[Data Map]

Hello, everyone. I'm Xiao Sheng from the Urban and Rural Economic Network to answer the above questions. What will happen if the transmission distance of the network cable exceeds 100 meters (why can't the transmission distance of the network cable exceed 100 meters)? Many people still don't know. Now let's have a look!

Many people who do network engineering know that the transmission distance of super five network cables can only be 100 meters in general, and the stable transmission of data cannot be guaranteed if the distance exceeds 100 meters. Packet switching is serious or not at all, but why it can only be 100 meters? Few people can say why, and many friends have tried to use more than 100 meters in the project, Now let's talk about what happens when the transmission distance of the network cable exceeds 100 meters? I hope the following content can help you. Let's have a look!

What happens when the transmission distance of the network cable exceeds 100 meters

Many people who do network engineering know that the transmission distance of the super five types of network cables can only be 100 meters. If the distance is more than 100 meters, the stable transmission of data cannot be guaranteed, and packet switching is serious or impossible. But why only 100 meters? Few people can say, and many friends have tried to use more than 100 meters in the project.

Before we talk about this problem, we need to clarify a concept. The 100m refers to the distance between two electrical ports of the directly connected network equipment, including network modules and distribution frames.

We know that digital mode uses binary to transfer data, namely 0 and 1. When the network cable transmits data, there is current passing through it, which will generate voltage. We transmit data through voltage. We define the voltage between 5V and 15V as "1", and the voltage between - 5V and - 15V as "0". Transmission of different voltages represents different numbers in the binary system. We use the voltage of - 3V to 3V as a sign of abandonment. From 3 to 5, there is a tolerance space of more than one point. Because - 3 or 3 will be abandoned, it cannot be counted as 2.

According to the above principle, we can roughly calculate the maximum length of the network cable. As we all know, the national standard network cable has a core diameter of 0.5mm, and the area of a single conductor is 0.1965mm2. The resistivity of the copper wire at room temperature is about 0.0175, and the characteristic impedance of the network cable is | Z |=100 Ω.

Now, according to this formula, resistance=resistivity times wire length/wire area, we can calculate that the maximum length of network wire is 112 meters.

Of course, this is a simple conversion, not very rigorous. In fact, the speed of data transmission and the capacity pit formed by the length of the network cable (the longer the parallel capacitance is, the slower the speed is), as well as the bending and pressing of the network cable, will affect the actual length. In consideration of the redundancy of two end jumpers and future line aging in the actual project, it should not exceed 90 meters as far as possible, especially when POE cabling is involved

This article has been explained here for you, and I hope it will be helpful to you.