What is the maximum transmission distance of each network cable?
Views: 17 Author: Site Editor Publish Time: 2022-02-14 Origin: Site
What is the maximum transmission distance of each network cable?
Friends familiar with network cables all know that twisted pair cables have an “insurmountable” transmission distance of “100 meters”. Whether it is a Cat5 network cable twisted pair cable with a transmission rate of 100M or a Cat6 network cable twisted pair cable with a transmission rate of 1000M, the longest effective transmission distance is 100 meters. In the integrated wiring specification, it is also clearly required that the horizontal wiring should not exceed 90 meters, and the total length of the link should not exceed 100 meters. That said, 100 meters is a limit for wired Ethernet.
When it exceeds 100 meters, the packet damaged by the conflict is transmitted and received by the receiver because the conflict cannot be detected in time. The packet is forced to be discarded because it cannot pass the verification. It is activated, which will result in packet loss. When the transmission rate is lower than 100 Mbps, the length limit of 100 meters can be appropriately relaxed in practical applications. Although this is effective, it must be stated that it does not meet the standard. In the certification test, it must be explained. Otherwise, there may be some problems, such as product warranty.
Maximum network cable distance during actual construction
It can be seen from the above why the maximum length of the network cable should not exceed 100 meters when using a PoE power supply. However, in the actual construction, to ensure the quality of the project, it generally takes 80-90 meters.
Please note that the transmission distance refers to the maximum rate, such as 100M. If the rate is reduced to 10M, the transmission distance can usually be extended to 150-200 meters (depending on the network cable quality). Therefore, the transmission distance of the PoE power supply is not determined by PoE technology but by the type and quality of the network cable.
Although a network cable with better quality can break through the 100-meter distance limit in actual construction, and the equipment can usually work, this approach is not recommended. Because some potential problems do not appear immediately but gradually appear over time, which can cause subsequent maintenance problems. The simplest case is the upgrade of bandwidth so that the equipment that can usually work at a distance of more than 100 meters will not typically work after the network speed is greatly improved.
The effect of network cable type and quality on transmission distance
Cat5 network cable is the most common standard network cable on the market, but the quality of different manufacturers varies greatly. Especially in the price-oriented environment in China, many manufacturers use copper-clad iron, copper-clad iron. The replacement of copper-clad steel leads to a decrease in the transmission distance of network cables and even network instability and packet loss. Equipment manufacturers often take the blame, which is wrong. Therefore, if you want to make the best effect of PoE, you must use a high-quality network cable, and the overall quality of the project cannot be affected by small losses.
Compared with Cat5 network cable twisted pair, Cat5e network cable has lower attenuation and crosstalk, which can provide a more solid network foundation and meet the needs of most applications (especially those that support Gigabit Ethernet 1000Base-T). Wiring), which brings convenience to the installation and testing of the network and has become a better solution in current network applications. The transmission characteristics of the CAT5e cable are the same as those of the ordinary CAT5E cable. Still, the CAT5e wiring standard stipulates that all 4 pairs of the CAT5e cable can realize full-duplex communication.
The transmission frequency of cables such as Cat6 network cable is 1MHz to 250MHz. At 200MHz, the Category 6 cabling system should have a large margin for the PS-ACR, which provides twice the bandwidth of Cat5e network cable. The transmission performance of Category 6 cabling is much higher than that of Category 5e standards and is most suitable for applications with transmission rates higher than 1Gbps.
An essential difference between Cat6 network cable and Cat5e network cable is that it improves crosstalk and return loss performance. Excellent return loss performance is critical for the new generation of full-duplex high-speed network applications. The primary link model is canceled in the Category 6 standard, and the wiring standard adopts a star topology. The required wiring distance is: the length of the permanent link cannot exceed 90 meters, and the length of the channel cannot exceed 100 meters.
There is no strict difference in transmission distance between Cat6 network cable and Cat5e network cable. That is, the maximum transmission distance of a single segment is 100 meters. Of course, the transmission distance of Cat6 network cable lines can be appropriately increased. The so-called 100 meters refers to the inability to meet the relevant technical indicators such as 1000M bandwidth after exceeding it, resulting in problems such as speed reduction.