A PPTP server is an intermediary computer that’s connected to both the routing network and private network.
The role of a PPTP server is to get PPP packets from the routing server, process this packet to get the destination computer’s name or ADDRESS, and send it through the private network.
A PPTP server receives the IP datagrams sent by a PPTP client and breaks it down into PPP packets. It decrypts these PPP packets USING the private network’s PROTOCOL, and routes them accordingly.
This PPTP server is CONFIGURED to read multiprotocol packets simply because PPP SUPPORTS multiple protocols.