Network cable Common Fault Analysis

During project installation, due to the limited conditions, the Network cables are all made on site. Generally, you do not need to perform an instrument test. You only need to use the indicator lights to preliminarily determine whether the network cables are turned on or off. However, the indicator lights sometimes do not reflect the network cables, some soft faults existing in the production of Network cables cannot be found at the moment. After a while, they will be gradually exposed. The following are problems found during data maintenance in recent years.
1. Place the green line at 5th feet or other positions.
(White orange, orange, white green, blue, green, white blue, white brown, brown)
(White orange, orange, white green, blue, white blue, green, white brown, brown)
This is a completely wrong method, that is, one end adopts the standard practice, while the other end accidentally inserts the Green Line into other locations when creating the network cable, especially when the Green Line is easy to insert to the position of Step 5, during maintenance, it is found that the cables produced in this sort of line can also light up the indicator and sometimes ping the network. However, such cables may suffer infinite problems when used in data communication.
In addition, there are several non-normal line Sequence Network cables that can also be pinged, but the problem is exposed after a period of time.
For example, if a company uses fiber optic network and fails debugging several times, try another switch port. When you pull the network cable down, you can see the problem, originally, the production staff only used 4 cores to create a network cable, and one core was inserted into the 5-pin position.
For example, if a unit is interrupted every other day, it may take some time for the maintenance personnel to plug in the network cable. It may be because the contact between the crystal head and the slot is loose, when you pull the network cable down, the line sequence is confused. One end adopts the standard practice and the other end becomes (white orange, orange, green, blue, white green, white blue, white Brown, brown ). However, the network cable created in this sort of line is actually accessible!
The probability of occurrence of such errors is still very low.
2. Place the Green Line in the position of 4th feet.
(White orange, orange, white green, green, blue, white blue, white brown, brown)
(White orange, orange, white green, green, blue, white blue, white brown, brown)
This is the easiest place for beginners to make mistakes, that is, to put the white green line and the green line together, which will cause crosstalk and reduce the transmission rate. In addition, it cannot be checked by an instrument, because its end-to-end connectivity is normal, and it will not cause network interruption, but the network is slow, it is certain, serious cases may also cause intermittent interruption. Troubleshooting in the future is also very troublesome, so no matter what the problem is, you cannot create a network cable.
3. Create a network cable with only 4 cores.
Theoretically, only 4-core is enough for data transmission. However, in actual maintenance, it is found that there are still some problems with the network cable made of only 4-core, the problem of a long network cable is exposed. Since there are 8 cores in the network cable, why should we only use 4 Cores during the production?
4. network cable cover
The main function of the network cable protective cover is to prevent the network cable from being pulled out, but it is tight in some network card locations. With this protective cover, it will be unable to be plugged in to the end; there are some relatively hard protective covers, instead, the crystal head's snap-on won't be able to hit the ground, making contact less tight.
5. Poor network cable Quality
At ordinary times, we may not care much about the quality of the network cable. Generally, we usually use less than 10 network cables, so the impact of poor network cables is not obvious, however, when wiring the LAN, if the network cable exceeds 30 meters, we need to pay attention to the network cable quality.
For example, it is good to use a notebook to test on each port during debugging in a certain organization, but the problem is solved after changing to the user's own desktop computer. packet loss may occur from the near-point detection, which may not work far away, the final check shows that the electrical characteristics of the network cable do not meet the requirements.
6. RJ45 crystal leaders are not close
Inferior RJ45 crystal head is mainly spring piece is not close, often happen not compacted, at that time is through, after a period of time again when the phenomenon of breaking.
RJ45 crystal will gradually become loose when it is worn against the device slot for a long time. If we have no network cable at hand, we can change the two heads because the physical location has changed, it can often be turned on again.
In addition, if the clip on the crystal head is not flexible, it is easy to remove these cables from the switch with full cables, resulting in new faults.
7. The quality of the crimping tool is not enough
Considering the cost, most of our current applications are made in China. Due to the insufficient alloy hardness of the clamp ports, the slot deviation often occurs, which leads to inaccurate pin pressure. Due to insufficient pressure applied to RJ45 metal reeds, the network cable and Metal Reed may become loose.
8. Other faults
During normal maintenance, we use network management software to check whether the connection between the network cable and the port is normal, but sometimes the network management sees that the port network is connected, in fact, it may be a virtual connection formed by poor electrical characteristics of the network cable.
For example, if a contact is interrupted, you can view the switch port through the network management system and find that the network connection is not good. If you remotely call the personnel on duty, you can find that the device is still disconnected. disable/enable the port) operation.
The next day, another interruption occurred. The network administrator can see that the port network is connected. Considering the previous day's related operations, he performed the disable/enable operation on the port again. Then, he looked at the port and found that the network cable had not been connected. Normal after changing the network cable.
To deal with these faults, we need to maintain the accumulation of daily experience. In the physical connection equipment of data communication, we do not pay much attention to the network cable, especially for a network cable that looks bright, sometimes a small network cable can cause a large communication fault.