaseT  100 Mbps
lOOOBaseT  1000 Mbs (1Gbps)
All have a distance limitation of 100 meters
100BaseT uses Category 5 (CAT 5) Ethernet cables Gigabit Ethernet runs on Category 6 (CAT 6) Ethernet cables

17. Duplex and Half-Duplex
New NICs run in full-duplex mode, meaning they send and receive data at the same time
The vast majority of NICs and Switches use a feature called auto-nego­tiating to allow very old devices that might attach to the network and need to run in half-duplex mode
Half-duplex means that the device can send and receive, but not at the same time,
Hubs are half-duplex devices

18. HomePlug
HomePlug (AKA Ethernet over Power) enables you to run a net­ work signal through the existing power outlets in your home
It is not a single product, but a set of industry standards
Plug your Ethernet cables into the HomePlug devices, plug the devices into an electrical outlet
This is not as fast as the fastest Ethernet (typically 85Mb/s) but it is simple to install

19. Hubs and Switches
Hubs and Switches sit at the very center of networking, handling the tasks of receiving and sending packets of data to the connected computers. Each functions quite differently when they receive an Ethernet frame
A hub simply repeats the frame down every network cable connected, hoping one of the computers connected is the recipient machine
A hub is not “intelligent” in that it makes no determination where it sends the data

20. Hubs and Switches
Unlike an unintelligent Hub a switch learns the network address of every machine connected to it, reads the recipient address on the frames, and sends them along only on the appropri­ate node
Switches are now much more common than hubs

21. That’s not addressed to me
HUBS
Send this frame to PC #3
All Hosts connected to the Hub receive the Frame since it is a shared connection
PC One Transmits a Frame Addressed to PC Three 3
One
That’s not addressed to me
Shared BUS
That’s addressed to me 3 3
When one Node on a hub is transmitting others must wait everything is Half-Duplex
Only Host 3 Receives it because it has 3s address
Three
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22. Switch Operation Laptop sends document to Printer File Transfer E-MAIL
A switch sets up concurrent connections, everything can be sent Full-Duplex
File Transfer
Server
Shared Printer
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23. Using Networks
Once you've assembled the pieces for a network, you can access files on a server, print to a shared printer, share files, etc…
Two things need to be in place before this all hap­pens
All communicating systems must be physically connected to the network
Devices, and folders must be shared to be accessible by the network

24. Using Networks
The physical connection has already been explained, the next requirement is to set up Permissions to determine what users are allowed to do:
Accessing the file
Deleting the file
Moving the file
Copying the file
And more

25. Share and Set Permissions
To share a file on a network –
Select Share this Folder
Start by locating the file-
Click on Advanced Sharing
Right Click and select the Folders Properties
Click on the Sharing Tab
Open Computer  Navigate to the folder
You could optionally assign a share name that would be displayed on the network or leave it “Pictures”
Note If you do not have administrative rights you will be prompted for the password
You can specify number of users that can simultaneously access the file

26. Share and Set Permissions
To Set permissions on a the network –
Click on Permissions
You can Allow or Deny-
Full Control – Users can see the contents of a file or folder, change existing files and folders, create new files and folders, and run programs in a folder
Change - Users can change existing files and folders, but cannot create new ones
Read - Users can see the contents of a folder and open files and folders