Friends who know more about the network know that Ethernet Cable has an "insurmountable" transmission distance of "100 meters". Whether it is a Category 3 Ethernet Cable with
effective transmission distance is 100 meters.
In the integrated wiring specification, it is also clearly required that the horizontal wiring cannot exceed 90 meters, and the total link length cannot exceed 100 meters. In other words,
100 meters is a limit for wired Ethernet, and this limit is the length of the link from the network card to the hub device.
capacitance, which leads to the attenuation and distortion of the network signal. When the signal attenuation or distortion reaches a certain level, it will affect the effective and stable transmission of the signal.
Category 5 UTP and Category 5 UTP are mainly for computer network services. According to the 100Base-TX regulations of Fast Ethernet, the communication rate is 100mbps. The time it takes for
100mbps Ethernet to transmit 1 bit of data (also known as "bit time") ) It can be calculated as follows: 1 bit time=1/100mbps=10ns
Data information is transmitted in the network, and when passing through different components, there will be a delay. The delay of the five types of UTP is 5.56ns/m. When designing Ethernet, it is
required to comply with a relay rule. This rule is also called the golden rule or 5-4-3-2-1 rule. This rule applies not only to 10mbps Ethernet, but also to Fast Ethernet. This rule requires that when the
ring collision delay should not exceed 512 bits, for a transmission rate of 100mbps, it is 5120ns. In the loop, the network components include cables, relay units, MAU, and DTE. Add their delays and
multiply them by two to get the loop delay. At the same time, the loop conflict diameter can also be calculated. According to this theory, it is possible to calculate the longest distance that the signal
can transmit to ensure that a minimum frame is sent. This is why the link span is limited to 100 meters.
When the Ethernet Cable exceeds 100 meters, because the conflict cannot be detected in time, the information packet damaged by the conflict is transmitted and received by the receiver. The
information packet is forced to be discarded because it fails to pass the verification. At this time, it is retransmitted. The mechanism is not activated, so it will cause packet loss. When the transmission
rate of the Ethernet Cable is lower than 100 mbps, in practical applications, the length limit of 100 meters can be relaxed for the Ethernet Cable. It must be stated that although this is actually effective,
it does not meet the standard. In the certification test, it must be explained, otherwise there may be some problems, such as product warranty.