Routing and Remote Access Service in windows
Routing and Remote Access Service (RRAS) is a Microsoft API and server software that makes it possible to create applications to administer the routing and remote access service capabilities of the operating system, to function as a network router. Developers can also use RRAS to implement routing protocols. The RRAS server functionality follows and builds upon the Remote Access Service (RAS) in Windows NT 4.0. RRAS was introduced with Windows 2000 and offered as a download for Windows NT 4.0.
The Routing and Remote Access service in Windows Server® 2008 supports remote user or site-to-site connectivity by using virtual private network (VPN) or dial-up connections. Routing and Remote Access consists of the following components: