If you are looking to buy ethernet cables and don’t know if you should get crossover or straight-through cables, you are not alone. We get this question, “what is the difference between straight-through and crossover cables, and which one do I need” all the time. So we have decided to settle this case once and forever. In this article, we explain the difference between both types of cables and their uses. But before that, let’s briefly explain ethernet cables, and the T568A and T568B wiring standards. Because you can’t understand the difference between straight-through or crossover cables without understanding these.
What is an ethernet cable?
Ethernet cables are networking cables used for high-speed data transmission. These cables feature 4 twisted pairs of conductor wires. The twists in the conductors help reduce interference and crosstalk. The types of twisted-pair cables are called categories. The most popular categories are Cat6a, Cat7, and Cat 8 cables.
What are T568A and T569B wiring standards?
If you have ever found yourself wondering about the configuration of any cable and not just ethernet, you have probably noticed that they follow a certain protocol or standard. Meaning, engineers and pioneers of cables define certain methods to integrate cables. And in most cases, these methods are modified.
T568 A and B are the wiring standards defined by TIA/EIA for terminating twisted-pair cables in an 8-pin 8-contacts (8P8C) RJ45 jack. Both standards are similar but not the same. In fact, T568 B is the revised protocol and is used more commonly. The difference between both protocols is the difference in the order in which the 8 conductors are terminated in an RJ45 jack.
What is a crossover cable?
An ethernet crossover cable is used to connect the same or similar devices in a network. For example, if you need to connect two computers or other similar electronic devices, you will need a crossover cable.
It follows the T568 A wiring standard on one end T568 B standard on the other. It reverses the direction of signal transmission which is necessary to exchange data between different devices. Essentially, this type of cable is a patch cable that connects different devices in a network and it is mostly used as an alternative to wireless connections.
Note that the internal wiring of the ethernet cable is the same as in the crossover cable. What is different is the order of pinout in the RJ45 jacks.
Uses of crossover ethernet cables
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- Switch to switch
- Switch to hub
- Hub to hub
- Router to router
- Router Ethernet port to PC NIC
- PC to PC
What is a straight-through cable?
An ethernet straight-through cable is used to connect two different devices. For instance, if you need to connect your laptop to a router or switch, you will need a crossover cable.
The cable follows the same wiring standard on both of its ends. It is either T568 A or T568 B. Note that if one end of the cable is terminated according to T568 A standard, the other end also must be terminated according to the same pattern.
Uses of straight-through ethernet cables
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- Switch to router
- Switch to PC or server
- Hub to PC or server
Difference between Crossover and Straight Through Cables?
As mentioned, the main difference between a crossover and straight-through cables is the termination protocol on both ends of the cable. To reiterate, the crossover cable is terminated according to T568 A wiring protocol on one end and the T568 B wiring protocol on the other.
The straight-through cable on the other hand follows the same wiring protocol on both ends. It is either T568 A or B.
Now, because of the particular protocols followed in terminating the cable in an RJ45 jack, the uses of the cables also vary. Hence, both types of cables have different uses.
Which cable to buy? Crossover or Straight Through?
Choosing between a straight-through and a crossover cable is simple. In fact, it is dictated by your requirement. If you need a cable to connect your computer to the router, you need a straight-through cable. And if you need to connect similarly or the same devices, go get a crossover cable.
