First, let me define network. In a nutshell, a network is a combination of hardware, cables, and software that allows computers and printers to talk to each other. (Heck, you don’t even need cables with a wireless network, as I show you in topic 3 of this minibook.) To have a network, you need the right hardware and software — and did I mention that all the hardware and software that you need probably came with your Macbook? (Except for those pesky cables, of course.) As you progress through this topic, you’ll discover everything that’s required to set up your network so that you can pick up any additional parts you need. Any good-sized computer store (either the brick-and-mortar or online variety) has everything that you need to get up and running.
Now, back to the requirements: You need the right hardware and software to make your network sing. This section covers each component with a description about the role that each part plays on the network and other good stuff you’ll want to know to get your network right the first time.
Something to network
Okay, this might be obvious, but I’m nothing if not thorough. The first thing that you need to build a network is . . . well, stuff! That’s right, you need to have devices that you want to network. Most times, these are computers (whether Macs or PCs running Windows/Linux/UNIX), printers, personal digital assistants (PDAs), cell phones, and other standalone, network-capable devices (such as file servers and shared tape back-up drives).
Network interface card (NIC)
A network interface card, or NIC, is a hardware device that your computer uses to talk to the rest of the network. The NIC connects to the network cabling, and it speaks the language of electronics, sending data around the network. Nowadays, most networks use the Ethernet networking protocol, and most NICs are Ethernet compatible. All Macbooks have some type of Ethernet NIC hardware built right onto the Mac’s main system board. (Note, however, that the Macbook Air offers only wireless hardware built in; you can add a wired Ethernet port to the Macbook Air using an external USB connector.)
Switch
So you have an assortment of devices in your home or small office that you’ve decided to network. How do you make them all interconnect? Although you could connect just two computers by using nothing more than a single crossover cable, you need fancier hardware to connect more than two computers: namely, a switch. The switch is used to connect everything, so it’s the focal point of the network. Without a switch, you don’t have a network.
A switch is really just a small box that has a bunch of Ethernet ports on it. A port is really just like an Ethernet NIC on your computer, but a switch has lots of them. Inside, all those Ethernet ports are arranged so that the talking (sending) wires from each port connect to the listening (receiving) wires on all other ports. Therefore, when one computer talks, all others listen.
Thirty-nine flavors of Ethernet . . . but no Rocky Road
Wired Ethernet standards allow for operation at different speeds. Because the Ethernet standard has improved over time, some older Ethernet devices support only the older (slower) speeds. Ethernet’s speed is rated by how much data it can transfer in a second — usually in millions of bits per second, or megabits per second (Mbps). Originally, Ethernet was designed to run at 10 Mbps. Now there are different speeds of Ethernet: 10 Mbps, 100 Mbps, 1000 Mbps, and even faster.
The 1000 Mbps Ethernet — also called Gigabit Ethernet or just Gigabit for short — is still a bit on the expensive side for small home or office networks. All consumer-level Gigabit Ethernet NICs also support running at 10 Mbps or 100 Mbps, so you will hear them called 10/100/1000 Ethernet NICs. All current Macbook models come with a 10/100/1000 Ethernet NIC built in — except the Macbook Air, which has integrated wireless Ethernet hardware instead.
(Apple offers a USB-to-Ethernet converter for those Macbook Air owners that need a wired connection, but the connection is significantly slower.)
Although Gigabit NICs are now priced under $50, most of the devices that can connect Gigabit NICs still cost significantly more than their 10/100 counterparts. That fact, coupled with the reality that most computer systems can’t really even handle or dish out that much data, makes Gigabit Ethernet a choice only for those wanting a high-end network with the best performance.
NICs and other Ethernet equipment that handle only 10 Mbps are rapidly becoming obsolete because virtually all the modern NICs and other Ethernet hardware support both 10 Mbps and 100 Mbps. Most times, you’ll see this labeled as 10/100 Ethernet. For your home networking, you probably want to invest in 10/100 Mbps.
Setting up a switch (and therefore giving birth to your network, which sounds more painful than it is) is usually no more difficult than connecting a power cable to the device and then plugging in your computers with their own Ethernet cables. You’ll see various lights on the box — usually a power light indicating that the switch is powered on and operational. You’ll also see lights that correspond to each port on the switch; these lights tell you what’s going on in the box. For instance, you normally see the following types of lights:
♦ Link light: Each port on a switch should have a link light. Link lights simply tell you which ports have something alive connected to a given port — that is, a device is connected and powered on.
♦ Speed light: Each port on the switch should have a speed light, which tells you the speed of the device at the other end. Some switches have different lights for different speeds, and some use a single light and make it different colors for different speeds.
♦ Activity light: When one computer speaks, they all hear it. Typically, an entire switch has only one activity light for the entire network, indicating that someone is speaking. With heavy traffic, the light can appear solid.
Bear with me whilst I spew techno-talk for a paragraph or two. When an Ethernet switch receives a frame — that’s the name for a standard unit, or packet, of network data — it reads the label on the frame to see the return address of the computer that sent the frame. In a short amount of time (after being turned on and watching the data move around), a switch figures out which computer is located on which port. Then, whenever data comes into the switch, it looks at the header (some information on the front of all frames, much like a mailing label on a package that you send) and sees which computer should receive the frame. The switch then sends the frame out the port for that computer only.
This is A Good Thing. Instead of forcing all computers on the network to listen while your Macbook speaks (as antique network hubs did) — known as half-duplex — a switch sends the data directly to the only computer that needs to hear it.
Cables
Cables are the ties that bind . . . literally. Cables are used to connect the Ethernet port on each computer to the switch, the central hardware of the network. With a little experience, you’ll be a cable-wielding superhero with hundreds of feet of cable draped across every piece of furniture in your place for your first LAN party. (A LAN party, by the way, is when way too many techies bring their computers into a very small space, connect them, and play games for 48 hours straight. Oh, and we eat a lot, too. Good stuff!)
Here’s the scoop on what kind of cables to use. Technically, you can run 100 Mbps Ethernet over Cat5 cable (like a super-version of the wire that you use for your telephones).
Although you can do 10/100 Mbps Ethernet over Cat5 cable, any new cables that you buy should be Cat5E or Cat6 — which I talk about in the following section — because these types of cables are specifically meant for use with 1000 Mbps (or Gigabit) Ethernet. I’m sure you noticed that the common denominator here is the Cat5 cable. That’s because fiber optic cable, although supporting speeds of 100 Mbps, 1 Gbps, and even 10 Gbps, is much more expensive and more difficult to install.
Hey, did I mention that you can eschew cables entirely? For more information on the lean, mean world of wireless networking, see topic 3 of this minitopic.
Be sure to buy straight-through Cat5E/Cat6 cables (also called patch cables) and not crossover cables, which are used only in certain circumstances. Crossover cables are mainly used to connect two computers directly (to form a tiny, two-computer network), connect a cable/DSL modem directly to a computer, or connect multiple switches.
Cat5 cable supports speeds of 100 Mbps. 1000 Mbps Ethernet, of course, is designed to run ten times faster than that; luckily enough, it was engineered to be compatible with 90 percent of Cat5 installations. Having said that, I must also point out that some Cat5 cables don’t stick to the stringent specifications that 1000 Mbps Ethernet requires. The newer version of Cat5 cable is Category 5 Enhanced, or Cat5E for short. Cat5E is recommended for any new installation because it can easily handle 10/100 Mbps Ethernet and yet can handle 1000 Mbps Ethernet as well. Even if you’re using 10/100 Mbps Ethernet, you can upgrade someday to 1000 Mbps without having to worry about upgrading your cabling. You may also find Cat6 cabling in your network travels, which can also easily handle 10/100/1000 Mbps speeds.
