In a side by side migration, a new Enterprise Server is created, separate from the current production Enterprise Server. This recommended practice facilitates thorough testing and staged client updates and supports rollback, if required, by retaining the old platform.
A side by side migration carries the lowest level of risk in upgrading but may require purchasing additional hardware depending on your current configuration.
Additional licensing is not required when running a second Enterprise Server for the purposes of migration or to create a sandbox environment. To mitigate risk, consult a certified technician before configuring a second server. Once a license has been migrated, support will be provided for the latest release only. Support will not be provided for the older server with the previous release or the sandbox server.
A side by side migration is strongly recommended when upgrading an environment that currently uses voice and other media types. With a direct upgrade, Multimedia Contact Center functionality is lost while you configure your new email settings. In a side by side migration, where you install the new version on a new server, this situation is mitigated. There is only a temporary loss of functionality when you move your live data from the old system to the new system.
After restoring the configuration backup to the new server, data collection, synchronization, and voice contact control on the production PBXs begins. This ensures a minimal gap in reporting data. If the data directory is copied and the database restored outside of business hours, there is no reporting data gap.
We recommend testing your new configuration by creating a test email queue, a test chat queue, a test SMS queue, and a test agent on the new server and validating that email, chat, SMS, and open media are being correctly routed to queues and agents. Run reports to verify accuracy. Confirm that email aliases or distribution groups and URL redirects for chat have been correctly implemented.
In a side by side migration, once the new server is installed and all of the devices configured we recommend you then proceed to upgrade one client and ensure the system is functioning correctly before upgrading all other clients. If you choose to upgrade on top of your current system, the clients are automatically updated during the upgrade process.
For more information, see https://mitel.custhelp.com/app/answers/answer_view/a_id/1011100/loc/en_US.