Информатика и выч. техника \ Мультисервисные сети

Alarm Lists. Regenerator section (B1) excessive errors. The board alarm indicator flashes once every other second. Regenerator section (B1) signal degraded

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Alarm Lists

As required in ITU-T Recommendation, the management and monitoring information of NEs are transmitted through a dedicated channel in DWDM system. OptiX BWS 320G system employs the OSC signal with the wavelength of 1510nm and the rate of 2Mbit/s for maintaining and managing the network.

When abnormal conditions occur in OptiX BWS 320G system, NEs will report a large amount of alarm messages to NM. Since each reported alarm is closely related to the corresponding fault, they are the reliable proofs for maintenance personnel to locate and clear faults in time.

This chapter contains major possible alarms in OptiX BWS 320G system, which are fully shown in the form of lists. The possible reasons and common processing methods for alarms are described briefly in the lists. During maintenance, the alarm analysis and performance data analysis are combined for troubleshooting.

B1-EXC

Item	Description
Alarm Name	B1-EXC
Name	Regenerator section (B1) excessive errors
Alarm Level	Minor
Alarm Category	Service quality alarm
Alarm Board	TWF/TWC/RWF/RWC/LWC/OCU
Alarm Indication	The board alarm indicator flashes once every other second
Alarm Reasons	(1) The attenuation of received optical signal is too large; (2) Fault occurs in the transmitting part of opposite station; (3) Fiber is not cleaned or connector is wrong; (4) Fault occurs in the receiving part of home station.
Processing Methods	(1) If OTU detects a large amount of B1 bit errors, it indicates that a large amount of bit errors are already generated in the received optical signal. Thus the fault occurs on the accessed SDH equipment or the connected fiber pigtail. (2) If OTU detects a large amount of bit errors, whether any bit error is detected in the corresponding OTU of opposite station should be checked based on signal flow. If not, optical paths should be checked one by one to see whether there exists the situation of large decrease of optical power. Compare with the optical powers of respective points under normal operation to locate the fault. (3) Compare the B1 numbers in a line of signal detected at OTU and OTU ends; if they are consistent with each other, it indicates that no bit error is generated during the signal transmission in OptiX BWS 320G system. If the B1 number detected in OTU is greater than that detected in OTU, it indicates that bit error is generated during the transmission in OptiX BWS 320G system. (4) The detecting functional block of OTU board being damaged, replace the board.
Remarks	If the problem is on optical path, a large amount of payloads will be affected simultaneously.

B1-SD

Item	Description
Alarm Name	B1-SD
Name	Regenerator section (B1) signal degraded
Alarm Level	Minor
Alarm Category	Service quality alarm
Alarm Board	TWF/TWC/RWF/RWC/LWC/OCU
Alarm Indication	The board alarm indicator flashes once every other second
Alarm Reasons	(1) The attenuation of received optical signal is too large; (2) Fault occurs in the transmitting part of opposite station; (3) Fiber is not cleaned or connector is wrong; (4) Fault occurs in the receiving part of home station.
Processing Methods	(1) If OTU detects a large amount of B1 bit errors, it indicates that a large amount of bit errors are already generated in the received optical signal. Thus the fault occurs in the accessed SDH equipment or the connected fiber pigtail. (2) If OTU detects a large amount of bit errors, whether any bit error is detected in the corresponding OTU of opposite station should be checked based on signal flow. If not, optical paths should be checked one by one to see whether there exists the condition of large decrease of optical power. Compare with the optical powers of respective points under normal operation to locate the fault. (3) Compare the B1 numbers in a line of signal detected at OTU and OTU ends; if they are consistent with each other, it indicates that no bit error is generated during the signal transmission in OptiX BWS 320G system. If the B1 number detected in OTU is greater than that detected in OTU, it indicates that bit error is generated during the transmission in OptiX BWS 320G system. The detecting functional block of OTU board being damaged, replace the board.
Remarks