Why Does a Software Rollback Occur at the Software Loading Stage?

The following describes the possible causes and the corresponding handling methods:
1. The DCN network is busy or unstable.
Handling method: When the rollback is completed, wait and allow the NE to enter the NORMAL state again. This takes about 10 minutes. When the NE is in NORMAL state, restart the upgrade task.
2. The system software package is loaded to multiple NEs on the same DCN link at the same time. The rollback occurs because loading the system software package times out.
Handling method: Load the system software package to the NEs according to the sequence of activation groups.
3. A patch package has been loaded to the NE(s) before the upgrade but the time for automatically committing the patch package has not been specified. By default, this patch package will be committed 24 hours after it is loaded. During the 24 hours, the NE(s) is/are in an incorrect state and the system software package cannot be loaded to the NE(s).
Handling method: Load the system software package at a time later than the time specified to commit the patch package.