I am working for a small voice company. We are going to upgrade the voice setup to the latest one. Right now we are using Call Manager 5.0, unity 5.0 and IPCC 4.0 express. We will be moving to version 8 with exchange server 2010. There is a company that is there who is going to install the voice gear for us.
Can any one please tell me
1. What are the benefits of moving to the latest version?
2. What can be the problems/risk that are there in the process?
3. Some risk/problems after the installation?
4. What critical things I need to know prior to the upgrade?