Summary of 10 common fiber media converter failure problems and solutions

Time : Jul. 19, 2022    View : 72

Optical fiber media converters are generally used in actual network environments that cannot be covered by Ethernet cables and must use optical fibers to extend the transmission distance. They are usually positioned at the access layer of broadband metropolitan area networks and are widely used in various monitoring and security projects. However, we will inevitably encounter some failure problems in the process of using optical fiber media converters, so how should we solve the problems after encountering them.

 

        Common faults and solutions of optical fiber media converters

 

  1. When connecting the RJ45 port of the media converterwith other devices, what kind of connection is used?

        Reason: The RJ45 port of the media converter is connected to the PC network card (DTE data terminal equipment) using a cross twisted pair cable, and the HUB or SWITCH (DCE data communication equipment) using a parallel cable.

 

  1. Why is the TxLink light off?

        Reasons: a. Wrong twisted pair connection; b. Poor contact between the twisted pair crystal head and the device, or the quality of the twisted pair itself; c. The device is not properly connected.

 

  1. What is the reason for the TxLink light not flashing but always on after the optical fiber is connected normally?

        Reasons: a. The fault is generally caused by the transmission distance being too long; b. The compatibility problem with the network card (connecting with the PC).

 

  1. What is the reason why the Fxlink light does not light up?

        Reasons: a. The optical fiber cable is wrongly connected, and the correct connection method is TX-RX, RX-TX or the optical fiber mode is wrong; b. The transmission distance is too long or the intermediate loss is too large, which exceeds the nominal loss of the product. The solution is: : Take measures to reduce the intermediate loss or replace it with a media converter with a longer transmission distance; c. The operating temperature of the fiber optic media converter is too high.

 

  1. What is the reason why the Fxlink light does not flash but is always on after the optical fiber is connected normally?

        Reason: This fault is generally caused by the transmission distance being too long or the intermediate loss being too large, which exceeds the nominal loss of the product. The solution is to minimize the intermediate loss or replace it with a media converter with a longer transmission distance.

 

  1. What should I do if all five lights are on or the indicator is normal but cannot transmit?

        Reason: Generally, turn off the power and restart it to return to normal.

 

  1. What is the ambient temperature of the media converter?

        Reason: The optical fiber module is greatly affected by the ambient temperature. Although it has a built-in automatic gain circuit, after the temperature exceeds a certain range, the transmitted optical power of the optical module is affected and decreased, thereby weakening the quality of the optical network signal and causing packet loss. The rate rises, and even the optical link is disconnected; (generally, the operating temperature of the optical fiber module can reach 70 °C)

 

  1. What is the compatibility with external device protocols?

        Reason: 10/100M fiber optic media converters, like 10/100M switches, have certain restrictions on the frame length, generally no more than 1522B or 1536B, when the switches connected at the central office support some special protocols (such as: ISL of Ciss) However, the packet overhead increases (the packet overhead of Ciss’s ISL is 30Bytes), which exceeds the upper limit of the frame length of the fiber optic media converter and is discarded by it, reflecting the high packet loss rate or failure. Sending unit, the overhead of the general IP packet is 18 bytes, and the MTU is 1500 bytes. Now high-end communication equipment manufacturers have internal network protocols, and generally use separate packets, which will increase the overhead of IP packets. If the data is 1500 bytes , the size of the IP packet will exceed 18 and be discarded after the IP packet), so that the size of the packet transmitted on the line is satisfied with the limit of the frame length of the network device. 1522 bytes of packets are added VLANtag.

 

  1. After the chassis works normally for a period of time, why some cards cannot work normally?

        Reason: The early chassis power supply adopts relay mode. Insufficient power headroom and large line loss are the main problems. After the chassis works normally for a period of time, some cards may not work properly. When some cards are pulled out, the rest of the cards work normally. After the chassis works for a long time, the connectors are oxidized and cause large connector loss. This power drop exceeds the specification. The required range may cause abnormal behavior of the chassis card. The power switch of the chassis is now isolated and protected by high-power Schottky diodes, and the form of the connector is improved to reduce the power drop caused by the control circuit and the connector. At the same time, the power redundancy of the power supply is increased, which really makes the backup power supply convenient and safe, and makes it more suitable for the requirements of long-term uninterrupted work.

 

  1. What is the function of link alarm provided on the media converter?

       Reason: The media converter has a link alarm function (linkloss). When a fiber is dropped, it will automatically feed back to the electrical port (that is, the indicator light on the electrical port will also go off). If the switch has a network management, it will be reflected to the switch immediately. network management software.