Internet Connectivity Evaluation Tool

Internet Connectivity Evaluation Tool - Technical Information This tool is intended to be run from a home network. Running this tool from inside a corporate firewall won't return accurate results. During testing, the tool contacts a Microsoft server and sends information about your computer ("standard computer information"). This information is only needed as part of the standard Internet protocol and generally is not personally identifiable. Standard computer information typically includes information such as your Internet Protocol (IP) address; operating system version; browser version; your hardware ID, which indicates the device manufacturer, device name, and version; and your regional and language settings. This information is stored in Web server logs temporarily as a security measure (for example, to help prevent Denial-of-Service attacks). Although it is unlikely, testing might interrupt your Internet connectivity or cause your router to stop responding. In that event, the test will notify you. To restore your Internet connectivity, you can unplug the power cable from the router and then plug it back in. The following tests evaluate several technical aspects and capabilities of your router. The results report you receive at the end of the test will describe how your router's capabilities will support specific Windows Vista features. Basic Internet Connectivity Test This test is intended to ensure that your computer has basic Internet connectivity, which is needed for the rest of the tests. This test may take up to 60 seconds to run. A result of "Supported" indicates that your computer has basic Internet connectivity. Your computer already has or had basic Internet connectivity in order to reach this Web page. Therefore, a "Not supported" result in this test could mean that you lost connectivity recently, possibly due to a router or Internet connection that stopped working or that provides connectivity only intermittently. If you ran the test over a wireless network, you might want to try again using a wired connection to eliminate the possibility of wireless interference causing failures. Also, other software or a network device (such as a firewall or proxy) might be preventing the test tool from connecting to the Internet, in which case the test results won't be accurate. Network Address Translator Type One primary function of most home Internet routers is Network Address Translation (NAT). Routers providing NAT support assign private IP addresses on the local network. NAT maps these private addresses on the inside network to a public IP address on the outside network so that computers behind the Internet router can communicate with the rest of the Internet. Since Network Address Translators can work in different ways, this test uses Microsoft servers to identify your router's NAT type. Some protocols work better through routers that act as cone-type NATs than routers that act as symmetric-type NATs. This test may take up to 60 seconds to run. Success of this test means that your Internet router or firewall acts similar to a cone NAT. This means that it helps applications which use Internet Protocol version 6 (IPv6) to connect, regardless of your ISP's IPv6 support. For example, in Windows Vista you can collaborate with others across the Internet using Windows Meeting Space. A result of "Not supported" in this test does not impact your basic Internet connectivity. One possible reason for this result may be that your computer is connecting through an Internet router that acts as a symmetric NAT (view the detailed report to determine if this is the case). Microsoft has determined that symmetric NATs can block the traffic of programs that use IPv6 tunneling over IPv4 (see Teredo Overview for details of how this works). Failure to connect using IPv6 may cause these programs to not run or to have a degraded experience. It is also possible that the servers used to determine the NAT type are temporarily unreachable, in which case running the test again later will give a more accurate result. Traffic Congestion Test Internet routers sometimes lose information that is being transferred across the Internet when they experience congestion (full router queues). This loss of information is known as packet loss. Internet protocols like the Transport Control Protocol (TCP) can use packet loss as a congestion indicator. Explicit Congestion Notification (ECN) is a mechanism that provides

routers with an alternate method of communicating network congestion. This notification effectively reduces TCP retransmissions and increases throughput. This test attempts to download a short Web document, first with ECN enabled and then again with ECN disabled. If both downloads succeed, the test passes, which indicates that your Internet router successfully allows packets through with ECN options set. This test may take up to 60 seconds to run. A result of "Supported" indicates that your router can work with this new Vista Feature to improve download speeds and increase endpoint connection reliability. Note You would need to explicitly enable ECN on Vista to take advantage of this feature. If this test gives a result of "Not supported" and ECN is enabled, Windows cannot use ECN to detect network congestion and optimize downloads. However, your basic Internet connectivity should not be affected. TCP High Performance Test Window scaling is a Transport Control Protocol (TCP) option introduced for addressing performance problems. Some Internet routers cause TCP data transfers that use window scaling to fail, particularly when there's a mismatch between the scales chosen by two computers transferring the data. This test downloads a series of Web documents of increasing length until either an incomplete download is encountered or all downloads succeed. Success indicates that your router allows Windows Vista to negotiate the best data transfer rate and help improve download speeds. This test may take up to 60 seconds to run. A result of "Supported" means that Windows Vista automatically uses window scaling to negotiate the best/largest data transfer rate and help improve download speeds. If window scaling is not supported, your router cannot take advantage of network performance improvements for large file transfers. However, your basic Internet connectivity should not be affected. UPnP Support Test Many applications need to open ports (allow incoming traffic) through an Internet router, particularly when both communicating endpoints are behind different NATs. Modern routers allow hosts to create such open ports using Universal Plug and Play (UPnP). This test ensures that the router has UPnP enabled, can support a reasonable number of open ports, and can maintain these settings. This test may take up to 180 seconds to run. A result of "Supported" means that your Internet router supports UPnP. You may enjoy enhanced experiences with programs such as Windows Live Messenger or Windows Media Player. UPnP can also help facilitate certain online multi-player games. If this test does not succeed, experiences using certain programs may be degraded. However, your basic Internet connectivity should not be affected. Multiple Simultaneous Connection States Test This test creates 80 concurrent TCP connections to external Web servers and keeps them alive over the period of two minutes by attempting continuous data download using HTTP. Passing this test indicates that your router robustly supports multiple computers or programs accessing the Internet simultaneously. This test may take up to 180 seconds to run. A result of "Supported" means that your Internet router can handle a large number of simultaneous connections. This will enable you to connect to the Internet reliably using multiple applications or multiple computers. Also, your experience with applications that use multiple network streams (like some file download/sharing programs) will be enhanced. If this test does not succeed, certain applications which use multiple network streams may run in a degraded manner, or you may have difficulties when using many Internet applications at the same time. However, basic Internet connectivity should remain unaffected.