Optical fiber communication can be used to transmit signals because it makes good use of the role of optical fiber. The volume of optical fiber is very small, and it has good corrosion resistance. Even for long-distance routes, it can also play a good role in transmission. Nowadays, optical cable line has become the main way for people to communicate.

Internal factors: the insulation of optical fiber cable line. If its insulation performance is poor and the joint box is affected with moisture or water, the operation strength of optical cable will be greatly reduced due to stress corrosion and static fatigue. In serious cases, optical cable fracture may occur, resulting in failure.

Line joint failure is also the most likely place to cause problems, because its original optical cable structure has no protection or weakened. If it wants to work normally, it must rely on the joint box. Therefore, reducing joint failure can better ensure the smooth operation of optical fiber line.

External force factors, the first is the impact of lightning force. All network cables used in the wiring system have metal conductors. When they are struck by lightning, they will produce strong current, cause damage to optical cable equipment, and even cause casualties. External force, which is caused by its wiring environment. The optical fiber and optical cable are generally laid in the field, and the buried standard is deep below the underground layer. Therefore, it is difficult to avoid damage to the optical cable in this regard.

No matter which connection method is adopted in the construction, the coating layer of the optical fiber joint has been removed. Although the protection is enhanced, the strength and flexibility of the optical fiber at the joint are not as good as before. In addition, due to seasonal construction, large temperature difference or improper position of excessive force during exothermic melting during fiber winding, the bare fiber inside will be squeezed to form bubbles inside. During hot melting, dust and fine sand enter the hot-melt pipe. In addition, affected by the sun and rain, wind swing and vibration in the treatment process, there will be the possibility of obstacles at the joint of overhead optical cable.

The obstacles in the middle of the optical cable are mostly caused by human external forces, natural disasters and other factors. During the test, it will be found that one or more channels of the optical fiber at the same position are blocked, or several optical fibers in a bundle pipe have large loss. At this time, the approximate location of the fault can be judged according to the test distance and the maintenance diagram. If there is no total resistance due to shooting, knife cutting, rat damage and other reasons, and the obstacle point has a certain concealment, you can open the connector box closest to the obstacle point, disconnect the problematic optical fiber and test on both sides.