The licensing programs have not changed since 7.1(5) / 8.0(2). This is to say that there are User Connect Licensing or Unified Workspace Licensing. The table above shows UCL licenses. What the user is entitled to use remains the same. The only difference is that CUCM and CXN 9.0 begin properly enforcing these licenses. In 8.6 and earlier the software was still tracking licenses by the legacy DLU model. The disconnect between provisioned DLUs and purchased UCL/UWL licenses allowed the customer to deviate from what they actually purchased. That will no longer be the case in 9.0.

I know that there is no direct upgrade option available but I am wondering if I can purchase above listed and then just install clean system using above quoted SKUs.

Sure. If you install a new CUCM 9.0 cluster and activate the licenses shown above in ELM you can use them.

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