Your network contains an internal network and a perimeter network.
The perimeter network contains a server named Server1 that runs Windows Server 2008 R2.
Server1 is a member of a workgroup.
You plan to configure Server1 as a Lync Server 2010 Edge Server.
You need to prepare Server1 for the planned configuration.
What should you do on Server1?

A.
Disable IPv6.

B.
Modify the primary DNS suffix.

C.
Install the Web Server (HS) role.

D.
Set the Startup type of the Windows Audio service to Automatic.

Explanation:
http://blogs.technet.com/b/dodeitte/archive/2010/10/16/issue-when-installing-lync-server-2010-edge-server-with-computer-name.aspx