Windows Embedded CE Implementation of PPTP (Windows Embedded CE 6.0)
1/6/2010
In the Windows Embedded CE networking architecture, the PPTP WAN miniport communicates directly with TCP/IP. After receiving a packet that is addressed to the private network from TCP/IP, PPP performs the framing and then forwards the packet to the PPTP WAN miniport. The PPTP WAN miniport encapsulates the information that is contained in the packet and then reroutes the packet back to TCP/IP. IP then attaches another header that contains the address of the PPTP server to the packet and passes the packet on to the appropriate network interface, which could be a LAN or modem connection to the PPTP server. After it receives the packet over the network, the PPTP server strips the IP header off the packet and routes the packet to the private network.
The following differences exist between the PPTP implementation for Windows Embedded CE and the PPTP implementation for Windows XP:
- The Windows Embedded CE implementation of PPTP provides a subset of the functionality provided in the Windows XP implementation of PPTP.
- By default, Windows Embedded CE only supports a single VPN connection. The OEM can set up the PPTP support of a Windows Embedded CE–based device so that more than one connection is possible.
- Windows Embedded CE does not support NetBEUI and IPX.
- The networking user interface (UI) that is supported in Windows Embedded CE differs from the network UI that is implemented in Windows XP. Windows Embedded CE provides a relatively simple UI that offers only a few options that can be set by the user. Underneath the UI, Windows Embedded CE supports a number of settings that developers can configure through the registry.