How to quickly determine the cause of optical fiber failure

1. Power light is not lit

Power failure

2. Link light is not bright

The failure may be as follows:

A check if the fiber line is out of circuit

b Check if the optical fiber line loss is too large, exceeding the equipment receiving range

C Check whether the fiber interface is connected correctly, the local detx is connected with the remote Rx, and the distance TX is connected with the local RX.

D Check that the fibre connector is properly plugged 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.

3. The circuit link light is not bright

The failure may be as follows:

A) check whether the network cable is out of circuit

b Check the connection type matching: network card and router and other devices using the crossover line,

Switches, hubs and other devices using straight lines.

c) Check if the device transfer rate matches

4. The network loses the packet to be serious

Possible failures are as follows:

1 The transceiver's electrical port and network device interface, or both ends of the device interface duplex mode mismatch.

2 Twisted-pair cable and RJ-45 head have problems, to detect

3 Fiber connection problem, jumper is alignment device interface, tail fiber and jumper and coupler type match etc.

5. Optical transceiver Connection After the two ends can not communicate

1 fiber connected to the reverse, TX and RX-Connected fiber swap

2 RJ45 interface and external device connection is incorrect (pay attention to straight and stranded)

Fiber interface (ceramic core) does not match, this fault is mainly reflected in the 100M with photoelectric mutual control function of the transceiver, such as APC core of the tail fiber to the PC to plug in the transceiver will not be normal communication, but the photoelectric transceiver has no impact.

6. Time-pass time-breaking phenomenon

1 may be the light path attenuation is too large, at this time can be used to measure the optical power of the receiving end of the light power, if in the vicinity of the receiving sensitivity, 1-2db range can be basically judged as a light path fault

2 may be connected to the transceiver switch failure, at this point switch to PC, that is, two transceivers directly connected to the PC, both ends of the ping, such as not appear when the phenomenon can be basically judged as a switch fault

3 may be a transceiver failure, at this point you can connect the transceiver at both ends of the PC (not through the switch), the two sides to ping no problem, from one end to the other end of the transmission of a larger file (100M) above, observe its speed, such as slow (200M below the file transmission for more than 15 minutes), Can be basically judged as a transceiver failure.

7. Communication for some time after the crash, that is, can not communicate, back to normal after the restart

This behavior is generally caused by the switch, the switch will be all received data for CRC error detection and length check, check out the wrong package will be discarded, the correct package will be forwarded out. However, some of the errors in this process are not detected in CRC error detection and length checking. Such packages will not be sent out or discarded during forwarding, they will accumulate in dynamic cache (buffer) and can never be sent out until the buffer is filled with Will cause the switch to panic. Because at this point the transceiver or the reset switch can make the communication back to normal, so users will usually consider the problem of the transceiver.

8. Transceiver Test method

If you find a problem with the transceiver connection, test it in the following ways to isolate the cause of the failure

A) Near-end test:

Both ends of the computer to ping, if you can ping the words to prove that the fiber-optic transceiver is not a problem. If the near-end test can not communicate can be judged as a fiber optic transceiver failure.

b) Remote testing:

Both ends of the computer to ping, such as the ping does not rule must check the optical path connection is normal and fiber transceiver transmitter and receiver power is within the allowable range. If you can ping general rules to prove that the light path connection normal. The fault problem can be judged on the switch.

c) Remote testing to determine the point of failure:

First one end of the switch, the two sides to ping, if no fault can be judged as another switch fault.