Common problems and solutions in the installation and use of optical transceivers

- Dec 25, 2020-

Problem and solution of lumen lamp not shining after installing light module

Q1: The Optical transceiver and two pairs of multi-mode fiber jumper are used to connect Huawei Switch and Hua3 switch. The optical transceiver is not bright

A: on the premise that the equipment is working properly, we first need to eliminate the problem of the optical fiber line itself, and then check whether the state of the optical aperture is open, whether the optical fiber jumper is connected to the reverse, and whether the mode of the optical aperture is consistent, can also be directly adjusted to the light mode of operation.

network interconnection

Q2: Cisco switches are connected to Huawei switches using light modules and fiber optic jumpers, and the lights are not lit.

A: The aperture is usually optically reusable, and its default state is off. This problem can be detected by checking whether the light port is on, then checking whether the light module parameters such as wavelength, speed and transmission distance match, and then checking whether the gateway is configured and whether the VLAN is the same.

Q 3: The Optical Fiber Jumper is at one end and the S5120-28P-LI switch is at the other end.

A: The Optical Port of Hua-san S5120-28P-LI switch is not the type of photoelectricity reuse. First, we need to confirm whether the type of optical fiber jumper and optical transceiver is correct, and second, whether the optical fiber jumper is connected to the wrong side. If the problem is not resolved, you can use the display interface transceiver verbose command to view the parameters of the light module and adjust the connection according to the display.

Q4: two Huawei Light modules are connected, one of which has an indicator light on and the other one does not

A: if the optical fiber jumper corresponding to the optical transceiver receiving port is normal, and the problem is the optical fiber jumper of the transmitting port, the result is that the indicator of the local optical transceiver is on and the indicator of the optical transceiver on the opposite side is not. The solution is to switch the two end of the fiber jumper position, if the opposite end of the Light Module Indicator Light and Local Light Module Indicator Light is not on, which indicates that one of the fiber jumper problem. If the local optical transceiver can receive the optical signal of the end-to-end optical transceiver and the optical signal of the local optical transceiver can not be received on the end-to-end Optical transceiver, it must be the local optical transceiver or jumper problem.

Q 5: The Lights Don’t come on when the two light modules are connected A: the possible causes are wavelength mismatch, fiber-optic jumper connections reversed, and incompatibility of different brands or models of optical transceivers. The optical transceiver can be replaced, the connection direction of the optical fiber jumper can be adjusted, and the optical transceiver can be forced to be configured.

Q 6: This Side and the opposite side are using 10G SFP + single-mode optical transceiver, the default non-self-negotiation, the opposite side is not clear, but both sides of the indicator light is not bright.

A: First Test the optical fiber at both ends of the light-decay is in the normal range, if the optical decay is normal and then check the optical transceiver and selfnegotiation. In addition, if the two 10G SFP + light modules are not the same brand, the Speed 1000, duplex full configuration is required.

Alarm issues and solutions after Optical transceiver Installation

network expansion

Q1: An Ethernet optical transceiver configuration error caused the switch to report a LINK alert and port could not be UP

A: you can test the business configuration with a test frame to see if the switch and the transport docking port work in the same mode setting. If the switch port failure still exists, you can adjust the service to another module, and then UNPLUG The Optical transceiver to see the model and speed. If the wavelength and speed of the optical transceiver and the switch do not match, you can try to change the optical transceiver and then test, the switch port should be in the LINK state at this point.

Q2: Huawei OceanStor 9000 has been alerted to an unusual transceiver power issue for its optical transceivers

A: the reason for this is usually because the light module is not plugged in tight? At this point, you can try to re-plug the light module, and then observe the status of the network Port Indicator. If the problem persists, use the Transfer (m) command to check the length of the fiber to see if it exceeds the specified length, as well as the fiber type of the light module on the opposite end.

Q3: How Does the switch turn off the alarm on the non-huawei Custom Optical transceiver?

A: you can use the command transceiver phony-alarm-disable to turn off the nonhuawei Custom Light Module Alarm.

Q4: the warning message indicates that the optical transceiver needs to be replaced

A: you can check whether the optical transceiver’s working parameters, interface information and transceiver package are normal, and then check the optical jumper. You can also try to replace the optical transceiver and optical jumper. After the optical transceiver is replaced, you need to observe the status of the warning light.

Red light problem and solution after installing light module

Q: After the installation of the Light Module, the 10GE Port Indicator Light is red and the system has no alarm.

A: the main reason should be that the optical transceivers are not compatible. You can open the running data, view the optical transceiver manufacturer information, if not compatible, you can directly replace the optical transceiver.

Failure problem and solution of optical transceiver

Q1: The Failure of the optical transceiver resulted in the disruption of the entire MSAN service and all broadband and voice services.

A: light module failure performance is normal light receiving function, but not light or light power is not enough, when the opposite side of the normal light display online, and the opposite side of the switch light display down, resulting in the whole box business interruption. The Port of the failed optical transceiver docking can be closed on the docking switch, when the optical transceiver on IPMB receives no light, and when the backplane port is open and receives light, the system is switched to the backplane. Note: Back Light must be opened; in the switch to check light state, timely found the switch light state for down and IPMB light on the end of the online situation, this time should be IPMB light failure, timely replacement can be.

Q2: we have an anomaly in the optical transceiver docking

The reasons for this are the mismatch between the optical transceiver and the fiber jumper, the shutdown of the port, the low or high power of the transmitting light, the low or high power of the receiving light, and the mismatch between the two connected optical transceivers.

A: display interface transceiver to see if the light module under “Alarm Information” has an Alarm; display interface transceiver verbose to see the diagnostic information of the Light Module, at which point the current transmitted and received light power values are visible, and the default maximum and minimum power values. If the result is shown as follows, you can do this:

  • If the receiving power is Low (RxPower Low) : There may be no UP port or UP after the message is discarded, then need to check the transmission distance is beyond the normal range, and then check the optical transceiver, fiber jumper is damaged.

  • If the receiving power is High (RxPower High) : the reason may be that the optical transceiver is a long-distance optical transceiver, and the actual transmission distance is too short to cause the signal not attenuation, can increase the optical attenuation on the optical transceiver.

  • If send Low power (TxPower Low) : Light Module send signal is not good, resulting in port not UP or UP after the message has been discarded, and the corresponding supplier after-sales contact.

  • If the transmission power is High (TxPower High) : may be due to the failure of the local optical transceiver, resulting in the receiving power continues to be too High and burn out, must replace the optical transceiver.

Caution: After the port is inserted into the optical transceiver and the docking is successful, the warning information of sending or receiving optical power should be checked to avoid abnormal flow or optical transceiver caused by too low or too high power.

Problems and solutions of optical transceiver interfacing

Q1: The Transmitter and receiver of the optical transceiver are abnormal

Reasons: This phenomenon occurs for two reasons: The Optical transceiver’s light mouth is polluted and damaged, resulting in the loss of optical links, so that the optical fiber link is not connected; And static electricity changes the impedance between the lines.

A: check whether the optical fiber jumper is compatible with the optical transceiver: the multi-mode optical fiber jumper jacket is printed with the words 62.5/125U or

50/125u, while the single-mode optical fiber jumper jacket is printed with the words G652d or 9/125U; Self-loop check: the transmitter and receiver of the optical transceiver can be connected by jumper, if the switch is working, the switch is working properly; Port Configuration: Open the light port for communication between switches of different brands, you also need to configure the port rate and working mode to 1000Mpbs and full duplex; confirm compatibility: usually you need to write to the manufacturer, which is what we call compatibility, such as communications that are still down, please Contact Customer Service if your optical transceiver is compatible with your device; troubleshooting optical transceiver: check whether the fiber jumper is compatible with the optical transceiver. The user can view the alarm, diagnostic, and manufacturing information of the light module through the display transceiver and display transceiver diagnosis interface commands.


In addition to the operator’s own experience, the quality and performance of the switch and jumper are closely related to the problems in the use of the optical transceiver. The use of reliable and stable optical transceivers and their related products will greatly reduce the probability of failure during their use, and OPTICO not only has a complete test system and a comprehensive product line, all products are also in line with international standards, cost-effective, so choose us, is your best choice!