The six common faults of fiber optic transceivers are all solved in three minutes

Optical fiber transceiver is an Ethernet transmission media conversion unit that exchanges short-distance twisted-pair electrical signals and long-distance optical signals. It is also called a fiber converter in many places.

Fiber optic transceivers are generally used in actual network environments where Ethernet cables cannot cover and must use optical fibers to extend the transmission distance, and are usually located at the access layer applications of broadband metropolitan area networks; such as: high-definition video image transmission for monitoring security projects; It also plays a huge role in helping to connect the last mile of fiber to the metropolitan area network and the outer network.

Fiber optic transceivers will encounter various problems in the process of use. Today we share with you the common faults and solutions of fiber optic transceivers.

1. Link light is off

(1) Check whether the optical fiber line is broken;

(2), check whether the optical fiber line loss is too large and exceeds the equipment reception range;

(3) Check whether the 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 if the network cable is broken;

(2) Check if the connection type matches: network cards and routers use cross-over 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 network device interface, 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), fiber connection problem, whether the jumper is aligned with the device interface, whether the type of the pigtail matches the jumper and the coupler, etc .;

(4) Whether the optical fiber line loss exceeds the equipment's acceptance sensitivity.

4. After the optical fiber transceiver is connected, the two ends cannot communicate

(1) The optical fiber is reversed, and the optical fibers connected to TX and RX are swapped;

(2) The RJ45 interface is not correctly connected to the external device (note the straight-through and splicing). The fiber interface (ceramic ferrule) does not match. This fault is mainly reflected in the 100M transceiver with photoelectric 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-photoelectric mutual control transceiver. 5. Time-on-time-off phenomenon

(1) The optical path may be too attenuated. At this time, the optical power of the receiving end can be measured with an optical power meter. If it is near the receiving sensitivity range, it can basically be judged as an optical path failure within the range of 1-2dB;

(2) The switch connected to the transceiver may be faulty. At this time, the switch is replaced with a PC, that is, the two transceivers are directly connected to the PC, and the two ends are paired with PING. malfunction;

(3) The transceiver may be faulty. At this time, connect the two ends of the transceiver to the PC (do not pass through the switch). After the two ends have no problem with PING, transfer a larger file (100M) from one end to the other end. Observe Its speed, if the speed is very slow (file transfer below 200M for more than 15 minutes), it can basically be judged as a transceiver failure

6. Return to normal after crash restart

This phenomenon is generally caused by the switch. The switch will perform CRC error detection and length check on all received data, and check that the wrong packet will be discarded, and the correct packet will be forwarded.

However, some packets with errors in this process cannot be detected in the CRC error detection and length check. Such packets will not be sent out or discarded during the forwarding process, and they will accumulate in the dynamic cache. (buffer), unable to send out, when the buffer is full, it will cause the switch to crash. Because restarting the transceiver or restarting the switch at this time can restore communication to normal.