Wiring a Home Network

Yes, this was copied off of a web page but I wrote the web page

The Theory

Most wiring in your home is probably serial or daisy chained. In other words, the wiring goes from one device (such as a phone jack) to another. It is done this way because it is cheaper for the builder (less wire). Ethernet, however, will not work daisy chained. It requires a star or hub-n-spoke configuration where the center is a device called a hub or a switch which links the various devices together. The advantages of this are easy to understand. Instead of having to go into the walls to change your wiring configuration, you just go to the hub and move cables around as needed.

Now, there are two main standards for Ethernet, the 10 Mbps defined by IEEE 802.3 and the 100 Mbps defined by IEEE 802.3u (FastEthernet). In the past, 100 Mbps was quite a bit more expensive but now, the cost difference is so negligible that going 10 Mbps would be a waste of time. Both of these standards run over a cable called UTP (unshielded twisted wire pair). There are several category's of UTP, the most popular are Cat 3,5 and 5e. Cat 3 is mainly used for phone lines and 10 Mbps ethernet. Cat 5 and 5e are the most popular today. Both can be used for phone lines and 10 Mbps application, Cat 5 can also be used for 100 Mbps FastEthernet. Cat 5e can be used for all of the above plus Gigabit Ethernet (1000 Mbps). To somewhat future proof your house, I would recommend Cat 5e.

Planning

It's always a good idea to at least have a plan, especially if you are going to be drilling holes in your house and cutting into your walls. Now, to develop this plan, you need to have an idea how your home was build. Go up into your attic and take a look around, figure out where you can get to without killing yourself and where wireless would probably be a better idea.

Okay, the way this is going to work is that all of the cables are going to go from where you want them to some central point in a hub-n-spoke manner. Negotiate with your wife on giving you a shelf in that closet in the middle of everything. The closer this closet is to where you want your jacks to be, the shorter your cable runs need to be. Remember that all of you runs will terminate here so try not to pick a place that is terribly difficult to access.

For the drops, it's a good idea to avoid exterior walls (they usually will have a bunch on insulation and possibly some extra 2x4's running through them horizontally). If you see an exterior wall with a power line running down it and are thinking about just following it down, don't. It will kill your network performance.

One more thing, run more cables than you need. It is just as hard (and only slightly more expensive) to run 4 cables to a 4 port wall plate than 1 cable to a 1 port plate.

Materials

This is what you'll need to wire your home:

  1. Cat 5/5e Twisted Wire Pair: This is usually sold in 500' or 1000' spools. I found 1000' of Cat 5e plenum on Yahoo! Shopping for $150.00.
  2. RJ-45 Keystone Jacks: These are the actual ports that you will plug your computers into.
  3. Wall plates: You can buy these for 1 to 6 ports. I used 4 port wall plates.
  4. Wall plate mounting box- low voltage: These things will be what you use to mount your wall plates on. Open up a cable wall plate to see what they look like.
  5. Patch Panel: This is what you will use in your wiring closet. They come in 16 - 96 port models and they are basically a huge wall plate. You will need some sort of mounting bracket to mount these things.
  6. Hinged Wall Bracket: This is what I used to mount my patch panel. It is basically a miniture 19" rack that mounts into the wall. You can just use extra wall plates and keystone jacks but if you are running more than 8 cables, this is probably a better option
  7. 110 type impact tool: This is what you will use to connect the Cat 5 cable to the keystone jacks and the patch panel.
  8. Cyclone Wire Stripper: This tool is great for stripping Cat-5. You could use an ordinary wire stripper but this is far better as it will always cut at the perfect depth so it won't cut the insulation of the inner wires.
  9. Dry wall saw: Don't use a jig saw, it may get away from you and then your wife will kill you.
  10. Miscellaneous: You are going to need other things like measuring tape, stud sensor, drill, etc.

Let's Do It

Finding the studs

I found stud sensors at Home Depot from $15 - $30. Get the expensive kind. It will eliminate a bunch of guess work. Now, on my walls, I kept finding what I initially thought were studs running horizontally about midway through the walls. This scared me to death but it turns out I was picking up the joint between two sections of vertically stacked drywall. You will find that the studs are located between 16" and 22" apart. It is important to get an idea of how far apart they are in each wall so you know your margin for error (you don't want to cut your hole for your wall plate between different studs than you drilled for the cable drop). Try to find a set of studs that don't have any power lines running through them as this will reduce interference on your cables. The stud sensor I bought also had a wire locator. This is great for finding where those power lines are hiding.

Drilling the holes

Once you've picked where you want your wall plate, you need to go up into your attic and drill your hole in the joist (the 2x4 that runs above the wall). You are going to need some measurements of various landmarks in your attic to find where the hole should be drilled. I used a 1" bit for my holes. I found that it can hold 8 cables. I ran 4 through each one. It is better to drill too large a hole than too small of a hole or your joists may end up looking like Swiss cheese before you are done.

I started drilling with a cordless drill but I soon realized that it didn't have the power to drill the 1" hole so I switched to a regular drill. Save yourself some time and make sure you have one. One problem I ran into drilling the holes was over our two extra bedrooms. There were 2 2x4's running 6" above the joist I needed to drill through. Since I couldn't get my drill and bit above the joist and under the 2x4's, I had to make another trip to Home Depot to get a 14" long bit and a 6" extension. I had estimated that I only needed 14" to get through the joist but after my thrid trip to Home Depot, I realized to err on the side of excess. It turns out I needed that extension.

Now, before you start drilling, you probably will want to turn off most of the power in the house at the breaker. I turned off all the breakers except for some outlets on the other end of the house and ran an extension cord into the attic to power the drill and a light. It really would have sucked to drill through a live power cord running under a joist.

Remember to drill your holes before you cut into the wall. If you realize you made a mistake, it is a lot easier to cover up before you cut your holes in the walls.

Cutting up the walls

This is the part of no return. Make sure your mesurements are correct - measure twice, cut once. The wall plate mounting boxes should have a template for cutting into the wall. Take some measurements of the height of the other outlets on your walls and calculate where your cut should be (remember, the wall plate will be larger than the mounting box). When you actually draw your lines, use a pencil or something you can get off the wall if you realize you made a mistake. Also, use a level - it may look even when you eye ball it but it won't when you cut it.

Before you start cutting, it may be a good idea to take a needle and a tac hammer and make sure that you aren't about to cut into a stud. If the needle can get through the wall, you should be OK.

Now, to get the dry wall saw (looks like a large steak knife) into the wall, you can either use a drill or simply push. Pushing worked fine for me. Before you finish the cut, you may want to hammer a nail into the section you are removing so you have something to hold on to to keep the cut out from falling into the wall.

For the patch panel, the mounting bracket had a 8" oval hold in the middle of it. I simply cut that oval into the wall for the cables to come through.

Dropping the cables

If everything went OK, this should be easy. Go up to your attic with a string and a weight tied to the end (you wife's wedding ring should work) and lower through the hold in the joist. Have someone on the other end pull it through the wall. Make sure that the string doesn't fall through either hole by tying it to something on either end.

Next, cut your cables. Get a good estimate of how much cable you need. I have 10' walls so I used a minimum length of 24' (20' to get through the walls and an extra 2' on each end to give me some slack for punching it down into the patch panel and the jacks) plus whatever length I would have to transverse through the attic. When you are done, the extra slack will be pulled into the attic giving you some liberty on how to position your cables to avoid power cables. Now label both ends and the middle of your cables. Come up with a numbering scheme and use it (1 - 16 worked for me as that is how my patch panel was numbered). Use masking tape or something for the labels. Make sure they don't fall off and you can read them. If you lose track of your cables, it will be a nightmare finding them again.

If you are doing multiple drops to the same wall plate, tape the end of the cables together so you can run them all with one drop. Now, tie the end of the cables to your string using masking tape or something. Make sure it is secure (you don't want it coming off in the wall). If it was difficult getting the string though the wall, you probably want to tie another string to the attic end of your first piece that way if you decide to drop more later, your string is still there. Make sure to affix both ends to something such as the mounting bracket and a 2x4 in the attic.

Now, remember these rules when working with Cat 5:

  • Never pull Cat 5 with more than 25 lbs. of force. It will damage the cable.
  • Never kink a cable - the tightest loop in a cable can have a radius of 1" (or a diameter, I can't remember - just don't do it).
  • If you have to cross a power line, cross it at a 90° angle. Never run parallel with a power line

Punching down the patch panel

I suggest punching down the patch panel first as it will make testing go faster. After I had dropped cables for one room, I punched down all of the cables for the patch panel. This way as soon as I finished punching down a keystone jack, I could test the connection.

Now, punching down is probably the most tedious part in the process. You may want to do some test punch downs on between a couple of keystone jacks an a 1' length of cable before you try it on your cables in the wall.

Here are a few rules for punching down the cables:

  • Seperate the pairs as little as possible - once you remove the outer insulation, you will see 4 pairs of twisted wires. Try and keep them twisted.
  • Have as little wire outside of the outter insulation as possible. I believe the maximum is 1" which is probably what you'll need on the patch panel but much less on the keystone jacks.
  • There are 2 main wiring schemes that dictate which color wire goes to which terminal (T568-A and T568-B). Obviously the electrons don't know the color of the wires as long as you are consistent on both ends. However, it is important that you don't mix pairs. In other words, if pins 1 and 2 are for the blue/blue-white pair, you can't use the blue wire from the pair and then use a brown-white wire from the brown/brown-white pair.
  • The impact tool will have an end labeled "cut". The cut end goes to the outside of the terminal. This end will cut the excess wire off so if it facing the wrong way, you just cut your cable - whoops
  • The impact tool may have a knob for choosing low or high impact. Use low - I tried high and it never worked for me.
  • Make sure you have a hard surface to work on and the impact tool is vertical.
  • Bring the cables in parallel to the terminals, don't come in from above.

And here are the two wiring schemes:

T568-A
Pin 1: Green with white stripe
Pin 2: Green
Pin 3: Orange with white stripe
Pin 4: Blue
Pin 5: Blue with white stripe
Pin 6: Orange
Pin 7: Brown with white stripe
Pin 8: Brown


T568-B
Pin 1: Orange with white stripe
Pin 2: Orange
Pin 3: Green with white stripe
Pin 4: Blue
Pin 5: Blue with white stripe
Pin 6: Green
Pin 7: Brown with white stripe
Pin 8: Brown



Your patch panel and your keystone jacks should be color coded for both schemes so there is no question about which wire goes where. Remember that there is no reason to use T568-A over T568-B.

Once you've finished punching down your 8 wires, you may find that the impact tool didn't completely cut the excess wire. Just twist the wire around until it comes off.

Punching down the keystone jacks

This is a bit easier than the patch panel because of the way the terminals are lined up (2 rows of 4 instead of 1 row of 8). Make sure you use the same wiring scheme you did for the patch panel. As with the patch panel, make sure that the cable comes in parallel with the terminals (so that it runs between the two rows. As you finish each cable test it!

Testing

There are numerous cable testers available that will do things like tell you which wire is going to which cable. I just used a laptop and a hub to test the cables. If the light on the hub comes on, you're good. If it doesn't, for the love of god, make sure that it isn't your laptop, your hub or the 2 cables you are using to make the connection between the hub and 1 connector and the laptop and the other are working! Also, make sure that you have them plugged into the right cables (did you label them?).

If your cable doesn't test okay, first check the wiring on the patch panel and the keystone jacks to make sure the right wires are going to the right pins, if you find an error, you can pull the wires out of the terminals, re-strip the cable and try again.

If everything looks okay, it may be a bad connection (this is where a cable tester would have come in handy as it will test DC connectivity). Try redoing the keystone jack and retest. If it still doesn't work, try the redoing the patch panel. Before you start pulling wires, check again that you are using the right ends. You will kill yourself if you try repunching a cable 3 times only to find out that you were using cable 13 in the hub and cable 9 on the laptop.

Patch Cables?

If you had a nice little network with say 2 computers, a hub, a router and a cable modem requiring 4 patch cables (the cables with the male connectors on the ends), you are going to realize that you will need at least 3 more to use your new wiring as you will have the extra connections for your hub in the wiring closet. You can go ahead and spend $1 - $7 on some cables or you can think to yourself, "Hmmm, I've got 300 feet of cable right here; maybe I should make my own."

Making cables is cheap but a pain. You are going to need an 8 wire RJ-45 crimp tool (about $20) and some RJ-45 modular plugs (cheap as dirt). See crimping Cat-5. There is also a good tutorial with pictures on how to make patch cables at http://www.lanshack.com/highlights/makepatch.htm. It takes a bit of practice to get it right but after wasting a couple of connectors, you should have it down.

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