UPnP Wireless Routers + Vista + IGDDC (???)

To get the most out of your wireless router, get one that is certified for Windows Vista. Officially, there aren't many. You can test your router for Vista-friendly features with Microsoft's online check (IE6+ only). Luckily, my new Netgear router had updated firmware to take advantage of UPnP etc., but my old LevelOne router did not have proper UPnP functionality even though it was in the release notes for the latest firmware. UPnP is handy for opening ports when necessary for multimedia streaming. There have been security concerns about UPnP in the past, but Vista does well to separate Public vs Private networks.

Following the results of the above-linked Internet Connectivity Evaluation Tool can be tricky. You can find online documentation for disabling RWIN auto-scaling if necessary or enabling Compound TCP if your router can accept it (either using Netsh), if those defaults should be changed. However, it can be a real mystery to make your UPnP router work. It could be the Microsoft has another confusing and hard to-remember name for the technology: Internet Gateway Device Discovery and Control (IGDDC). To take advantage of IGDDC, you must have:

1. A UPnP-compatible router with UPnP enabled
2. Network Discovery turned On (be on a "Private" network)
3. Internet Connection Sharing turned On for the Wireless Network Connection
4. UPnP Device Host service set to Automatic (Delayed) (this is the default)

You might need to restart your PC or disconnect/reconnect for the changes to be active.