The WSD Port Monitor is a new printer port monitor in Windows Vista and Windows Server 2008.  This port monitor supports printing to network devices that are designed to include Web Services for Devices (WSD) technology.  Web Services for Devices allows network-connected IP-based devices to advertise their functionality and offer these services to clients by using the Web Services protocol.  WSD-based devices and clients communicate over the network using a series of SOAP (Simple Object Access Protocol) messages over UDP and HTTP(S).  WSD for Devices provides a network plug-and-play experience that is similar to installing a USB device.  Web Services for Devices also defines a security profile that may be extended to provide additional protection and authentication using device-based certificates.

The WSD Port Monitor is installed by default on Windows Vista.  On Windows Server 2008, the port monitor is installed along with the Print Services server role.  Web Services for Devices is not available for Windows XP or Windows Server 2003.  These clients can print to WSD-based devices that are shared on computers running Windows Vista or Windows Server 2008.  There are four main tasks performed by the WSD Port Monitor: