By Staff writers, PC Authority

Windows XP’s networking capabilities have never been a particular cause for complaint among users — at least not since the release of Service Pack 2 and its improved wireless integration — but that hasn’t stopped Microsoft going back to the drawing board. The IP stack — the code implementing the many layered sets of standardised protocols which allow TCP/IP networking — has, according to Microsoft, been rewritten from the ground up and has now been nattily dubbed the Next Generation TCP/IP Stack.

The key inclusion is IPv6 support, but there are quite a number of performance enhancements that should make a genuine difference to network-connection stability and performance. For maximum throughput, the new stack implements Receive Window Auto Tuning. The concept behind this is less complex than it sounds. A device transmitting on the network can only send a certain amount of data before it has to stop and wait for the receiving device to send an acknowledgement; under XP this Receive Window is fixed. Under Vista it varies dynamically according to network conditions to maximise throughput.

On the wireless performance front, the Next Generation Stack implements a number of recently developed IETF (Internet Engineering Task Force)-approved algorithms for enhancing stability and reliability, enabling faster recovery from a number of common problems that occur with noisy and unreliable wireless connections. When it comes to the practical business of setting up a wireless network connection, the separate Wireless Networks configuration panel has disappeared and been subsumed into the Connect to a Network wizard dialog, which displays both wired and wireless connections without making a distinction between them. This makes for a less bitty approach to network setup.

Once you’ve set up your new connection, Microsoft has attempted to relieve the pain of hunting for network drives and settings scattered across a dozen different locations with the Network and Sharing Center. The previously frustrating business of browsing all computers on the local network has been solved: you can now simply click View Computers and Devices for an overview of the network unencumbered by labyrinthine workgroup navigation. You can also get the system to attempt to build a topographical map of your local connection surroundings, which looks impressive although we’re not yet convinced how useful it will be for diagnosing or configuring networks in the real world.

Much attention has been paid to auto-discovery and configuration of devices, such as routers. Two new systems, called Simple Config and LLTD (link layer topology discovery) allow, for instance, for configuration of a wireless router without having to dig into the Web-based interface of the router itself. The caveat is that devices need to implement the system in their own firmware: no production devices currently do. When devices with the appropriate firmware do appear, the process should be akin to setting up a Bluetooth connection, where pairing up the devices initially involves entering a device PIN — probably printed on a label somewhere on the device — for identification.

Sync Center
In an attempt to resolve the thorny problem of how to keep your various devices both up-to-date with each other and what to do when your laptop is offline, Vista now has the Sync Center. This effectively replaces Microsoft ActiveSync, the separate download which has handled PDA and mobile synching in XP. Sync Center amalgamates offline network file caching, synching PDAs, mobile phones and MP3 players (although the latter is still primarily handled by Windows Media Player). It usefully keeps a list of current sync conflicts (such as two people working on the same document simultaneously) so you’re not forced to decide what you want to do the instant you reconnect to the network. As with ActiveSync, devices need to have Sync Center drivers to work with it.

Behind the scenes, developers can take advantage of a new API (application programming interface) called the Network Awareness API. This keeps track of the state of the system’s connections, be they wired or wireless. An application can interrogate the OS via the Network Awareness API and get an up-to-date list of the available network connections. Not only that, an application can register itself to receive events from the API and be actively informed of a change in network status. This means that properly programmed network applications can respond to a dropped connection rather than simply hanging if they were in the middle of a network transfer. The caveat, of course, is that it doesn’t magically make programs better behaved — application programmers need to go to the extra effort of programming to the API to see the benefit.