A defining feature of UPnP is that each associated device must have an IP address and control software. In addition, a device in the network can only offer access to data if it acts as a UPnP server with an active UPnP function or software. The control software enables cross-device UPnP communication and data transfer via TCP, HTTP, or DLNA protocols. Since not every device has pre-installed control software, it may be necessary to install appropriate apps on the smartphone that can access UPnP servers and load media from a PC or network hard drive.
To set up a Windows computer as a UPnP server, it is also necessary to install control software such as Universal Media Server. Meanwhile, Windows Media Player also has the function to make the computer a UPnP server. As a UPnP server, the device enables access to files from the PC from other end devices, e.g. via the VLC Media Player on smartphones or certain smart TVs. UPnP also ensures that associated USB devices and hard drives are automatically detected when you plug them into a device.