Network building blocks
All networks, large or small, require specialized network hardware to make them work. For small networks, the hardware may consist of nothing more than a network interface card in each computer, a cable for each computer, and a network hub that all the computers plug into. Larger networks probably have additional components, such as switches, routers, and repeaters. Small or large, all networks are built from the following basic building blocks:
✦ Client computers: The computers that end users use to access the resources of the network. Client computers are typically located on users’ desks. They usually run a desktop version of Windows such as Windows XP Professional, along with application software such as Microsoft Office. Client computers are sometimes referred to as workstations.
✦ Server computers: Computers that provide shared resources, such as disk storage and printers, as well as network services, such as e-mail and Internet access. Server computers typically run a specialized network
operating system such as Windows 2000 Server, NetWare, or Linux, along with special software to provide network services. For example, a server may run Microsoft Exchange to provide e-mail services for the network, or it may run Apache Web Server so that the computer can serve Web pages.
✦ Network interface cards (NICs): A card installed in a computer that enables the computer to communicate over a network. Almost all NICs implement a networking standard called Ethernet. Many newer computers come with either Ethernet cards already installed or with Ethernet support built into the motherboard so a separate card is not required. Every client and every server computer must have a network interface card (or a built-in network port) in order to be a part of a network.
✦ Cable: Computers in a network are usually physically connected to each other using cable. Although several types of cable have been popular over the years, the most commonly used cable today is called twisted pair, also known by its official designation 10BaseT. Another type of cable commonly used is coaxial, also called 10Base2. For high-speed network connections, fiber-optic cable is used. In many cases, the cables run through the walls and converge on a central room called a wiring closet. But for smaller networks, the cables are often just strung along the floor.
✦ Hubs and switches: Network cable usually doesn’t connect computers directly to each other. Instead, each computer is connected by cable to a device known as a hub or a switch. The hub or switch, in turn, connects to the rest of the network. Each hub or switch contains a certain number of ports, typically 8 or 16. Thus, you can use an eight-port hub or switch to connect up to eight computers. Hubs and switches can be
connected to each other to build larger networks.
✦ Wireless networks: In many networks, cables and hubs are making way for wireless network connections, which enable computers to communicate via radio signals. In a wireless network, radio transmitters and
receivers take the place of cables. The main advantage of wireless networking is its flexibility. With a wireless network, you don’t have to run cables through walls or ceilings, and your client computers can be
located anywhere within range of the network broadcast. The main disadvantage of wireless networking is that it is inherently less secure than a cabled network.
✦ Network software: Although network hardware is essential, what really makes a network work is software. A whole bunch of software has to be set up just right in order to get a network working. Server computers typically use special network operating systems (also known as a NOS) in
order to function efficiently, and client computers need to have their network settings configured properly in order to access the network. One of the most important networking choices to make is which network
operating system you’ll use on the network’s servers. That’s because much of the task of building a new network and managing an existing one is setting up and maintaining the network operating system
on the servers.
All networks, large or small, require specialized network hardware to make them work. For small networks, the hardware may consist of nothing more than a network interface card in each computer, a cable for each computer, and a network hub that all the computers plug into. Larger networks probably have additional components, such as switches, routers, and repeaters. Small or large, all networks are built from the following basic building blocks:
✦ Client computers: The computers that end users use to access the resources of the network. Client computers are typically located on users’ desks. They usually run a desktop version of Windows such as Windows XP Professional, along with application software such as Microsoft Office. Client computers are sometimes referred to as workstations.
✦ Server computers: Computers that provide shared resources, such as disk storage and printers, as well as network services, such as e-mail and Internet access. Server computers typically run a specialized network
operating system such as Windows 2000 Server, NetWare, or Linux, along with special software to provide network services. For example, a server may run Microsoft Exchange to provide e-mail services for the network, or it may run Apache Web Server so that the computer can serve Web pages.
✦ Network interface cards (NICs): A card installed in a computer that enables the computer to communicate over a network. Almost all NICs implement a networking standard called Ethernet. Many newer computers come with either Ethernet cards already installed or with Ethernet support built into the motherboard so a separate card is not required. Every client and every server computer must have a network interface card (or a built-in network port) in order to be a part of a network.
✦ Cable: Computers in a network are usually physically connected to each other using cable. Although several types of cable have been popular over the years, the most commonly used cable today is called twisted pair, also known by its official designation 10BaseT. Another type of cable commonly used is coaxial, also called 10Base2. For high-speed network connections, fiber-optic cable is used. In many cases, the cables run through the walls and converge on a central room called a wiring closet. But for smaller networks, the cables are often just strung along the floor.
✦ Hubs and switches: Network cable usually doesn’t connect computers directly to each other. Instead, each computer is connected by cable to a device known as a hub or a switch. The hub or switch, in turn, connects to the rest of the network. Each hub or switch contains a certain number of ports, typically 8 or 16. Thus, you can use an eight-port hub or switch to connect up to eight computers. Hubs and switches can be
connected to each other to build larger networks.
✦ Wireless networks: In many networks, cables and hubs are making way for wireless network connections, which enable computers to communicate via radio signals. In a wireless network, radio transmitters and
receivers take the place of cables. The main advantage of wireless networking is its flexibility. With a wireless network, you don’t have to run cables through walls or ceilings, and your client computers can be
located anywhere within range of the network broadcast. The main disadvantage of wireless networking is that it is inherently less secure than a cabled network.
✦ Network software: Although network hardware is essential, what really makes a network work is software. A whole bunch of software has to be set up just right in order to get a network working. Server computers typically use special network operating systems (also known as a NOS) in
order to function efficiently, and client computers need to have their network settings configured properly in order to access the network. One of the most important networking choices to make is which network
operating system you’ll use on the network’s servers. That’s because much of the task of building a new network and managing an existing one is setting up and maintaining the network operating system
on the servers.
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