The Universal Plug and Play (UPnP) protocol is an improvement over the earlier "plug-and-pray" standard, which is a different technology. Devices that use UPnP announce their presence when they're attached to a network, which makes them easier to install and integrate, especially in a large environment. UPnP is a work in progress, however, and there are unresolved issues, particularly with authentication. Noel Danjou's Universal Plug and Play Tester is a free utility that lists all UPnP-compatible network devices, including Internet Gateway Devices.
This utility downloads as a small compressed file, even though it includes both 32-bit and 64-bit versions. The program is accessible immediately after extraction, without requiring a formal installation process. This makes it completely portable, so you can install it on a USB drive and use it on any PC. It's automatic, listing all UPnP-compatible devices on our test machine as soon as we opened it. The interface resembles a properties dialog, displaying a tree view of devices above a status report pane. We like the utter simplicity of its four controls: one for selecting which of 14 device types to monitor, another to disable Universal Plug and Play Tester, a Save button for saving test results as text files, and an About button that includes a link to the program's online forum for further help.
Universal Plug and Play Tester is freeware. Version 2.9 build 71.1 adds improved UAC support for recent Windows editions, including Windows 7. It's an extremely compact and totally portable yet capable application that can help make device configuration easier, and we wholeheartedly recommend it.