OK ill get right into it... We have two separate forests each with one domain. One Forest functional level is 2012 R2 the other 08 R2. We each have our own exchange 2010 environments that have a federation trust. There is a two way forest trusts between us. We are in the process of upgrading our phone systems and want the shoretel system to be able to integrate into each others GAL and we are being told by our phone system vendor that we will need to all be under the same forest to do this. This process is new to us and need a little direction. Is it worth bringing in a consultant to assist with the migration. Any insight or real world experiences are greatly appropriated.