Plug it in and it works

If a network is a neighborhood, it's not a friendly one. Devices don't talk to one another, let alone acknowledge the others exist. They require all kinds of help (from us) to settle in and start working. Wouldn't it be great if devices come into the network aware of self and surroundings, fully functional and able to communicate? It looks like that time isn't too far off, thanks in part to an architectural framework called universal plug and play (UPNP).

Developed by Microsoft and Intel in 1999, UPNP is a device discovery and control specification that eases and enhances network communications. (Think plug and play that works like you wish it did.) It allows peer-to-peer network connectivity, works as part of an existing network (wired, wireless, whatever), and uses familiar protocols - TCP/IP (Transmission Control Protocol/Internet Protocol), IP, HTTP (Hypertext Transfer Protocol) and XML (Extensible Markup Language) - to enable devices to configure themselves, obtain IP addresses, and discover and work with others.

In a UPNP world, when you add a new printer to the network, your PCs will know all about it and know how to print to it - without bothering you about the details. The protocol also gives devices a voice. Attach a new monitor and it will "tell" the other devices, "I'm a display, you can send pictures to me," or "I'm an audio device, you can send music to me," says Roxanne Gryder of Intel Labs. Even better, all this communication happens behind the scenes.

What is happening behind the scenes? On a UPNP network, some devices provide services, others act as control points. A control point could be the main PC or any device on the network. Control points query network devices for status, get a description of the device and a pointer to its IP address. To illustrate, the service a clock would provide is the time. Actions the control point might take on the clock are "get time" and "set time."

UPNP specifications are being built for all kinds of home network equipment - PCs, peripherals, DSL routers, cable modems, multimedia equipment, home control and security systems, air conditioners, thermostats, handhelds and phones. Today, Windows XP and ME are UPNP compliant, and so are residential gateways from Intel, Linksys and D-Link. The specification for the audio/visual devices is nearly finished, so we should start seeing announcements from consumer electronics vendors shortly.

Interestingly, Intel is taking the UPNP concept a step further to include devices that leave the home, too, Gryder says. Intel recently announced the availability of a software developers kit (SDK) that will allow developers to create handheld devices that can control UPNP-compliant devices inside the home remotely. With a UPNP handheld, you'll be able to do "whizzy things" like program your personal video recorder to tape a show, or to turn on the lights in the kitchen and den at dusk, she adds.

The SDK is part of the development kit for Intel Personal Internet Client Architecture, a platform for building voice- and Web-enabled wireless devices.

Next week, I'll be on the lookout for more UPNP developments at the Connections 2002 home network conference in Dallas. Stay tuned.