Overview of RAS

In the Windows CE RAS architecture, RAS communicates directly with PPP to establish a connection to a remote access server. RAS uses PPP to package IP data packets and forwards them to a server over point-to-point links. When PPP receives requests to send IP packets from TCP/IP, it passes the packet on to the AsyncMAC miniport. After receiving a packet from PPP, the AsyncMAC miniport performs the asynchronous framing, and then forwards the packet to the TAPI device by calling Microsoft® Win32® serial APIs. When it receives a packet through the network, the AsyncMAC miniport strips the asynchronous framing off the packet, checks the Cyclic Redundancy Check (CRC), and passes the packet to PPP through the NDIS layer.

In Windows CE, RAS supports only IP-based protocols. The following illustration shows the role of RAS within the Windows CE. NET communications architecture. The blue lines represent the call setup steps and the red lines represent data flow.

The RAS API enables developers to create custom remote Windows CE–based applications that can establish a remote connection, use network resources, and reconnect in the event of a communication link failure. Windows CE supports both RAS client and RAS server. For information about RAS server, see RAS Server/PPTP Server (Incoming).

See Also

Synchronous Operations | Asynchronous Operations | User Authentication Data | Handling Errors | Informational Notifications | Completion Notifications | Disconnecting a RAS Connection | Phone-Book Entries | Accessing the Internet Using a Modem | Dial-up Networking

 Last updated on Thursday, April 08, 2004

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