I've got a vSphere Essential 4 license and would like to try the new vStorage backup API, I've installed the Veeam backup and replication software 4.0.80 and the Enterprise Mgr. on the physical backup server, see the following deployment diagram:

I could not select any ESXi01 or 02 local VMFS datastore from the Veeam apart from the local backup server directory, Do i have to redo the whole network deployment ?
I've read somewhere in this forum that by using hotadd (creating Windows Server 2003 VM + VBR 4.08) i need to purchase the Advanced license ? I thought that this is not the case with VCB v1.5 u1
Looking forward for any reply and suggestion.
Cheers.