Service on properly configured DSC should not be impacted by the software upgrade process.
It is recommended that you verify the status and health before and after a software upgrade for all platforms. Performing this task before the software upgrade ensures that possible problems occurring during the software upgrade are not caused by a pre-existing condition. Performing this task after the software upgrade ensures that the system software and data has been properly upgraded and the system performs as expected. For detailed information about verifying the status and health of your system, refer to Status Verification Before Upgrading the Software.
During the software upgrade process, the system cards are stopped, are upgraded to the new software, and are restarted in such an order that the traffic is not interrupted on the system (refer to Software Upgrade Process (DSC 8000), Software Upgrade Process - KVM, and Software Upgrade Process - VMware)
The software rollback to a previous software version is performed using the Express Rollback method (refer to Rollback to a Previous Software Version (DSC 8000), Software Rollback on KVM, and Software Rollback on VMware).
It is recommended that you plan a maintenance window several days ahead of the actual upgrade and notify Customer Support of the date of this upgrade (refer to Sonus Customer Support). For information about planning a maintenance window, refer to Planning the Maintenance Window for Software Upgrade.