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Six common faults of optical fiber transceivers, Xiaobian will teach you to solve them in three minutes

Optical fiber transceiver is an Ethernet transmission media conversion unit that interchanges short-distance twisted-pair electrical signals and long-distance optical signals. It is also called a fiber converter in many places.
Optical fiber transceivers are generally used in actual network environments that cannot be covered by Ethernet cables and must use optical fibers to extend the transmission distance, and are usually located in the access layer applications of broadband metropolitan area networks; such as: high-definition video image transmission for monitoring and security engineering; It also plays a huge role in helping connect the last mile of fiber to the metro and beyond.
Optical fiber transceivers will encounter various problems during use. Today, I will share with you the common faults and solutions of optical fiber transceivers.
1. The Link light is off
(1) Check whether the optical fiber line is broken;
(2) Check whether the loss of the optical fiber line is too large and exceeds the receiving range of the equipment;
(3) Check whether the optical fiber interface is connected correctly, the local TX is connected to the remote RX, and the remote TX is connected to the local RX
(4) Check whether the optical fiber connector is well inserted into the device interface, whether the jumper type matches the device interface, whether the device type matches the optical fiber, and whether the device transmission length matches the distance.
2. The circuit Link light is off
(1), check whether the network cable is open circuit;
(2) Check whether the connection type matches: the network card and routers and other devices use crossover cables, and switches, hubs and other devices use straight-through cables;
(3) Check whether the transmission rate of the device matches.
3. Serious network packet loss
(1) The electrical port of the transceiver does not match the interface of the network device, or the duplex mode of the device interface at both ends;
(2) If there is a problem with the twisted pair and the RJ-45 head, check it;
(3) Optical fiber connection problems, whether the jumper is aligned with the device interface, whether the pigtail matches the jumper and the coupler type, etc.;
(4) Whether the loss of the optical fiber line exceeds the acceptance sensitivity of the equipment.

4. After the optical fiber transceiver is connected, the two ends cannot communicate
(1) The optical fibers are reversed, and the optical fibers connected to TX and RX are reversed;
(2) The connection between the RJ45 interface and the external device is incorrect (pay attention to the straight-through and splicing) and the optical fiber interface (ceramic ferrule) does not match. This fault is mainly reflected in the 100M transceiver with optoelectronic mutual control function, such as the APC ferrule. If the pigtail is connected to the transceiver of the PC ferrule, it will not be able to communicate normally, but it will not affect the connection of the non-optical-electrical mutual control transceiver.
5. On and off phenomenon
(1) It may be that the optical path attenuation is too large. At this time, an optical power meter can be used to measure the optical power of the receiving end. If it is near the receiving sensitivity range, it can be basically judged as an optical path failure within the range of 1-2dB;
(2) It may be that the switch connected to the transceiver is faulty. At this time, replace the switch with a PC, that is, the two transceivers are directly connected to the PC, and the two ends are pinged. Fault;
(3) The transceiver may be faulty. At this time, you can connect both ends of the transceiver to the PC (not through the switch). After the two ends have no problem with PING, transfer a large file (100M) from one end to the other. Observe Its speed, such as very slow (transfer of files below 200M for more than 15 minutes), can be basically judged as a transceiver failure
6. After crashing and restarting, it will return to normal
This phenomenon is generally caused by the switch. The switch will perform CRC error detection and length check on all the received data. The packets with errors will be discarded, and the correct packets will be forwarded.
However, some erroneous packets in this process cannot be detected in CRC error detection and length verification. Such packets will not be sent or discarded during the forwarding process, and they will accumulate in the dynamic buffer. (buffer), it can never be sent out. When the buffer is full, it will cause the switch to crash. Because at this time restarting the transceiver or restarting the switch can make the communication return to normal.


Post time: Mar-17-2022