For full DR switchover, you must shutdown the Communication Manager in Data Center 1 so that the ESS in Data Center 2 can come into operation. The phone sets and gateways re-register with the ESS. Once the registration is complete, the agents can start handling voice contacts that are routed through Avaya Aura® Call Center Elite while Avaya Oceana® and Avaya Analytics™ are switched over to the DR site

For partial DR switchovers, you do not have to shut down the Communication Manager in Data Center 1 if the Avaya Aura® applications are fully functional.