Sametime Complete small deployment = Minimum is 3 Servers Daniel Mendes de Oliveira e Silva 20.Jun.15 11:09 PM Lotus Notes Sametime Standard 9.0Linux
At the bare minimum, you will need:
Sametime System Console
Sametime Community Server (Domino)
Sametime Meetings Server
Sametime Advanced Server
Sametime Media Manager - Proxy Registrar
Sametime Media Manager - Conference Focus Manager
Sametime Media Manager - Video Manager
Sametime Media Manager - Video MCU
VMGR and VMCU are Linux only, and *cannot* be hosted on the same server/VM.
If you're planning on clustering in the future you need to take this into consideration as you will need to redeploy/reconfigure your Deployment Plans and reinstall your AV environment if you did not plan to break out components separately first.