We have two locations between which we want to have secure connection. The link between those two networks is 4Gbit/s, and the problem is that our firewalls can provide VPN with maximum throughput of 400Mbit/s.
Upgrade of the firewalls is out of questions, we bought them few months ago, and to turn off encryption is also out of questions.
We are thinking to buy 4 windows server (2008 or 2012) machines which would be placed at locations (2 at each location, one would be main and another failover), and they would be in charge of traffic encryption between those two locations. This would cost a lot less then firewalls or encrypting device that was recommended to us which can guarantee 1GBit/s(~70 000 USD).
Is this doable, and what throughput can we excpect?2008