IAS on windows 2003...is there something similar in Windows 2012 R2

Hi All,

We are looking for a solution to replace the old IAS on Windows 2003 and have something similar on the modern Windows 2012 R2.The configuration of IAS is quite basic, just the basic policies, etc.

The IAS server is behind the Firewall which is configured to talk to IAS for allowing VPN users to get into the network.

We want to have a similar implementation on a Windows 2012 R2 box. Is there any way to implement what IAS is doing  or we must use a more complicate approach?

Thanks,