Hi,
As per the doc:
http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/voice/cube/configuration/cube-book/voi-virtual-cube.html#concept_DE8E0CE19B634390853EDDF581AF60B4
Virtual CUBE supports most of the features available in CUBE. Any feature that manages the media plane is not expected to work in the Cisco CSR 1000V router. The following features are not supported in virtual CUBE: