Domain topology recommendations

If you plan on hosting Exchange mailboxes in the branch office you will require the following...

- Domain Controller
- Global Catalog
- Exchange Server (MBX, CAS, HT roles)
- DNS

If you use 2012 server in the branch site you will be required to do a Forest/Domain prep so that your 2008R2 DC can communicate. You do not have to raise the functionality but required to do a forest/domain prep.

I would also recommend that if you are hosting Exchange in this branch office you will want to have 2 DC's in there for site resiliency as the users will not be able to retrieve mail if your DC goes down at the site.

File Sharing or admin/security does not require a DC to be in the same site as it can look to another site for authentication.

One other thing to take into consideration is that if you upgrade your DC in your branch site you will also require USER CAL's for all of the users that will be authenticating to the DC. This is something that you will want to take into consideration as it is an extra cost factor.

Forest/Domain Prep for 2012 - http://social.technet.microsoft.com/wiki/contents/articles/13422.manual-schema-upgrade-for-windows-server-2012windows-server-2012-r2.aspx

Will.

Most email to/from the branch office is to/from the main office so would probably have single Exchange server in main office and have the branch office users connect to it. There are only ten users and in cached mode I thin this is quite acceptable.

There would be a fileserver at the branch office but is a DC necessary if we have a single domain?

Am I better having two domains or a single domain?

Thanks.

Also I would have to have windows update server at the branch office.

Seems like simple is best then. Any disadvantages to keeping it single domain?