Disappointed in your Vista networking speed? Are some of your network programs not working properly? Is it getting worse by the day? Have other computers on your network slowed as well, even if they aren’t running Vista? The problem is most likely with your router, and the cause is most likely Vista.

So what’s going on? Microsoft created a new network stack for Vista, using more modern technologies than past versions of Windows. A recent Microsoft knowlegebase article discusses this issue and mentions that among these technologies, UPnP and IPv6 may have the biggest impact.

UPnP (Universal Plug and Play) is meant to simplify networking, allowing intelligent devices to use standard TCP/IP protocols to exchange information about each other. Using UPnP, Vista can automatically configure network addressing, announce its presence on a subnet, and exchange descriptions of it’s services. Vista uses UPnP much more than Windows XP, increasing the network traffic. It is this UPnP traffic that is most likely causing your decreased network performance, by overwhelming some routers and causing them to drop packets. These packets would have to be resent, further increasing the traffic the router has to deal with.

IPv6 (Internet Protocol version 6) was created to deal with the problem of our expanding desire to add devices to the internet. The older IPv4 only supports 4.3 billion addresses, where IPv6 can support 3.4×10 to the 28th power, a number far bigger than we’ll try to understand here. It also adds auto-configuration capabilities, as well as other features including some that relate to routing and security. Unfortunately this new protocol can cause problems with routers that use Simple NAT, an older technology for dealing with our limited pool of IP addresses. The two protocols are incompatible, so applications like Microsoft Windows Meeting Space that rely on IPv6 won’t work correctly on a router that instead uses the older Simple NAT.

So what can you do if you’re suffering from these issues? Most routers are upgradeable, allowing their firmware to be updated. Check with your routers manufacturer to see if an updated firmware is available (it’s a good idea to keep this as up-to-date as possible), which may better support the newer technologies used by Vista. If not, you’re probably stuck looking for a new router. No one said using Vista would be cheap!