A legacy Remote Access Service (RAS) protocol developed by Microsoft for Windows for Workgroups 3.11 and Windows NT 3.1 and supported by later versions of Windows for backward compatibility.
Microsoft RAS Protocol enables legacy Windows RAS clients to dial in and connect to Windows for Workgroups or Windows NT RAS servers using the NetBEUI protocol.
Once the RAS client establishes a connection, the RAS server acts as a NetBIOS gateway so that the client can access servers on the network using NetBEUI, NetBIOS over IPX, or NetBIOS over TCP/IP.
Windows 3.1 does not support the Point-to-Point Protocol (PPP), but Windows NT 3.5 does. You need RAS Protocol only if you are connecting to a Windows NT RAS server from legacy Windows for Workgroups or Windows NT 3.1 clients.