Setting Up a Default Driver 
You use this procedure to allow more than one voice application to use a single VoiceXML gateway driver.
Choose to start the SAP NW configuration tool.
In the navigation pane, open the tree structure and navigate to the Applications node.
Choose cluster-data/Applications/sap.com/tc~voear.
In the defaultMPDriverID property field, enter the driver number identified.
Choose Set.
Choose .
Restart your AS Java server instance.
Note
You can restart your AS Java server instance using the SAP user management engine.
More information: Starting and Stopping Systems and Instances