Hello, everyone!
In this post, I would like to share with you IEEE 1588v2 Network Maintenance.
Maintenance for Ring Networks
For a ring network, as shown in the figure above, asymmetry compensation is performed from GPS1 to NE6 during deployment, and compensation tests are performed on the working and protection paths on the ring except for the sites using the TN11ST2+TN11SFIU boards to deploy IEEE 1588v2.
Working path: NE2–NE4–NE6
Protection path: NE5–NE6
Fault: When a fiber between NE4 and NE6 on the working path is broken, the IEEE 1588v2 signals will be switched to the protection path.
Take the following steps to maintain the network:
1. On the NE4–NE6 link, change the status of the IEEE 1588v2 port on NE6 from Enabled to Disabled to prevent the clock signals from being switched to the working path immediately after the fiber is repaired. This can prevent a loss of time source on a base station caused by asymmetry.
2. Repair the fiber on the NE4–NE6 link to ensure normal services.
3. Compensate for fiber asymmetry for the NE4–NE6 link. Note that this operation will trigger switching between base stations, which may cause a loss of time source on a base station. Therefore, perform this operation only when minimum services are running on the base station.
a. Connect the TimeAcc-007 or IEEE 1588v2 time tester to NE6 and check whether the current time offset is within the specified range of the NE. If the time offset is within the specified range, then NEs on the protection path are running normally. Otherwise, faults have occurred on the protection path and must be rectified.
b. If the NEs are running normally, change the IEEE 1588v2 port on NE6 on the NE4–NE6 link from Disabled to Enabled. This will enable the IEEE 1588v2 signals to travel along the NE2–NE4–NE6 path.
Ensure that the slave port on NE6 is located on this path after performing this step.
c. View and record the time offset displayed on the TimeAcc-007 or IEEE 1588v2 time tester.
d. Adjust the time by changing the asymmetry compensation value for the port based on the time offset. That is, add the time offset to or deduct the time offset from the asymmetry compensation value to correct the value. Note that asymmetry must be corrected for both NE4 and NE6 on the NE4–NE6 path. The asymmetry compensation values for the two lines are the same but one must be positive and the other negative.
e. After correcting the asymmetry compensation values view the time offset on the TimeAcc-007 or IEEE 1588v2 time tester to verify that the time offset is within the specified range.
After performing this operation, verify the NE tracing relationships. If the NE tracing relationships are correct, the faults on the ring are rectified and the asymmetry compensation is corrected successfully.
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Maintenance for Chain Networks
In the case of a chain network, if working and protection paths are configured for transmitting IEEE 1588v2 signals, maintain the network in the same way as described in the preceding section when the working path malfunctions.
When IEEE 1588v2 signals are transmitted over only one path and fiber on the path is broken, repair the fiber at the earliest opportunity and then correct the asymmetry compensation.
That's all, I hope you like it.
Thank you!
