Introduction
More and more we are bombarded with networking products whenever we go into an electronics store or point our browsers to an electronics website. There are a myriad of products available, all claiming to be exactly what we need, but there are a couple important questions that need to be answered before we buy anything. What do all these different products actually do? What do I need for my home network? In this article I will explain network cards, switches and hubs, routers, modems, and wireless products.

Table of Contents

• Introduction


• Network Cards


• Switches and Hubs


• Routers


• Modems


• Wireless products


• Integrated Products


• What to Buy


• Networking Diagrams


• Recommended Parts


• Setting It All Up


• Further Reading


• Conclusion

Network Cards
The first thing you need to get connected to the internet, or any network for that matter, is a network interface card, or NIC. A NIC connects your computer to a network. They can be connected to your computer via a PCI slot, but these days most are built into the motherboard, so end users usually do not need to purchase a separate one. There are a couple different kinds of NICs that you will find on the market today, 10/100 cards, also called fast ethernet, and Gigabit cards. 10/100 cards communicate at speeds up to 100 Megabits per second, and Gigabit cards communicate at up to 1000 Megabits per second, which is 1 Gigabit per second. If you are purchasing a separate network card, I would suggest getting a Gigabit card, if you can justify the higher price. Gigabit networking is becoming more prevalent every day, and a with Gigabit card you will be ready for the future.

Before any further discussion of networking equipment, we need to clarify network speed ratings. Network speeds are generally specified in terms of bits, e.g. Megabits and Gigabits. Hard drive sizes and real-life transfer speeds are generally specified in terms of bytes, e.g. Megabytes and Gigabytes. The difference between these two ratings is simple, but something that must be kept in mind when thinking about how fast the network will run. There are 8 bits in every byte, meaning that to find out how bytes per second could theoretically be transported by a network rated at 100 Megabits per second, we divide by 8 and get 12.5 Megabytes per second. The abbreviations for bits and bytes can also create confusion. In abbreviations, a bit is specified by a lowercase b, and a byte is specified by an uppercase B, so 100 Mb/s is the same speed as 12.5 MB/s. Hopefully whenever you encounter these abbreviations they are used properly to minimize confusion, but this is often not the case on internet forums.

Switches and Hubs
Switches and hubs perform the same function, but in different ways. They both have multiple ports to provide a physical connection between multiple computers or other network elements. Hubs are outdated technology, but most people still hear the term fairly frequently. A hub works by repeating traffic that comes into any of its ports to all of its other ports. This means that computers connected to a hub must share its bandwidth. Five computers connected to the same 100 Megabit hub and communicating simultaneously can each only use 20 Megabits of bandwidth. A switch, on the other hand, only passes traffic to the ports where it needs to go, so each computer connected to it can take advantage of the full bandwidth of the switch. Five computers connected to the same 100 Megabit switch and communicating simultaneously can each use 100 Megabits of bandwidth. Think of the hub as similar to a four-way stop and a switch as similar to a freeway system. Both connect several different roads together, but in different ways. With the four way stop all cars must pass through the same place, one at a time. A freeway system can handle all the traffic simultaneously and each car can have its own entrance and exit from the freeway. Switches also have an important advantage over hubs in the area of security. Since a hub simply repeats all traffic to all of its ports, every computer connected to it can eavesdrop on data meant for other computers. Think of this aspect like a room full of people trying to talk to each other. Everyone could simply shout, or they could walk over and whisper in each other’s ears.

 It is difficult to find hubs on the market today, and there few reasons to get one. Switches have become much cheaper in the last few years, removing the price advantage that hubs once had.
 
One last note about switches: there are two common speeds you will find on the market today, just like with NICs. 10/100 switches have been around for a several years and can be found for very reasonable prices, while Gigabit switches are fairly new and command a price premium. For most people, the price is not worth it. 100 Megabits is more than ample speed for most network applications. One of the few places where Gigabit speeds are really useful is if you do large file transfers on a regular basis. To achieve Gigabit quality speeds, your network machines will need to be equipped with Gigabit network cards, along with the Gigabit switch. Keep in mind though, because of hard drive speeds and the speed of internal communications of your computer, you will only actually see a maximum of about 300 Megabits per second during file transfers between two computers connected to a Gigabit switch.

Routers
A router does exactly what its name implies; it routes traffic between different network segments. Routers control the internet as a whole by managing the flow of traffic around the world. This is all quite complex, and the people who designed the system were very brilliant, but understanding the type of router you will have in a home network is much easier. A home router enables you to share one internet connection among multiple computers in your home. It does this through something called network address translation, or NAT. In simple terms, NAT translates the single IP address that your ISP provides into multiple IP addresses in your home network; one for each computer. This type of translation also provides a basic hardware firewall for your network. When you are behind a router, all unsolicited incoming connection attempts to your home will be dropped, while all activity that you initiate, such as browsing the web “just works” without any extra effort on your part. Being behind a router is probably the single most important thing you can do to keep your computers safe from malicious internet traffic. In addition to the above, the average consumer router usually has an integrated a 4-port switch, so a router is often the only extra piece of equipment necessary to share an internet connection between a few computers on a home network.

Modems
In the old days, a modem was the device that enabled you to use a dial-up internet connection. These days we use different sorts of modems, usually either a cable modem or a DSL modem. A modem simply converts one type of signal to another. It will convert the cable or DSL signal coming down your cable or phone line into standard ethernet traffic, which your computers and other networking devices can understand. Although the internal workings of a modem can be complex and interesting if you’re a very technical sort of person, from the perspective of the average consumer that’s really not much that needs understanding. In one port of the modem you plug in the cable or phone line, and in the other port you plug in an ethernet cable which can either connect directly to a computer or to another network device such as a router.

Wireless Devices
There are two types of wireless devices on the market today, wireless access points (WAPs) and wireless routers. Wireless routers are far more common. Both of these devices allow computers to connect to them wirelessly. The difference is that a wireless router incorporates all the functions of a router, such as sharing an internet connection and automatically assigning network addresses to all the computers on the network. Wireless access points differ from wireless routers in that they can incorporate more advanced wireless functions, such as extending your wireless coverage by acting as a repeater for an existing wireless network. Although wireless routers incorporate more general functionality than access points, strangely enough, access points tend to be slightly more expensive.

Currently, there are many different wireless standards on the market. This is a very active segment of the market and standards seem to be in a constant state of change. There is much debate over the finer points of each standard, but a few generalizations can be made. 802.11b is quite old and not a very good performer compared to newer standards. 802.11g has mostly replaced 802.11b and performs much better and faster. This standard has been around for a while and has plentiful support by a wide variety of devices. A new standard coming out soon is 802.11n. Although products claiming to be “Draft n” are currently on the market, the standard has not yet been ratified as of the writing of this article. Most reviewers of Draft n equipment are disappointed by the performance of these products and recommend holding off on them until the standard is officially ratified.

There is one final category of wireless standards that does reliably offer better performance than the widespread 802.11g products. The category is referred to by a few different names, usually “Pre n” or “MIMO.” These products don’t follow any official standard, but use proprietary technologies developed by their manufacturers to offer better performance than existing 802.11g products. The drawback to these products is that one must purchase matching products to achieve the better performance. The wireless router or access point and all wireless network cards for laptop or desktop computers must be specifically made to work together. Currently this is probably the best performing option for a wireless network, but the best long term advice is to wait for the official 802.11n standard to come out.