Activate a SIP or IN address in an external platform definition for a SIS RA entity.
 The SIS RA entity to manage to is specified by the enclosing 
SISManagementTask element.
 For example:
 
 <sis-sip-management raentity="foo">
   <activateexternalplatformaddress extPlatformName="vpn" position="0"/>
 </sis-sip-management>
 
 This task invokes the 
ExternalPlatformManagementMBean.activateAddress(int) management operation.
 
Ant Parameters
 
 
     | Attribute | Description | Required | 
 
     | extPlatformName | The name of the external platform definition to update. | Yes. | 
 
     | position | The position in the current address list which contains the address to be activated. | Yes. | 
 
     | failonerror | Default failure case behaviour for this task. If set to 'false' or 'no', the build will continue when this task attempts a redundant action. | No.  Default is inherited from the enclosing SISManagementTask. |