First introduced in Windows XP, Universal Plug and Play (UPnP) promises to change a lot about the way we use computers. You're already familiar with basic Plug and Play (PnP), which enables Windows to automatically recognize and use hardware devices such as modems, printers, monitors, and more. UPnP extends the PnP concept to include network devices, allowing Windows to discover and use devices present on your network. One of the best current examples of UPnP in action is Windows's own Internet Connection Sharing (ICS) service. ICS provides UPnP discovery information, enabling UPnP clients to discover the presence of the gateway and request services from it. Hardware gateways, such as a cable or xDSL modem, could function similarly (and, in fact, UPnP-compatible gateways are now becoming available to purchase), allowing your client computers to automatically discover and take advantage of the gateway's capabilities.
A number of companies are participating in UPnP development. Read more at www.upnp.org.
Future applications of UPnP will likely eliminate the need to connect devices directly to your computer. Instead, devices will connect to your network, where they will be accessible to all networked computers. For example, a new printer could be plugged directly into your network. Client computers would immediately detect the new printer's presence, query the printer for its capabilities (whether it supports color, the paper sizes it can handle, and so forth), and set up an icon for the printer. Instantly, you could begin using the printer without any further configuration.
Traditionally, unconnected devices could use UPnP for new levels of technology integration. Your home stereo receiver, for example, could connect to your network, exposing its power, tuning, and volume controls to your client computers and enabling you to control the receiver from any desktop or laptop on your home network. Your DVD player could perform similar functions, streaming video from DVDs to any network-attached computer for a completely distributed home entertainment system. Other applications might include controllable lights, sprinklers, and other appliances. Although all devices must be connected to the network to operate, bear in mind that wireless networking, such as 802.11b or Bluetooth, are becoming less expensive and more common every day.
On a corporate network, UPnP offers better centralized management of networked devices. UPnP's protocols include authentication and security provisions, ensuring that only designated administrators can control UPnP devices. Windows Server 2003's UPnP support makes it ready to support UPnP devices as they are released; with the UPnP support also included in Windows XP, such devices will now start hitting the marketplace in force.