Solutions for Common Problems of the SFP Fiber Media Converter

The SFP Fiber Media Converter is generally used in the actual network environment where Ethernet cables cannot be covered and optical fibers must be used to extend the transmission distance, and are usually positioned in the access layer application of broadband metropolitan area networks; such as: high-definition video image transmission for monitoring security projects; It also played a huge role in helping to connect the last mile of fiber optic lines to the metropolitan area network and the outer network.

Q: Power light does not light up?

A: Electricity failure. Please check whether the power supply is working properly.


Q: The LOS light is not on?

A: (1) The optical cable from the computer room to the user end has been broken.

(2) The SC pigtail and the slot of the fiber optic transceiver are not inserted well or have been disconnected.


Q: The Link light does not light up?

A: (1) Check whether the optical fiber line is open;

(2) Check whether the loss of the optical fiber line is too large, which 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 properly inserted into the device interface, whether the jumper type matches the device interface, whether the device type matches the optical fiber, and whether the transmission length of the device matches the distance.


Q: The circuit Link light does not light up?

A: (1) Check whether the network cable is open.

(2) Check whether the connection type matches: use crossover cables for network cards and routers, and use straight-through cables for switches, hubs and other devices.

(3) Check whether the transmission rate of the device matches.


Q: The serious network packet loss?

A: (1) The electrical port of the transceiver and the network device interface, or the duplex mode of the device interface at both ends do not match.

(2) There is a problem with the twisted pair cable and the RJ-45 head. Check it.

(3) Optical fiber connection problem, whether the jumper is aligned with the device interface, whether the pigtail matches the jumper and the coupler type, etc.


Q: After the Fiber Media Converter is connected, the two ends cannot communicate?

A: (1) The fiber connection is reversed, and the fiber connected to TX and RX are swapped.

(2) The connection between the RJ45 interface and the external device is incorrect (pay attention to the straight-through and twisted connection).


Q: Turn on and off phenomenon?

A: (1) The attenuation of the optical path may be 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) The switch connected to the transceiver may be faulty. At this time, replace the switch with a PC, that is, the two transceivers are directly connected to the PC, and both ends are PING. If it does not appear, it can be basically judged as a switch failure.

(3) The transceiver may be faulty. At this time, you can connect both ends of the transceiver to the PC (don’t go through the switch). After both ends have no problem with PING, transfer a larger file (100M) or more from one end to the other, and observe it if the speed is very slow (files below 200M can be transferred for more than 15 minutes), it can be basically judged as a transceiver failure.


Q: The machine crashes after a period of communication, that is, it cannot communicate, and it returns to normal after restart?

A: This phenomenon is generally caused by the switch. The switch will perform CRC error detection and length check on all received data. If the error is detected, the 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. They will accumulate in the dynamic buffer, and it can never be sent out. When the buffer is full, it will cause the switch to crash. Because restarting the transceiver or the switch at this time can make the communication return to normal, so users usually think it is a problem with the transceiver.


Q: How to find the problem with the converter connection?

A: (1) Near-end test:

The computers at both ends are pinging, if it can ping, it proves that there is no problem with the optical fiber transceiver. If the near-end test fails to communicate, it can be judged that the fiber optic transceiver is faulty.

(2) Remote test:

Computers at both ends are PING, if PING fails, you must check whether the optical connection is normal and whether the transmit and receive power of the fiber optic transceiver is within the allowable range. If you can PING, it proves that the optical connection is normal. It can be judged that the fault problem lies in the switch.

(3) Remote test to determine the point of failure:

First connect one end to the switch, and PING at both ends. If there is no fault, it can be judged as the fault of the other switch.

Post time: 2021-01-20


Lomoveishiy – Finland

I needed those to connect my PC on the third floor to have internet access in that room, and ISP installed their modem on the first floor only. After dropping fiber patch cables, plugged in all cables into these media converters at both sides, and link came up instantly. Was much easier than I thought!

Raymond – USA

Great experience – units worked straight out of the box – just needed plug in cables and we were done. I also like the possibility to enable jumbo frames, while we do not have a need for this feature at the current moment it’s great to have this option.

Recent Blog

View More+

Leave Your Message