Planning a NetworkIn the previous lessons, you learned about using the world's largest computer network, the Internet. You have studied the basic principles of networks, examined the World Wide Web, looked at other areas of the Internet, and discussed ways to make your network and computers connected to the Internet more secure and to ensure yourself the safest online experience possible. You are almost ready to pull everything together to create your own network. The last remaining step before that is to do some initial planning.

In this chapter, you will examine different types of networks and begin planning all of the steps necessary to create your own network.

In this chapter, you will answer these questions:

Can we share files, printers, even an Internet connection using a network?

What else can we do over a network? What kind of a network do I need? What hardware is necessary to create a network? Do I need special software?

What Kinds of Things Can I Share on a Network?As you've learned throughout the course, networks offer many things that make your life simpler and keep you more in touch with those around the world than ever before. Popular uses of networks include:

File sharing Sharing equipment, such as printers, fax machines, and

scanners Connecting to the Internet Playing games

Networks are as crucial to information sharing as streets are to transportation. Now that you understand the basics, you can examine some specific functions of a network. Understanding what you want from a network is essential when setting up a network.

Can we share files?You can use a network to share a variety of files with other people. You can share documents you create, sound files stored on your hard drive,

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WARNING:Even though it is possible to share programs over a network, it is important that you only share programs for which you have permission to do so. For example, if you purchase a copy of Microsoft Word, you are only allowed to use that program on a single computer. If you want to share it with other users, you must purchase a site license that enables multiple people to use the same copy.

pictures you create in a graphics program. You can also share certain programs so that you only need to keep one copy of the software on the server.

Before networks were available, people would copy files to floppy disks to share them. This is known as sneaker net and is still a common method of sharing files. However, transferring files over the network protects the data, eliminates the risk of copying information to a disk that is easily damaged, and reduces the likelihood of introducing a virus to the system.

If you connect to someone else on the same network, or to a computer on a different network, you can even share files by dragging and dropping the files between folders, as if you were moving them around on your own computer.

Can we share printers?In addition to sharing files and programs online, you can also share resources such as printers and scanners. Before networks, each computer had to be connected to its own printer. Now, you can connect a printer to the network and all the other computers on the network can print documents using that single printer.

In addition to printers, you can share other resources as well. It is common to share a scanner, backup equipment, fax machine, or hard drives.

Can we share an Internet connection?With the popularity and importance of the Internet, it is important that all computers on a network have Internet access. This is possible by setting up an Internet connection for the network, with all computers accessing the Internet through the local network.

There are two basic methods for connecting a network to the Internet: using a router or a modem. A router is a piece of equipment that connects networks and directs, or routes, information to computers on the network. The router offers a connection between the network and the Internet. Figure 5-1 shows a router.

FOR MORE ISP INFORMATION:Check these sites to compare ISPs:

The List: The Definitive ISP Buyer's Guide: http://www.thelist.com

Free ISP: http://www.isps.8m.com/freeisp.htm

All Free ISP: http://www.all-free-isp.com

Find an ISP: http://www.findanisp.com

The Directory - Internet Access Providers: http://www.thedirectory.org

Freedom List: http://www.freedomlist.com

Figure 5-1:Router

A modem is a piece of equipment that connects a computer to the Internet via a phone line. When used with a network, the network connects to the modem, and then the modem dials up the server at the Internet Service Provider (ISP) and makes the connection. Common ISPs include national companies such as MSN, AT&T, and Earthlink, as well as thousands of local companies.

A dial-up modem, once the only option for going online, is now considered outdated by most corporations. They are slow and many of the newer technologies, such as streaming video, do not work well over a modem. Figure 5-2 shows an internal modem.

Figure 5-2:Internal Modem

HANDS-ON EXERCISE:Complete the hands-on exercise, Examining Modems & Routers here.

Are there other things we can do over a network?Many of the same things you can do on the Internet you can do over a private network. For example, you can set up email between computers on the network and you can play games between computers on a network. Many colleges offer network access from dormitory rooms. You can sit in your room and connect to the library without needing to go to another location to do your research. Once you are part of the workforce, you will find networks make it possible for you to work from home or on the road by connecting to the office network. The possibilities are really only limited by your resources.

Getting a network setup and running requires some planning, then knowledge of hardware, software, cables, and more. In the rest of this chapter, you will examine putting the network together, and then you will put it all together and even connect the network to the Internet.

What Does It Take to Make a Network?Before you can install a network, you need to do some planning. There are many experts in the field who believe planning is the single most important part of the process. Even in a small office or home network, you should do considerable planning. You need to consider such factors as size, speed, location, and cost. You will need to determine a design and whether you will need a server for a client/server system or connect the computers as peers. In this section, you will examine all of those questions.

What kind of network do I need?The first thing you must do when designing a network is to determine exactly what kind of network you need. How many computers will you need to connect? If you have less than ten computers, can you use a peer-to-peer network or do you need a server to establish a client/server network? How do you plan to transfer the information between resources on the network? How will you lay out the network?

Network architectureWhen designing a network, you need to consider how the information will be transferred between computers over the network. This is known as the network architecture. In large part, the architecture will determine the structure of your network, which you will examine below.

Every different type of network architecture has a set of standards, or protocols, that define how the information moves around the network. You might encounter four basic network architectures:

Ethernet architecture: the most popular and least expensive network architecture.

Token-ring architecture: often found in larger organizations, this is rapidly becoming an outdated network architecture.

ARCNet architecture: one of the oldest architectures AppleTalk architecture: developed by Apple to control

information transferred between Apple computers.The most popular architecture today is Ethernet. Since it is the one most often used, you need to be familiar with ethernet and understand some of the basic concepts.

There are several different types of Ethernet and each one can send information across the network at different speeds. The most common Ethernet is 100BaseT, also known as Fast Ethernet. There is also Gigabit Ethernet, which can transfer information more than ten times faster than Fast Ethernet. An older standard, 10BaseT, is still common in small businesses and home networks. Ethernet networks are the imost inexpensive type of network architecture.

Network topologyAnother important consideration is the structure of the network you want to install. The structure, also known as the network topology, is how the network is laid out and is usually dependent on the network architecture. This includes how the computers and the resources are placed physically and it also includes how the information is transferred between those computers.

There are four main types of network structures:

Star Bus Bus Ring Hybrid

Star Bus networksThe most common type of network structure today is the star bus network. In a star bus topology, each computer connects to a central point on the network. Figure 5-3 shows a star bus network topology.

NOTE:To visualize a star bus network, imagine a wheel with the hub at the center, like a central connection device, and the spokes going out from the center, like the computers connecting to the central device.

Figure 5-3:Star Bus Network Topology

There are some advantages and disadvantages to each type of topology. The features of a star bus network include:

You can add computers to the central connector without shutting down the entire network.

Each computer and device connects to the central connecting device.

If there is a problem with one computer on the network, the other computers continue to function, although they would not be able to access anything on the problem computer.

The computers can be no more than 100 meters away from the central connector.

Each central connector can connect up to approximately 24 computers.

Star bus networks are a bit more expensive than other topologies since each computer must connect to a central connector and you usually need large amounts of cabling to make the network function properly.

Bus networksA bus network is one in which all the computers connect along a continuous cable, known as a backbone. A bus network is popular with home networking systems or other small networks that connect only two or three computers. Figure 5-4 shows a bus network topology.

Figure 5-4:Bus Network Topology

The features of a bus network include:

The simplest and cheapest network topology to create. A single cable connects all computers. Only one computer at a time can transfer information. The

information travels along the cable and the recipient gathers the information from the cable.

You must add a terminator to each end of the bus network. When the cable gets to the last computer, it connects to that computer, and then the cable is terminated. This prevents the data from bouncing back through the network and interfering with newly sent data.

There is no need for a central connector. It is not easy to add computers to a bus network. You must

break the network connection to add a computer. If one computer on the network causes problems, all

computers on the network are impacted by the malfunction. Usually uses coaxial cable.

Ring networksA ring network features a single length of cable running between computers, which are configured in a ring. Ring networks are less popular today than in the past. Figure 5-5 illustrates a ring network topology.

NOTE:You will examine types of cable in Chapter 6.

Figure 5-5:Ring Network Topology

Ring networks, once widely used, are less popular today because of some of the limitations of that topology. The information only travels in one direction, so when you send information to a specific computer, the information must travel through each computer first. The computer will check to see if the information is addressed to that computer. If not, it then sends it on down the line to the next computer, and so forth. This can make for slow transmission times. The features of a ring network topology include:

Computers are located close to each other. There is no central connector. There is no beginning or end to the network, eliminating

the need for terminators. Difficult to troubleshoot. Network failure anywhere on the ring affects the entire

ring. It is difficult to add new computers to a ring network. You

need to bring the cable to add the computer and everything will be offline until you get the new system installed and running.

Hybrid mesh networksThere are many variations on these basic topologies. Because you can combine different topologies in the same network, hybrid mesh networks have sprung up that combine at least two different types of topologies.

For example, you can connect multiple star networks using a single cable. This then creates a bus network with multiple star networks branching off from it. Figure 5-6 shows a typical hybrid mesh network.

Figure 5-6:Hybrid Mesh Network

The features of a hybrid network topology include:

Networks between offices in different locations are often hybrids. The company might use a star bus network in the office in Seattle, and a bus network in the office in Atlanta.

You can connect different types of networks via a modem. For example, if you have a bus network at home, you can connect via a modem to your school network that uses a star topology.

Setup is difficult in hybrid networks because the configuration can get tricky when trying to make different topologies interact.

Hybrid networks, by their definition, are large, making them more expensive that a smaller, local network.

There are multiple communication paths, which help if there is a failure in one cable.

Other considerationsWhen you are planning the network, you need to look at other factors before you decide on the specific type of network. For example, you should consider:

NOTE:See the Topology Comparison Handout for a summary of the different topologies.

Any existing equipment; if your home, school, or office already has a network and you want to upgrade it, or you have specific computers available, you need to understand what is possible with your existing equipment.

Network size; if you have only a couple of computers, a peer-to-peer network is a possibility, whereas if you are connecting more than ten computers, you will need to focus on a client/server network.

The amount of information you want to share; the type and amount of information you plan to share can impact the type of network you need. If you are transferring large files, such as music, video, or graphic files, you will need a network that lets you share large amounts of information at a faster speed.

Physical location; where you plan to put the computers is important. If you have computers on different floors of a building, you will need to look at the best configuration for the computers and the best network topology for the space.

What hardware do I need?Once you have examined your needs and know the type of network you want to install, you are ready to consider the type of hardware you need. Hardware is the physical equipment that makes up your network, such as the computers, monitors, printers, and connection devices.

Network serversIf you have decided to use a peer-to-peer network, you will not need a server. A server is a vital component, however, of the client/server network. A server is a powerful computer that fills a specific function on the network. You might have a dedicated server to store files, to hold web pages, to handle email, and to backup your files. Figure 5-7 shows a typical network server.

Figure 5-7:Network Server

When you choose a server, you need to consider the following:

Expandability; the ability to grow as your needs change and expand.

Speed; the performance of a server is directly tied to the amount of memory and the speed of the chips, or Central Processing Units (CPUs).

Memory; servers require more memory than a regular computer. You can add memory as your needs grow; however, it is generally a good idea to add as much memory as possible within the budget to start. The more memory the server has, the more efficient the server will run.

Storage devices; most servers run large programs and handle massive amounts of data, so you should include enough storage capacity.

Storage; network servers are generally very large machines and they need to be in an area where they do not get too hot, where they aren't prone to accidental damage, and where there is not too much humidity.

Storage devicesA large network usually will include a file server to store information. The file server requires large enough and reliable enough storage devices to hold the information securely.

HANDS-ON EXERCISE:Complete the Server Specifications worksheet.

Storage devices can include:

Hard disk drives; these are the primary storage device found on a file server and in most other computers

Tape drives CD-ROM and DVD-ROM drives Optical drives Network storage

Network printersNetworks offer the advantage of sharing printers. Rather than needing one printer for each computer, multiple computers can share a printer. The type of printer on the network depends on the size of the network. For a home system, an ink jet or small laser printer is probably sufficient. On larger networks, there may be multiple laser printers and there is usually a print server. The print server is a computer that manages and stores all the print jobs sent to the printer from all the computers on the network. The print server receives print jobs, prioritizes them, and then sends the output to the correct printer.

Network Interface Cards (NICs)A network interface card (NIC) is installed inside each computer and connects the computer to the network cable. The NIC, as shown in figure 5-8, controls the information passing between the individual computer and the network.

Figure 5-8:Network Interface Card

Each NIC card that is made is given a unique number, known as an address. That address is then used to identify each computer on the network.

Connection DevicesWhen you learned about network topologies, you might have noticed that most of the topologies use network connection devices. These are various pieces of equipment that connect the computers on the network to each other or connect the network to other networks and other equipment. There are many different types of connection devices, each one serving a different purpose. Below are a few of the most common connection devices.

CHOOSING A PRINTER:When you select a printer for the network, you need to consider several items, such as printer speed, the print quality you need, and how many pages you will print in a give month. These are all items you can use to compare printers and make the best choice for your uses.

HANDS-ON EXERCISE:Complete the storage device exercise.

HANDS-ON EXERCISE:Complete the Network Interface Card exercise.

HubsA hub is the central connecting device to which all cables on the network connect. Although traditionally used only with star networks, hubs are now used in most network configurations. Figure 5-9 shows a typical hub.

Figure 5-9:Hub

Hubs receive signals from one location then send them back on their way through to the rest of the network.

A hub contains a series of sockets, known as ports, where you plug in the cables from various computer devices. Each hub can connect a different amount of computers, usually 4, 8, 16, or 24. If you have a large network, you can connect hubs to extend the network. Connecting multiple hubs is known as daisy chaining.

SwitchesA switch is similar in many ways to a hub. Whereas a hub gets a signal from one computer, then sends it out to the network, a switch gets the information from the network and sends the information to a specific destination on the network. You can only use switches on Ethernet networks. Figure 5-10 shows a typical switch.

Figure 5-10:Switch

RoutersRouters are connection devices that get incoming data, open the individual pieces of data, examine the address to see the destination, and

determine the best route for information to take to reach the intended destination. Figure 5-11 shows a router.

Figure 5-11:Router

The router examines the network and can detect if part of the network is running slow, or if there is a problem in some area. If the router finds a problem, it redirects the information around the problem so the information arrives quickly.

GatewaysA gateway is a connection device that links two different types of networks. The gateway receives information, translates it so that the destination network can understand it, then sends the translation on to the destination.

A gateway, shown in figure 5-12, is normally hardware that connects to the network and transfers the information between networks. However, it can also be software that translates information sent using different protocols over the same network.

Figure 5-12:Gateway

ModemsModems allow the computers on the network to exchange information. Modem is actually short for Modulator-Demodulator. Modems use telephone lines to exchange information. It converts it from digital information on one end of the network to analog information that the

HANDS-ON EXERCISE:Complete the connection devices exercise.

telephone lines can understand, then translates it back to digital information for the other network.

Figure 5-13 shows a typical network configuration with the various hardware components.

Figure 5-13:Network Configuration

Do I need special software?A network operating system (NOS) is the software that controls, organizes, and manages all activities on the network. The type of software you need depends on whether you have a peer-to-peer network or a client/server network.

Peer-to-Peer Network Operating SystemsPeer-to-peer networks are small, connecting less than ten computers. Each computer stores its own information and then shares that information with other computers on the network. Even though it's a small network, there must still be software that organizes the network. There are several different types of peer-to-peer network operating systems.

Windows 95/98/Me/XPMicrosoft Windows was developed for use on a single computer, each version does have built in peer-to-peer networking capabilities. When you use the newest version of Windows, Windows XP, to create a network connection, an automated process walks you through creating the network.

Client/Server Network Operating SystemsLarger networks, with more than ten computers and a central server, are client/server networks. The operating systems for those networks are more powerful and more complex than peer-to-peer operating systems.

Client/Server operating systems control such things as multiple servers, resources, security, and handle administrative functions such as usernames and passwords to access the network.

HANDS-ON EXERCISE:Complete the Planning a Network exercise.

Windows Server 2003Microsoft's client/server network operating systems, such as Windows NT Server and Windows Server 2000, have been around for years. The newest version, Windows Server 2003, offers a complete set of tools to help you manage your network. The software includes built-in security; full support for sharing files and services; secure Internet connection; and makes it easy to manage, whether the network is large or small.

What You've Learned About Planning a NetworkIn this lesson, you began planning your own network. Before you can actually start putting everything together physically, you have to understand what it is you need to accomplish, the tasks you want the network to perform, and then to develop a plan for how you want to structure your network.

What's Next? In the next chapter, you will pull everything together you've learned and create your own network. You will connect computers, and then go online using the network.

Terms to KnowReview the following terms:

10BaseT

100BaseT

AppleTalk Architecture

Architecture

ARCNet architecture

Bus network

Central Processing Unit (CPU)

Daisy chaining

Ethernet architecture

Fast Ethernet

Gateway

Gigabit Ethernet

Hardware

Hub

Hybrid mesh network

Internet Service Provider (ISP)

Modem

Network Interface Card (NIC)

Network Operating System (NOS)

Port

Print server

Ring network

Router

Server

Sneaker net

Star bus network

Storage device

Switch

Terminator

Token-ring architecture

Topology

Suggested Web Sites Networking Basics: http://www.lantronix.com/learning/tutorials/etntba.html

HomeNetHelp: http://www.homenethelp.com/web/explain/about-hubs-and-switches.asp

Topology: http://fcit.usf.edu/network/chap5/chap5.htm

Wikipedia: Network Topology: http://en.wikipedia.org/wiki/Network_topology

Network Topologies: http://www.webopedia.com/quick_ref/topologies.asp

Designing a Network Topology: http://staff.rit.tafensw.edu.au/mfinemore/NW%20Theory%20HTML%20pages/network_topology.htm

1. Examine two of the Web sites listed above and answer the following questions about each one:

a. Which Web site did you examine?

b. What type of Web site is this? Are they trying to sell something? If so, what do they want to sell?

c. What did you find most useful on this web site? If they are selling something, do they also have information you can use?

d. Who publishes this site? Explain a little about the organization or company that owns the site. Is the information on this site reliable? Explain.

e. Did you learn anything about networking that would help you when thinking about the different types of networks and why you might prefer one design to another? Explain.

f. Did this site lead you to other sites? If so, give one site you found helpful that you discovered from this site.

g. What is your overall impression of the site?

Questions for Review1. What are some of the things you can do over a network?

2. Discuss the difference between a Star Bus, Ring, and Bus network for a small home network. What would be the advantages and disadvantages of each?

3. Describe the differences and similarities between a hub, switch, router, and a gateway.