HDP Shell is a .NET component which acts as a URI Handler for Microsoft Windows.

When set-up, Windows activate HDP Shell to handle any request for URI Schemas whose protocol part is “HDP”.

For example, typing the following URL in Windows Run dialog:

hdp://ClickToDial/?number=045123456

Windows will automatically activate HDPShell putting the typed on its command line; HDP Shell will then use the URL command and data to generate a phone call using the CTI integration.