When you dial a RRAS server, the client may receive Error 629:You have been disconnected from the computer you dialed.

On the RRAS server, the Event Viewer contains:

Event ID: 20073
Source: Router
Type: Error
Description: The following error occurred in the Point to Point Protocol module on port %port%. There are no authentication protocols available for use.

The most likely cause is that the RRAS server's authentication and encryption settings are set to require Microsoft encrypted authenticaltion, yet you are using RADIUS.

Set Authentication and Encryption settings to Require encrypted authentication or Allow any authentication including clear text or set OfferMSCHAP to 1.