Technology Introduction

Index

The Basics Of Networking

You need an Network!

Share your...

  • Broadband connection
    You won't be tied to the only computer with high-speed access.

  • Files
    No more transferring files around the house on floppy disks; you can even share your large music files so they don't take up space on multiple computers.

  • Printer and other peripherals
    Now everyone can use the "nice" printer without any fuss.

Secure your computers

Secure your home network, so intruders can't access your private files. Keep a record of attempted intruders if you want to report them to your ISP.

Expand your Network

Using standard technologies, it will be easy to add new computers and devices to your network.

So get started and find out how easy it is:

How do computers talk to each other?

Ethernet is a standard protocol that allows any number of computers to communicate with one another. These machines need to be connected to one another through Ethernet cable, or "Category 5" wiring. Similar to a phone line, Ethernet cables can have from four to eight wires, as much as double the amount found in a phone line.

Ethernet Cable Ethernet cable is usually a bit thicker than a phone line, and the jack looks like an oversized phone plug. Even an inexpensive home network will run at very high speeds, usually 10 or 100 Mbps. That's 200-2,000 times faster than a 56K dial-up connection! You can even configure your network to perform at twice that speed ("full duplex") if you need to stream audio or video across the network. Internet Service Providers (ISPs) may run their networks at 1000 Mbps (a gigabit).

The Ethernet standard is what allows these machines to talk to one another. Each computer (or printer or other device) that is connected to this Ethernet cable is set up to have a unique address, or IP Address.

What's an IP Address?

IP (Internet Protocol), is a standard way for computers to communicate. Generally, each computer has its own unique number. When two computers communicate, they use IP addresses to find one another. An IP Address is a set of 4 numbers between 0 and 255, each separated by a period. For example: 192.168.123.254. Even if a computer has a "name" on the network (to make it easier for you to remember), it still uses an IP address to communicate with other machines.

Messages or requests from one computer to another are broadcast, and all of the machines that are connected via an Ethernet cable can "hear" the message. The machine that is the intended recipient of the message responds, and the two machines transmit data to one another.

What do I need to create a network?

NICs In order to connect a computer to an Ethernet cable, the computer must have an interface. In a desktop this is usually a Network Interface Card (NIC) or USB adapter. In a laptop, it is usually a PC card, a module that plugs into the laptop. The Ethernet jack may also be built into the laptop itself.

You can make a very simple network if you have an interface in each computer and an Ethernet cable.

How do I connect computers?

This describes the basic requirements for a wired network. We will cover wireless networking next.

Connecting only two computers

Cables If you want to connect two computers, all you need is a "crossover cable" (or "twisted pair") and an interface in each computer. A crossover cable is an Ethernet cable that has a pair of wires that cross somewhere between the ends (see illustration). Usually, the wires inside an Ethernet cable go "straight-through." When constructing a network, you usually want to use straight through Ethernet cables, except when you are connecting one computer directly to another.

You can plug each end of the cable into each computer, and you have a very simple network! You should follow your operating system's directions for proper configuration instructions. You can share files and a printer, and if you have Internet Connection Sharing set up, your Internet connection as well.

Internet Connection Sharing (ICS) allows one computer to establish a connection to the Internet, and another computer on the network can access the Internet through the first computer (however, this required TWO NIC / network cards in the first computer). Windows 98SE or later support ICS. You should consult your Windows documentation for information on how to configure ICS. If it is not built into your operating system, there are shareware software that will allow you to run ICS on your computer.

You should also run a firewall on the computer that manages the Internet connection. Firewall software monitors the traffic passing through and prevents unauthorized outsiders from accessing your files.

Connecting three or more computers

In order to physically connect three or more computers, you should not use crossover Ethernet cable. You must be able to plug the Ethernet cables into a device that will allow signals to be transmitted to one another. There are several devices that will allow you to do this: a hub, a switch, or a router.

A Hub

A hub is simply a device that repeats the signals it receives. It does not "know" which computers are connected to it, and it does not do any network processing based on the source or destination computer. Hubs are primarily used as inexpensive devices that allow you to add more computers to your network.

However, as you increase the number of computers, you also increase unnecessary network traffic. Using a hub to connect a network is not very secure, as any computer in a cluster can be configured to "listen" to messages being broadcast. It is preferable to connect your network with a switch instead of a hub, especially since switches have become very affordable.

A Switch

A switch is similar to a hub, except that it registers the IP addresses of the computers plugged into it. When it receives a message, it only sends it to the intended recipient. Switches cut down on unnecessary traffic broadcasts and allow you to have an affordable high-performance network.

 

Switches are used to connect computers on the same network; they do not provide Internet access. You can still share your Internet connection through one of the computers on your network, however, as your network grows, you will see performance degrade. When one computer has to manage the Internet connection, it slows down network performance. If the main computer crashes, all of the other computers will lose their Internet connection. (You may also be able to plug your switch into your broadband modem, but only if you get multiple IP addresses from your provider. This usually costs more.) For increased performance and functionality, you need a router.

A Smart Switch

A Smart Switch has capabilities that lie between unmanaged and managed switches. They have some or all of the following Manageability, typically provided using a Web Interface which allows Performance Monitoring (port activity), the ability to configure network trunks (bandwidth control), and supports Port Mirroring. Quality of Service (QoS) which prioritizes traffic to support delay sensitive applications such as Voice over Internet Protocol (VoIP) and Streaming Video. Enhanced Security which offers support for Virtual LANs (VLAN).


A Router

A router is similar to a switch, but it performs a number of useful networking functions:

  • It allows you to create a home network (like a switch), but a router actually separates networks allowing you to share your Internet access without being dependent on one computer's connection (unlike a switch).
  • You can plug a printer directly into some routers, allowing printer access to any computer on the network.
  • It provides built-in firewall capabilities that do not hinder network performance.
  • You can share your broadband connection without purchasing additional IP addresses. (Check to see if your provider allows this.)

Linksys WRT300N Wireless N RouterWireless Networking

You can also get a wireless router. It performs many of the same functions, but allows you to combine a regular network with a wireless network.  (Many Wireless Routers are also regular Wired Routers at the same time - you choose how you want to connect).

What is a Wireless Router?

A Wireless Router provides all of the features of a Broadband Router, but it also allows you to network computers wirelessly.

  • You can connect many computers through a conventional (wired) Ethernet connection.
  • You can also network several additional computers wirelessly.

Now that you have learned all about conventional networking, you may want to read the following:

Tags: network, nic card, wifi, wimax

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