RJ45 Connectors and Standards - CompTIA A+ 220-1101 – 4.5 скачать в хорошем качестве

RJ45 Connectors and Standards - CompTIA A+ 220-1101 – 4.5

Let’s look at the connectors and standards used for network cables. Download PowerPoint: https://itfreetraining.com/handouts/a... Termination Standards Nowadays, standard network cables will contain eight wires grouped into four pairs of wires. For a connector to be used with these wires, they need to be terminated. There are two standards for terminating these wires, the 568A standard and the 568B standard. These standards are defined under the ANSI and TIA 568-D standard. On the left, I have used the 568A wiring standard, while on the right, I have used the 568B standard. In practice, when terminating patch panels, it's crucial to stick to a single standard throughout, to ensure consistency and reliability in your network infrastructure. However, for the sake of illustrating the distinctions between these two standards, I have uniquely terminated each side with a different standard to show the difference. The standards specify how wires are terminated. Regardless of the standard chosen, two of the wire pairs always terminate at the same location. However, the termination points for the remaining two pairs differ between the standards. Let's examine this more closely. 568A and 568B Shown here is the wiring for the two standards. To understand the difference, let’s first look at what is the same. Pair 1 for both standards and pair 4 are the same. What is different is, pair 2 on the 568A standard is the second set of wires from the middle. In the 568B standard, pair 2 has been moved to the top. Pair 3 in the 568A is at the top, and in the 568B standard, pair 3 has been moved to the middle. So, you can see there is not much difference, as only the orange and green pairs have been swapped. The 568A standard is backward compatible with older phone networks. However, the 568B standard is used worldwide more than the 568A standard. The 568B standard saw a lot of popularity with early ethernet networks. Some things to consider are that the 568A standard is recommended for horizontal cabling. Horizontal cabling is used to connect wall outlets and different networking cabinets together. Also, the 568A standard is a requirement for U.S. government contracts. There is a bit to consider here, but let’s have a think about what it means in the real world. In The Real World In the real world, don’t over complicate it. Essentially, just use the same standard the site is already using. Once a standard is being used, the site should continue to use that standard. If for whatever reason both standards are being used, make sure when you are connecting cables together, that they are using the same standard on both ends. If both ends of a cable are using the same standard, you are fine. Let’s have a look at what happens when you have a cable using one standard for one end and the other standard for the other end. Crossover Cable Utilizing different wiring standards on each end of a cable creates what is known as a crossover cable. This type of cable is specifically designed for a direct connection between two similar devices. For instance, when attempting to link two computers using a standard (straight-through) cable rather than through a network device like a switch, both will try to transmit and receive data on the same wires, leading to a communication mismatch. A crossover cable addresses this issue by swapping the transmit and receive wire pairs. The good news is, in the later 90’s, network adapters and network devices added technology allowing them to automatically detect and swap the necessary wires, eliminating the need for manual crossover cables. Thus, it is pretty likely that, if you connect two devices together, one of them will support automatic crossover. It only takes one device to support it to cause a swap when required. This is the reason you don’t really see crossover cables used nowadays, as you can simply use a straight-through cable. Therefore, if you inadvertently mix up the termination standards while setting up network cables, modern networking devices are often forgiving, automatically adjusting their transmit and receive pairs to maintain communication. Mixing termination standards is a clear sign of inexperience—a rookie mistake, so to speak. In upcoming videos, we will delve into methods for testing your network setup to ensure that everything is correctly configured, helping you avoid common pitfalls. Description too long for YouTube. Please see the following link for the rest of the description. https://itfreetraining.com/ap11/4c10 References “The Official CompTIA A+ Core Study Guide (Exam 220-1101)” pages 135 to 136 “Mike Myers All in One A+ Certification Exam Guide 220-1101 & 220-1102” page 745 Credits Trainer: Austin Mason http://ITFreeTraining.com Voice Talent: HP Lewis http://hplewis.com Quality Assurance: Brett Batson http://www.pbb-proofreading.uk