vCloud resource requests and approval

Dear Folks,

Please bear if this is a noob question. But I'm new to vCloud Director. I was going through all the official documentation for deploying and managing VMware vCloud director. But no where I found topic on User requesting additional resources through web portal and its approval process. Does this requires any integration or possible only with vCloud director itself?

Please help me clarifying the same.

Thanks,

Hari.