Is a public facing Active Directory required for Lync Server?

Hello,

1. Is it possible to setup Lync Federation on a lync server that is a member of a non public facing AD?
2. Does Lync federation force me to give a public IP for my AD?
3. Does Lync Server need a real domain name like something.com? My local AD is setup to use AD.SERVER as the domain name. Will this work?

Thanks.

Josh!!