Hello! We have 2 offices, main and branch. Each office has its own AD domain (without trusts). Users in branch office log in to their computers with accounts in local AD, and use Outlook and Communicator with accounts in main AD. Now we think about Lync in branch office, with Unified Messaging. So we should deploy Lync and Exchange in branch office. What is the best way to keep connection with main office? Users in branch office should see the present status of local users and users in main office. It could be done with federation. But what can we do with mail? Users in main office and in branch office share the same mail domain (@company.com), how it can be splitted between two Exchanges? What can you recommend in this situation? Thank you.

Hi, You need to configure exchange to share the domain name: http://technet.microsoft.com/en-us/library/bb676395.aspx What about exchange federation - don't you need free/busy information between the users as well? Leif

Hi, Leif! Thank you for the link! And in this solution users have 2 mailboxes in each Exchange with the same mail address or how does it look like? Can we deploy only Lync and connect it to Exchange in main office? Or AD domains must be the same? Or the trusts between AD domains will be enough? Or maybe we should look to scemes with resource forests?

Is it possible to use for Lync in branch office Exchange in main office with trusts between AD domains?

You can have one or more sites in your Lync Server 2010 deployment. Your deployment can also have one or more branch sites associated with a central site. A branch site is associated with exactly one central site, and the users at the branch site get most of their Lync Server functionality from the servers at the associated central site. And you can start from here.Noya Lau TechNet Community Support

I know it about Lync. I don't know is it possible to use Exchange Unified Messaging from central office for Lync in branch office if there are different ADs. Or maybe trusts will solve this problem.