Each calendar client (including Oracle Connector for Outlook, Oracle Calendar Desktop Clients, Oracle Calendar Web Client, Oracle Calendar Sync, Oracle Mobile Data Sync, Calendar SDK and Web Services) connects to the calendar engine to get a session process or thread. The client sessions read from the calendar database, access to which is controlled by the lock manager. Any requests for data on remote calendar databases are managed by the Corporate Wide Services daemon which also manages communications with the Applications tier (including Oracle Mail, Mobile Collaboration and the Real-Time Collaboration Web Conferencing). The SNC daemon controls access to the directory server.