Satellite solutions

The company I work for has recently purchased and deployed several terrestrial satellite units. We rotate and deploy these units temporarily at our remote sites as needed. We have implemented a VPN solution and are experiencing extremely poor performance due to latency, tcp window size ect. I have done some research on this issue and it seems as if this is a major drawback to satellite transmission. I know the physical limitations (distance from the earth station and the satellite) can not be overcome but if anyone has any suggestions or can point me in the right direction it would be greatly appreciated.

Thank you