which domain and forest functional level is supportted for the "Active Directory Resource Pool Synchronization"?

Hi all,

I'd like to confirm which Domain/Forest functional levels of Active Directory is supported for "Active Directory Resource Pool Synchronization" in Project Server 2013.
I guess that 2003 or later is supported, but my customer required reliable sources.
I googled and searched article at TechNet, but I couldn't find.

Could anyone inform me the article about that?


Thank you in advance.
Kaori.