The session, presentation, and application layers comprise the upper layers of the ISO/OSI model. The upper layers depend on the lower layers: transport, network, data-link, and physical to handle low-level communication. The session layer manages high-level connections, called sessions. The presentation layer formats data received from the application layer before passing it to the layers. Applications that include a user interface operate at the application layer.
Windows Sockets (Winsock) operates at the session layer interface to the transport layer. Winsock, an interface between applications and the transport protocol, works as a conduit for data I/O. For more information on Winsock, see Windows Sockets.
The Microsoft Windows CE Internet API (WinInet), is an API used for Internet client application development. WinInet uses Winsock internally. The WinInet.dll module exports WinInet functions used to develop Internet applications, such as Web browsers and File Transfer Protocol (FTP) applications. For more information on WinInet, see Internet Connections.
Remote Access Service (RAS) operates in the upper layers of the ISO/OSI model. RAS is an application used to access network resources from a remote location. For more information on RAS, see Remote Access Service.
A Windows CE–based application can use Windows Networking functions to establish and terminate network connections and to retrieve current configuration data for the Microsoft Network. Access to this data is made possible by way of the Windows CE Networking API (WNet). WNet communicates through the Common Internet File System (CIFS) redirector to the remote host. A CIFS redirector is a module through which one computer accesses another. For more information on WNet, see Windows Networking.