Let's talk about twisted pair cabling. We've got some issues with twisted pair cabling because it's very susceptible to EMI electromagnetic interference, which comes from heavy machinery. We also have our if i radio frequency interference that comes from fluorescent lighting.
There's also a very short length of cable compared to other cable types. Before Attenuation sets in
with twisted pair cabling, you'll get about 100 m. For
with these limitations, it wouldn't be easy to guess that it's the most common cable type and use. But we love the words to been easy, and when they come together, that's what we go after.
Buildings are already wired for twisted pair cabling, and the cost of the cabling itself is cheaper.
When you're purchasing twisted pair cabling, it's important to be aware of where the cable is going to be run.
Many times we run cable in an area called the Plan. Um,
the plan, um, is the space between the drop ceiling and the true sailing.
We run cable there to keep things out of the way,
but there's a real danger if you have the sheathing made out of PVC,
it's important to make sure that the sheathing is going to melt, not burn.
We don't want to pull a fire from one area to another.
When you hear people talk about plenum cabling, this is what they're referring to
when we talk about cat three and cat five, that refers to the speed of cabling.
When I started out with networking, we were using cat three, so we got 10 megabits per second. By golly, we were happy to have those 10 megabits per second. We also walk to school on our bare feet uphill both ways in the snow. I'm finding myself becoming that crotchety old person to yell, Get off my lawn!
This was back in the day and we didn't have it easy the way that we do today
we went from 10 megabits per second to what we called Fast Ethernet, which was 100 megabits per second. But it was only fast Ethernet for so long until we got something faster.
Cat five e and Cap six gave us gigabit Ethernet or 1000 megabits per second.
Coming on the horizon, 10 gigabits per second is going to be the category seven.
We're going to continue to get faster and faster and when the cable maxes out, we'll get different cabling
in regards to, um, I an RFP. We do have shielded twisted pair.
We have what we call you TP and STP unshielded, twisted pair and shielded twisted pair. Of course, the goal with the shielding is to provide greater protection against the interference, but it's still twisted. Pair.
You can't run it down an elevator shaft, no matter how much shielding you put on it. So that's something you can keep in mind.
it's important to mention that there are several different types of cabling of twisted pair that can be used in various situations.
Straight through cable is the type of cable that you use to connect to different types of devices.
If I'm going to connect my system to a switch or switch to a router, I'm going to use what we call straight through cable
with the straight through cable. Each end is wired the same way.
There are two different pen out configurations T 568 A and T 560 b.
Honestly, I think you'll need to memorize this for the exam.
One of the things that we had to do back in the old days that we also have to do now is earn your stripes When you're low perching on the totem pole,
you get to sit down in the basement with the crippler and make hundreds of these straight through cables. That is a joyful event. Let me just tell you
the RJ 45 pin outs for T. 568 A and B
B is the more common of them. So if you don't have any more room in your brain to memorize both of them folks zombie but know that they could ask you for either one.
Remember straight through cables were the same way on both ends, and 568 A or B can be used as long as you use the same one on both ends. Its for connecting different devices.
Another type of cable is called crossover cable, and this is used to connect like devices, for instance, 52 computers that I want to connect really quickly in exchange some data. I could use crossover cables so the two systems on laptop to another crossover
crossover cable can also be used for a switch to a switch or a router through a router,
you can see the pin outs on each side. Side one is configured a certain way inside to is configured a certain way That's really necessary.
one of the problems with cable is if you wire them the same on both ends like you do with straight through cable. The sending pen is talking to the sending end, and the receiving end is listening for this receiving end
with crossover cable that flips. If we have straight through cable hub and a switch, those devices will kind of make that conversion for us. But if we're just going to like devices, we have to configure and pin it out as crossover.
another type of cabling is called rollover cable. Rollover cable has its own pin out. I know many of you are just sitting here thinking I cannot wait to memorize all of these. Sometimes with entry level exams, you'll just need to take some time and memorize things that seem very tedious. But I promise, as you become more and more involved, you'll find that these basics really do help you with the understanding.
a rollover cable is going to be used if I'm connecting my laptop to the console of a router. It's a flat cable. All the other cables look exactly like you can't really tell just by glancing at them. But a rollover cable has an RJ 45. Looks like it's been rolled over by a steam roller.
It's a cable that you plug the RJ 45 into the router, and that's how you can connect directly and make configuration changes.
Router switches often have a console cable for physical connectivity
if you're not going to be promoting, and physical connectivity really is a much more secure option