can someone explain more on Branch Office Integration

[BAGLIETTODAVID]

Im a bit confussed about Branch Office Integration can some advise a bit more information for me. Im new to vip PBX but have been using sipgate for 4-5 years and want to expand. I would also like to know if the free version is FREE im always unsure when someone says free. However sipgate is free and they have done me pround. So far I must say this software is VERY GOOD.

Thanks in advance
Dave

P.S. I know Branch Office Integration does not come with the free version.