I make the assumption that you are integrating by developing a plugin, not by developing a Driver Framework based device driver that would enable you to add the device like you do with regular camera devices.
By doing a plugin that enables the Smart Client to show, control and handle data from the Video Door Phone device, you will have a working solution. It is purely up to the plugin to understand how to get authorized on the device.
- You can do a login dialog in the plugin.
- You can use a SettingsPanelPlugin which will show up in the Settings dialog.
- You can use a PropertiesUserControl which will show up on the left hand menu when in Setup mode.
There is an alternative way, perhaps better..
The data/credentials to login could be configured for XProtect globally and I envision you could do this by developing a Management Client plugin that will allow the administrator user to configure credential for the device(s).
How to store data in the Management Client and use it in the Smart Client is shown in the Property sample.
A larger more specialized sample that shows how something is setup in the Management Client and used in the Smart Client is the Server Side Carousel sample.