Causes of Optical Fiber failure and Solutions

End users, or any user who pays for the network connection failure, will pay attention to a major issue of cable, which is why the cable fails. Any network that uses optical fiber cables, its Optical Fiber Links are crucial to the performance of the entire network. Therefore, it is critical to ensure that the optical cable link is always in the optimal state. To help you understand the causes of Optical Fiber failure, Fluke network independently investigates and analyzes a large number of network end users and cable installer questions about the optical fiber link.

The Research was conducted independently by Martin Technical Research on the Fault Cause of the optical fiber link. The research is to assess 800 cable installers who have more than 20% of their work on cable installation. 50% of these companies use random surveys and inquiries, and 50% directly ask the end users about the cable. Finally, Fluke networks and Martin Technical Research believe that the results of this hybrid investigation can basically represent the overall situation of Optical Fiber failure.

Background information:

Installers include data communication contractors, electrical contractors, telecom contractors, independent optical cable contractors, system integrators, and network consultants. On average, each company has 15.4 Optical Fiber technicians. On average, 36% of these contractors work on optical cables. 3500 end users each organization has an average of 2.3 technical staff with optical cables, they include education, manufacturing, politics, banking, life insurance, retail chain stores, printing/publishers, research labs, and utilities. It is not surprising that 92% of end users have optical fiber trunk networks, and 28% of users have optical fiber cables to the desktop network. 38% of users who use optical fiber cables to their desktops.

Installation of optical cable links

The process of installing a high-performance Optical Cable Link includes laying optical cables, end-to-end connection of the dual-end connectors of optical cables, and connection between the two-end jumpers and network devices. When laying optical cables, do not bend them seriously. They will cause excessive losses. The network users in the survey mainly installed 62.5/125mm optical fiber cables, but the data showed a significant increase in 50/125 optical fiber cables. In addition, the most widely used interfaces are ST and SC.

The connection has a significant impact on Link Loss, and they may cause pattern interference to multimode optical cables. The connector can be sealed and installed at a pre-polished optical fiber connection, or polished at the site. When a pre-polished connector is used, the installer generally does not feel the importance of detecting the connector end face, because the connector end face is polished by the supplier in a controllable environment. For on-site polishing connectors, the installer uses a 100 or 200 times magnifiers to check the end face. When the installer is sure that the connector is properly connected, install it on the distribution frame or information point exit for subsequent loss tests. In this case, it is very important to identify the optical cable, because the installer must ensure that the sender of the optical cable must be identified as the receiver of the other side of the optical cable.

We found that all installers who can complete excellent projects have excellent tools. Research shows that 86% of installers use a magnifier to detect the end plane of the optical cable, and 80% of end users use this method.

Background information:

When a magnifier is used to detect the optical fiber connection surface, a laser security filtering level tool must be used to prevent invisible infrared rays in the working optical fiber cables from harming the eyes.

Common Causes of Optical Fiber failure during installation

The results of the survey indicate that (89% of users and contractors) The most common fault during the installation of optical cables is that the optical cable connector is not clean. Needless to say, Mr. C needs to communicate with Mr. D to solve the installation problem.

Generally, the installer uses a 100-fold magnifier to check the end face of the connector, but it cannot identify any end face cleaning and scratches. 250 times magnifiers and 400 times magnifiers check the difference between the end face is not clean. Although the whole side can not see the unclean side, but the high magnification can reveal the small unclean problem of the core of the optical fiber cable for signal transmission.

FAQs in optical cable link Fault Diagnosis

Fault Diagnosis of optical cable links occurs in the last step of the installation process. In many cases, the fault diagnosis occurs when the installed link cannot pass the loss test indicator. The fault diagnosis also occurs when the network device is installed. It is very strange that the detection of the Optical Cable End is not always carried out to ensure the performance of the optical cable. For example, only 60% of contract providers are involved in the inspection of Optical Cable interfaces. However, only 46% of network users check the optical connection surface.

At this time, the main reason for not performing the end-to-face check is that it is very troublesome to test the end-to-face of the connector at the distribution frame or information point exit, which makes the test very time-consuming. Remove the optical adapter behind the distribution frame, check the end plane, and re-connect the adapter. The average time of this process is about 10 minutes. Even so, it is hoped that the installation personnel will not accidentally touch the Optical Cable Junction to cause greater damage to the Optical Cable Junction.

The most effective way to check the optical connection surface is to use a video magnifier. Video magnifiers can be directly inserted into the distribution frame and the interface of the device. It saves a lot of time because you do not have to disassemble the adapter on the backplane of the distribution frame to check and re-connect it. Video magnifiers provide up to 400 times the amplification capability as well as various types of Optical Fiber Connector probes, including micro connectors (SFF), while it also avoids possible eye damage due to working infrared light sources. Compared with traditional methods, this method can save about 90% of the time. That is to say, the six connectors are detected in 6 minutes, and the traditional method takes 60 minutes. Verify and ensure that the cleaning of the Optical Cable End eliminates the potential problems with the maximum performance of the optical cable.

Video magnifiers can also be securely used on optical cables at work. For example, if a port of the 100BASE-FX 24-port switch has a problem, you can use a video magnifier to directly check the port cleanliness, even if the switch is started and other ports are working. In this case, you can directly find the fault and confirm the problem with the equipment supplier. As long as the power is continuously stopped, the normal operation of other ports on the switch will not be affected. In this survey, 67% of Installation Contractors encountered the problem that the optical cable ports of the equipment were not clean, and 44% of network users encountered the same problem.

Background information:

A video magnifier checks the network device port and may find a port with serious pollution. Before cleaning these ports, contact the equipment supplier to ensure that there are no warranty violations.

One interesting thing is that one connector is cleaned but the other connector is corrupted. After checking a dirty connector, the probe on the tester is not cleaned and another connector is tested again, leading to cross contamination. Therefore, it is very important to clean the probe of the tester. If an unclean test jumper is used, contamination may spread, resulting in high loss. Remember that jumpers can be contaminated by unclean connectors. Similarly, think about the number of patch cords that have been installed without cleaning or testing. For example, if you accidentally touch the end plane of the optical cable by hand, it may cause serious pollution. These Jumpers are the direct cause of many network faults. It is unknown that the installer and the network End User did not check the cleanliness of the Jumper and the device port when connecting the network device, resulting in more than 50% potential problems.

Interestingly, 90% of contractors and 80% of end users check the interface each time they install the connector. They generally use a 100 or 200 times magnifiers for inspection. 92% of contractors and 82% of end users use alcohol when cleaning the interface and adapter. Another common cleaning method is compressed air, which is used by 30% of contractors and 12% of network users. Some users use two methods at the same time. Others use wet alcohol cloth and non-linen cloth, as alcohol and compressed air may still leave residues at the end of the optical cable.

Optical Cable Testing Instrument

The most common Optical Cable Testing Instrument is the optical power loss test package (OLTS) and Optical Time-Domain Reflector (OTDR ). In addition, some users use the visual Fault Locator (VFLs) in the survey to detect the polarity, breakpoint, and large attenuation of light, such as the tight bundling of optical cables on the distribution frame. Some VFLs can generate two light sources, one stable and one oscillating, to help identify the polarity of the micro interface (SFF) optical cable. The investigation also shows that OTDRs is also used to locate connectors, weld points, and excessive bending faults. The survey shows that in many cases, users also require the OTDR curve and the OLTS (Loss Test) together to ensure that the installed optical cable is not over-bent, bad fusion, and connector. At this time, the end user not only ensures that the optical fiber application is within the limit of loss, but also has great confidence in the installation quality of the optical fiber, and is assured of the cost they have paid. Is the usage of the Optical Cable Testing Instrument.

Summary

Dust and other pollution are the main enemies of optical fiber data transmission, especially those of high-speed networks. The GB Ethernet Standard specifies that only 2.38dB is available for Optical Fiber Link Loss, which can cause serious impact if it is not clean. Simply checking the cleanliness of the connector and using a dust cover (SET) can effectively protect the connector from contamination. However, suitable test tools such as video magnifiers and OTDR can greatly shorten the time for fault diagnosis and thus shorten the time for network faults, reduce the loss caused by network interruption.

Background: 10 most effective methods to reduce Optical Fiber failure

1. Remember the intensity coefficient of the optical cable. Do not drag the optical cable or bend it over.

2. Clean the connector during installation as required by the vendor.

3. Use a video magnifier to check the cleanliness and scratches of the connector.

4. Use VFL to check the direction of the optical cable.

5. Use OLTS and OTDR to test the installed optical cable according to the standard.

6. When testing the optical cable link, use a clean patch cord and keep it clean.

7. dust cover shall be installed on all connectors.

8. Use a video magnifier to check the end face of the Jumper.

9. Consult the equipment manufacturer before cleaning the optical cable port.

10. When a fault occurs, using appropriate tools can reduce the time required for fault diagnosis and reduce user costs.