To whom it may concern, I am an IT administrator and the company has decided to add two more branch offices. In order to do that, I will be designing a replication strategy prior to DC deployment. Since the two new braches office will be directly connected to main office you can configure hub and spoke topology and configure the replication schedule as per requirement. I would also recommend in hub site to have minimum two DC for redundancy. In the event of failure if second DC does not exist irrespective of OS version AD replication will be down totally. At least in the hub site you should have additional DC if not present.
References webserver. (2014, October 16). Retrieved from www.microsoft.com: https://social.technet.microsoft.com/Forums/windowsserver/en-US/9088ae7d-4f5e-4581-81f4-2b0f92da7a53/ad-design-replication-scenario
References: webserver. (2014, October 16). Retrieved from www.microsoft.com: https://social.technet.microsoft.com/Forums/windowsserver/en-US/9088ae7d-4f5e-4581-81f4-2b0f92da7a53/ad-design-replication-scenario