OBEX Protocols Overview

The OBEX protocols enable synchronous and asynchronous device discovery for Windows Mobile-based devices. The asynchronous device discovery procedure uses fewer system resources than synchronous device discovery.

OBEX uses the Infrared Data Association (IrDA) protocols to transfer data for Windows Mobile-based devices. The OBEX server uses the IrOBEX 1.2 protocol to facilitate information exchange.

Note   In the context of wireless data exchange, a Windows Mobile-based device that initiates a connection to another device is a client. A device that listens for incoming connections from a client is an OBEX server.

The OBEX server acts as a protocol translator and forwards packets to the appropriate transport layer. It is implemented as Obex.dll, a service/device driver capable of running in the context of device.exe. The server supports two types of networking media: IrDA and TCP/IP.

Note   The TCP/IP transport is disabled by default because there is no generic authentication support, and default server extensions do not implement authentication on their own. Enabling the TCP/IP transport is not recommended.

Packet interpretation and request servicing is deferred to OBEX server extensions, which are supplied by original equipment manufacturers (OEMs) and independent software vendors (ISVs). The ObexInbx.dll included with Windows Mobile-based devices offers default inbox server extensions that support object pushing by using MIME types.

For more information about OBEX, see "Object Exchange Protocol" under the Windows CE documentation section of in the MSDN library.

See Also

How to: Implement Synchronous Device Discovery

How to: Implement Asynchronous Device Discovery

OBEX Server to Server Extension Pseudocode Sample

Registry Settings for OBEX Server

Server Extension to OBEX Server Pseudocode Sample

Send feedback on this topic to the authors.

© 2005 Microsoft Corporation. All rights reserved.