Given the situation we met in SDC-2090 and SDC-2091, I think SDC needs a mechanism to support multiple versions of DM, for both onboarding and internal.

For onboarding DM, say in SDC-2090, we update the onboarding DM node type tosca.nodes.nfv.VduCp due to the latest changes in SOL001 v2.5.1, how do we deal with VNFs written in the old version of node type tosca.nodes.nfv.VduCp? 

For internal DM, say in SDC-2091,  if the community decided to have internal NSD sol001 compliant while keeping the AID for heat vnfs, this could result into 2 different version internal NSD representation. we need a mechanism to support both version.

The existing conformance level identifier SDC-TOSCA-Definitions-Version in the internal csar packages seems can not meet the requirement of these 2 cases.