When the network operates normally, the clock synchronization path is interrupted and the clock protection switching fails. As a result, a large number of pointer justifications occur on the related Nes.
If the clock protection switching is failed may cause pointer justifications and service interruptions.
Possible Causes
lCause 1: The fibers connections on the board are incorrect.
Cause 2: The configuration of the clock tracing mode of the NE is incorrect.
Cause 3: The configuration of the clock protection switching protocol of the entire network
is incorrect.
Cause 4: The configuration of the external clock source of the NE is incorrect.
Cause 5: The hardware is faulty.
Cause 6: The extended synchronization status message (SSM) protocol is disabled or the
clock ID of the clock source is absent.
How to Troubleshoot for SDH Clock
Step 1 Cause 1: The fibers connections on the board are incorrect. As a result, the protection switching fails.
1. See the protection principles to check whether the fibers connections at the faulty point are correct.
If the fibers connections are incorrect, then re-connect the fibers. Check whether the
services are restored. If the services are not restored, check whether the fault is due to other causes.
If the fibers connections are correct, then check whether the fault is due to other
causes.
Step 2 Cause 2: The configuration of the clock tracing mode of the NE is incorrect. As a result, the protection switching fails.
See the protection principles to check whether the clock tracing mode of the NE is correct.
If the configuration of the clock tracing mode of the NE is incorrect, then change the tracing mode of the clocks on the entire network. Check whether the services are restored.
If The configuration of the clock tracing mode of the NE is correct, then check whether the fault is due to other causes.
Step 3 Cause 3: The configuration of the clock protection switching protocol of the entire network is incorrect. As a result, the protection switching fails.
1. Check whether the related NEs are added to the clock protection subnets.
If certain NEs have not been added to the clock protection subnets, then add these NEs to the corresponding clock protection subnets. Check whether the
services recover. If the services do not recover, proceed to the next step.
If all NEs have been added to the clock protection subnets, then proceed to the next step.
2. Check whether the clock protection switching protocol of related NEs is enabled.
If the clock protection switching protocol of certain NEs has not been enabled, Then enable the clock protection switching protocol of related NEs. Check whether the
services are restored. If the services are not restored, check whether the fault is due to other causes.
If the clock protection switching protocol of the entire network has been enabled, then check whether the fault is due to other causes.
Step 4 Cause 4: The configuration of the external clock source of the NE is incorrect. As a result, the protection switching fails.
1.Check whether the external clock source outputs clock signals.
If tThe external clock source does not output clock signals, then change the external clock source to make sure that the output of the clock signals is normal. Check whether the services recover. If the services do not recover, proceed to the next step.
If the external clock source outputs clock signals, then proceed to the next step.
2. Check whether the external clock source carries the SSMB information.
If the external clock source does not carry the SSMB information set the SSMB information manually. Then check whether the services recover.If the services do not recover, proceed to the next step.
If the external clock source carries the SSMB information, then proceed to the next step.
3. Check whether the external clock source is configured with the s1 byte correctly.
If the external clock source is not configured with the s1 byte correctly, then re-configure the s1 byte. Check whether the services are restored. If the services are not restored, check whether the fault is due to other causes.
If the external clock source is configured with the s1 byte correctly, then check whether the fault is due to other causes.
Step 5 Cause 5: The hardware is faulty. As a result, the protection switching fails.
1. Check the working state of the board.
2. Replace the faulty board.
3. Check whether the services are restored. If the services are not restored, check whether the fault is due to other causes.
Step 6 Cause 6: The extended SSM protocol is disabled or the clock ID of the clock source is absent.
1.Check whether the extended SSM protocol is enabled.
If the extended SSM protocol is disabled or the clock ID of the clock source is absent, then enable the SSM protocol and set the clock ID of the clock source. Check whether the services are restored. If not, check whether the fault is due to other causes.
If the extended SSM protocol is enabled or the clock ID of the clock source is specified, then check whether the services are restored. If not, check whether the fault is due to other causes.
—-End
Related Information
In the case of
Huawei OSN clock protection, the direction of each NE clock source must match the fibers connections. That is, the eastbound/westbound fibers must be connected correctly. When the clock protection fails, check whether the fiber connections of each NE on the entire network match the settings of the clock source.
Telephone: 852-30623083
