Ethernet network cables |
the Ethernet network cables used in local area networks and I'm referring to twisted pair cables. These are the Ethernet cables that you'll find as you connect your computer to your router or modem, you can have internet access. One end of the cable plugs into your computer's network interface card and the other end plugs into the network port of your router, switch, or modem, depending upon what you're using. Now Ethernet twisted pair cables come in two different types. The first type is unshielded twisted pair, which is by far the most common type of cable that is used today. Unshielded twisted pair consists of four pairs of color-coded wires twisted around each other. The wires are twisted to prevent electromagnetic interference or crosstalk. This type of network cable is what most people use in their home or business. And the second type is shielded twisted pair. Shielded twisted pair is very similar to unshielded twisted pair, except that it has a foil shield that covers the wires. And this shielding adds an extra layer of protection against electromagnetic interference leaking into and out of the cable. This type of cable is mainly used for industrial purposes and not so much in a home or business. So if you were the kind of person that is going to make their own custom cables for your network, typically you would buy a bulk roll of twisted pair cable and then you would have to wire them correctly and then attach RJ45 connectors to each end. So to do this you would have to remove the protective sheathing at each end of a network cable to expose the wires. And this is done by using a cable stripper. The cable is inserted into the cable stripper and then the outer sheathing is removed to expose the wires. And then you would insert the cable into a wire crimper to attach an RJ45 connector. But before you touch the connector, the wires in the cable have to be arranged in a certain order. And that order will be different depending upon the purpose of the cable. So for example the most common types of twisted pair cables that are used in a local area network, are straight and crossover cables. And these two cables have two different purposes. So let's talk about the
Ethernet network cables |
wiring order that these twisted pair cables use. And there are two different wiring standards that are used. One standard is called 568A and the other standard is 568B. And on the screen you can see the wiring order for both the A and B standards. The orders are based on the color of the wires. for example the 568A standard is wired in this order: white green, green, white orange, blue, white blue, orange, white brown, and brown. And the 568B standard is wired in the following order: white orange, orange, white green, blue, white blue, green, white brown, and brown. So the only difference between the A and B standards is the green wires are swapped with the orange. And it doesn't really matter which standard you use. Both standards do the same thing, but here in the U.S. most people use the B standard. So whether you choose the A or B wiring standard, if both ends of the cable are wired using the same standard then this is known as a straight cable, which is also known as a patch cable. A straight cable allows signals to pass through from end to end. This is the most common type of cable that's used in local area networks. A straight cable is used to connect computers to hubs, switches, routers, or modems, or in other words, it's used to connect dissimilar devices together. So as I said before this is by far the most common cable that's used on local area networks. these two straight cables here do the exact same thing. The only difference is that one cable is wired using the A standard and the other one is wired using the B standard. let's talk about a crossover cable. Now a crossover cable is also used on local area networks but it's not as common as a straight cable. A crossover cable is created when both ends of the cable are wired using the two different standards. For example, one end is wired using the A standard and the other end is wired using the B standard. Crossover cables are used to connect two similar devices together. For example, crossover cables are used to connect two computers directly to each other without
Ethernet network cables |
using a hub or switch and they can be also used to connect hubs to hubs, or switches to switches. they are used to connect two of the same devices together. Now in addition to talking about the different types of twisted pair cables, we also have to talk about the categories of twisted pair cables. And these categories are called CAT 3, CAT 5, CAT 6, and CAT 7. And the difference between these is a maximum speed that they can handle without having any crosstalk or interference. The numbers of these categories represent the tightness of the twists that are applied to the wires. And as you can see on the illustration of the categories and speeds of the different twisted pair cables as you can see, the speed ranges from the lowest category which is CAT 3 at 10 megabits per second and all the way up to CAT 6a and CAT 7 which has speeds of 10 gigabits per second. Now most networks today would use at least CAT5e on their networks. Because most networks would be running at least at gigabit speeds. So CAT 3 and CAT 5 are slower than gigabit and are pretty much obsolete today. But of course if you're running a network that can handle 10 gigabit speeds, you would have to use CAT 6a or CAT 7 on your network. But even if you have an older network that's running slower speeds, you can still use CAT 7 because it is backward compatible. CAT 7 is actually a shielded twisted pair version of CAT 6a. And finally the latest version is CAT 8. Now CAT 8 is the ultimate copper cable. It's a shielded twisted pair cable which has a delivery speed of 40 gigabits per second up to a distance of 30 meters, which is 4 times faster than CAT 6a or CAT 7.
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