Question: Upgrading a Stand-alone Computer to a Networked Computer Time Required: 30 minutes Objective: Upgrade a stand-alone computer to a networked computer. Required Tools and Equipment: Lab computer (as specified in the book's lab setup instructions), a NIC, a patch cable, and a hub or switch Description: In this project, you install a NIC and connect it to an interconnecting device with a cable. This project can be done in groups or as an instructor demonstration. It's intended only to familiarize you with the hardware components needed to make a standalone computer a networked computer.

1. Install the NIC, following the steps your instructor provides. This process might involve opening the computer case or simply plugging a USB NIC into a USB slot.

2. Turn on the computer. If necessary, insert a disk containing the NIC driver and follow the instructions for installing it.

3. Using the supplied cable, plug one end into the NIC and the other end into the interconnecting device, which should be a hub or a switch.

4. Examine the indicator lights on the NIC and the hub or switch. There might be one or two lights on each port of the device, depending on its features. There's at least one indicator on the NIC and on each port of the hub or switch that's usually referred to as a "link light." The link light glows when a data connection has been made between the NIC and the hub or switch. Your instructor can supply more details about the indicator lights available on your hub or switch. List the status of indicators on the NIC and the hub or switch port into which the NIC is plugged:

5. Shut down the computer and unplug and put away the cables. The previous list of components satisfies the hardware components needed to make a stand-alone computer a networked computer. The computer must also have the necessary software to interact with network hardware and communicate with other computers on the network. Network software transforms a stand-alone OS into a network OS. It's the software that allows a word-processing program to open a document on a server or knows how to request a Web page or send an e-mail. It's also the software that communicates between the OS and network hardware. Network software can be divided into the following categories:

• Network clients and servers-Network client software requests information that's stored on another network computer or device. Network server software allows a computer to share its resources by fielding resource requests generated by network clients. Network client software can be an integral part of well-known applications, such as Web browsers and e-mail programs. A Web browser, for example, sends a request for a Web page to a Web server. Network client software can also run in the background, usually installed as a networking service. In this case, it enables programs without built-in client software to access shared network resources on other computers. For example, Client for Microsoft Networks, which is installed automatically in Windows, allows a word-processing program to open a file that's shared on another Windows computer or print to a printer attached to another Windows computer. In this setup, the server software called File and Printer Sharing for Microsoft Networks receives the request from the client and provides access to the shared file or printer.

• Protocols-When clients and servers need to send information on the network, they must pass it to network protocols, which define the rules and formats a computer must use when sending information across the network. A network protocol can be likened to a human language. Just as two people who want to communicate must speak the same language, two computers that want to communicate must use the same protocol. An example of a network protocol is TCP/IP. Network protocols do all the behind-the-scenes tasks required to make networking work and handle most of the complexity in networking; they're discussed in depth in Chapter 5.

• NIC driver-After a network protocol has formatted a message correctly, it hands the data off to the NIC driver for transmission onto the network. NIC drivers receive data from protocols and then forward this data to the physical NIC, which transmits data onto the medium. The reverse is also true. When data arrives at the NIC from the medium, the NIC hands it off to the NIC driver, which then hands it off to network protocols. Every NIC card installed in a computer must have an associated device driver installed in the OS. The device driver software manages the details of communicating with the NIC hardware to send and receive data to and from network media.