Ethernet networking is generally the least expensive, fastest, and least trouble free connection if you can run the wires to the locations where you want to use your computers. Even if you have support for wireless computing in your home, you will probably still use Ethernet for a few of the computers in your home.
TODO: This is what I wanted to say in this chapter, but somehow it seems to be missing something. perhaps it is too much or too little detail here and there. - Chuck
While this approach was simple and allowed a single long cable to be fed along the back of many computers, simplifying wiring costs, it did not work very well when one person disconnected the cable, effectively removing half of the computers from the network.
Twisted pair wiring and network hubs solved the problems of Coax cable Ethernet. In twisted pair, the computers are wired in a star configuration. Each computer had a dedicated connection back to the hub and when one computer was disconnected or had a problem, the rest of the network was unaffected. But because Ethernet was well established and the protocols which used Ethernet depended heavily on a broadcast medium, inside the hubs all of the ports were electrically connected together. One many hubs with activity lights, all of the lights seem to blink at the same time. This is because the traffic is being sent out on all of the ports at the same time. This means that a 10Mb/sec hub can only move 10Mb/sec total regardless of the number of computers connected to the hub. Hubs are still widely used in many low-traffic situations such as a home or small office when there are less than 10 computer systems connected to a network.
The next major step in the evolution of network equipment was the switch. Because the Ethernet protocol assigns a unique network address to each network card, it was possible for a switch to automatically "learn" which computer systems were located on which ports. When a switch first comes up, it acts like a hub, copying all incoming data to all the ports at the same time. But as the data is transmitted, the switch looks at the source address of each packet of data and makes a note which port it received the data. When a packet arrives for that workstation, the switch only copies the data to the proper port. Once a switch has identified which workstation(s) are on which port, the data is only copied to the appropriate port. This means that a 10Mb/sec switch with 8 ports is capable of up to four simultaneous data transfers at the same time for a total of 40Mb/sec overall. Some traffic (such as ARP packets - described previously) are special broadcast packets which are copied to all the connections of a switch. Switches work very well in networks from 5-250 computers because much more aggregate traffic can be moved through a switch. Switches are generally reasonably priced and have very good performance. In very large networks, their primary limitation has to do with how they handle broadcast traffic.
Switches have an added advantage in that most switches allow you to mix and match between different speed Ethernet equipment. The most common application of this is to use a combination of 10Mb/sec and 100Mb/sec Ethernet equipment in the home. Because switches are making dynamic connections for each packet, two 100Mb/sec computers can be moving data at 100Mb/sec, while two 10Mb/sec computers move data at the slower rate. A switch can even slow down the data, allowing data to be transparently moved between a 100Mb/sec computer and a 10Mb/sec computer.
In a home network environment a switch is generally preferable unless the cost gets too high. The price of an 8-port switch is pretty reasonable, but 16-port switches become more expensive because their typical application is in a business environment.
It is possible to connect a number of hubs and switches together to form your network. This can allow you some flexibility in wiring. For example, you can run one wire to a room, and using a hub within the room you can conect several computers to your home network. Using multiple hubs is called cascading. Cascading is made much simpler when your hub has an uplink port. Most of the ports on your hub are wired in the standard manner to connect to a workstation. One some hubs, one of the ports is wired both as a normal port and as an uplink port. You cannot plug a cable into both the uplink port and the corresponding workstation port at the same time. The five port hub pictured here can either function as a hub for five workstations or as a hub for four workstations with an uplink.
This diagram shows three four port hubs properly connected together with the maximum number of workstations attached to each hub. The top hub (root) has two workstations connected and uses two of its workstation ports up provide uplink connections for the lower hubs. Its uplink connection is not used. The two lower hubs, each have three workstations connected and their uplink port connects to the top hub. The workstation port port associated with the uplink port is not connected to anything.
When cascading hubs together, you cannot connect beyond three levels from the "root" hub to the end hub. The previous figure shows a two-level cascade. While this seems to be a somewhat limiting factor, with three levels of 24-port hubs, you can have over 10,000 computers. Also, switches do not have any "cascading" limitation like hubs. Because of this, you can think of any port on a switch as at "level zero" in terms of cascading.
In a hub, the only difference between a normal port and an uplink port is simply which signals are routed to which connectors in the cable. So "port 1" and the uplink port are the same port with slightly different wiring configurations. As a matter of fact, if you do not have an uplink port, you can use a normal port on the hub to make the uplink connection, but the cable must be a special cross-over cable or a cross-over adapter must be used. But most seasoned network professionals tend to avoid cross-over cables like the plague. The problem happens when your identical looking cross-over cable ends up in a box with a bunch of normal cables. For this reason, many cross-over cables are made out of red cable or specially marked in some other way.
The most common use of a cross-over cable is to create a network with exactly two computers and no hub. You cannot use a normal straight-through cable to connect two computers directly to each other. A crossover cable allows a direct connection. This is typically done when two people want to create a temporary network for the purpose of playing multi-person video games. You can also purchase cross-over adapters which connect two normal cables together to produce a cross-over cable. That way you never have to purchase any of the (dreaded) cross-over cables.
The actual rules for building Ethernet networks are complex and when completely describe take up a book with hundreds of pages. In this book, we distill those rules into "rules-of-thumb" which should be sufficient to build a reliable home network. To design a large network for a business with hundreds of workstations, you should consult a book such as XXX-XXX-XXXX.
Building a cable is easier and cheaper than you think. First you will need some supplies and equipment.
You may want to check the author's website (www.homenetworkguys.com) for some links to where you can purchase tools and supplies for wiring.
The following are the basic steps to install a crimp-on end to a Category-5 cable:
Cable testers range in cost from $50 to several thousand dollars. For a home network you can get by with the lowest price cable tester. The low pricer testers simply test that the poper wires are connected to the right pins. The more expensive testers can certify a cable as capable of handling data up to a certain speed.
If you would like a more polished look for your cables, you can purchase "plug boots" for each end of your cable. You slide the boot onto the cable before you terminate the connector. Once the connector is attached, the boot is slid over the connector and held in place with a small drop of glue. This way your cables can look exactly the same as the cables you purchase in a store.
Once you gain confidence building Cat-5 cables, it actually is fun and not too difficult. If you take your time you will probably find that your very first cable will work.
At some point, you may want a more polished appearance with some type of Cat-5 wall jack. Then you can run a short cable from the wall jack to the computer. To be even more "professional", you may want to run all the cables to a central location in a patch panel and then run patch cables from the patch panel to the hub or switch.
The only additional skill beyond wiring cables that is needed is the ability to string write through your home and the ability to wire Cat-5 jacks. like building cables, wiring jacks is relatively simple once you know the basics.
Most types of wall jacks will actually have a color coding so you know which wires from the Category-5 bundles are to go to which terminal. The steps to wire a jack as shown above are as follows:
In many ways, ategory-5 cable is pretty rugged and you do not have to treat it with kid gloves. But here are a few basc rules to follow as you run wire throughout your house:
Some builders are even providing home wiring as an option in many new homes. Home data wiring is often done by companies who specialize in home security, home theater, and whole house audio. A rough estimate for a professionally installed home data network is about $150.00 per network connection.
Some professional installers will suggest "structured home wiring". Most structured wiring consists of some combination of Category-5 cables and coax cable. The Category-5 cable can be used for data, telephone, security, low-voltage power, and home automation. The coax can be used for Cable television and satellite television. Either technology could be used for whole-house audio or video. A typical structured home wiring solution consists of two Catgory-5 cables and two RG6 Coax Cables. Some wiring even includes two fiber optic cables as well. the key idea is to install the wiring once and then upgrade the equipment in the basement and the equipment in each all outlet as your needs change.
If you are considering structured wiring, the biggest concern is the cost of the equipment to connect to the cables, both now and in the future.
An approach that we prefer is to emulate the approach used in most commercial buildings. Commercial installations prefer conduit for wiring because it offers the ultimate in long-term flexibility. Conduit also allows you to build only the capabilities that you need and no more. You can install a low-cost cabling solution now, use it for ten years. Then when some new technology becomes available and is inexpensive, you can remove your first solution and put in the new technology using the same condut.
Depending on a number of factors, a conduit solution may actually be significantly cheaper than a structured wiring solution even if it is installed by a professional. There is a very effective flexible plastic conduit that is very easy to install. Professional electricians laughingly call this "smurf-conduit" because of its blue color. But it has a number of signifcant advantages over wire installed directly in the walls.
When installing cable or conduit in a new home, there are a number of important things to keep track of:
As you plan where to put outlet boxes and conduit runs, try to think about future applications. Some of the locations that you might not think of right away include: