Telecom Italia is the leading provider of mobile phone services in Italy. Because of the critical nature of the mobile voice, text and data services it provides, Telecom Italia utilizes a pair of HPE NonStop servers located in different geographical areas and running in an active/active configuration. In this way, both servers can be used concurrently to handle customer calls and provide mobile services, but if one server becomes unavailable, the other server can take over and maintain customer service without interruption (continuous availability). This configuration also allows for one node to be taken out of service to perform planned maintenance, without the loss of mobile service to customers. None of these actions would be possible without the use of Shadowbase bi-directional data replication software, which is used to keep the databases of the two servers synchronized (consistent and correct).