The Nintendo Wi-Fi USB Connector is a wireless game adapter, developed by Nintendo and Buffalo Technology, which allows the Nintendo DS, Wii and 3DS users without a Wi-Fi connection or compatible Wi-Fi network to establish one via a broadband-connected PC. When inserted into the host PC's USB port, the connector functions with the Nintendo DS, Wii, DSi and 3DS, permitting the user to connect to the Internet and play Nintendo games that require a Wi-Fi connection and access various other online services. According to the official Nintendo website, the product was the best-selling Nintendo accessory to date on 15 November 2007, but was discontinued in the same month. On September 9, 2005, Nintendo announced the Nintendo Wi-Fi Network Adapter, an 802.11g wireless router/bridge which serves a similar purpose. Functionality The Nintendo Wi-Fi USB Connector is a re-branded Buffalo WLI-U2-KG54-YB (although this is often confused for the Buffalo WLI-U2-KG54-AI - the two adapters are almost identical, and only differ in that the latter features flash memory to allow for auto installation) based on the Ralink RT2570 chipset. This differentiated the Nintendo Wi-Fi USB Connector from most other Wi-Fi adapters as it could operate as a software access point (also referred to as a soft AP). Few Wi-Fi adapters, could do this under Windows at the time of the Nintendo Wi-Fi USB Connector release; Windows lacked both the software necessary to configure a soft AP and capable drivers natively supported by hardware. By bundling a soft AP compatible device with their own proprietary software, Nintendo was able to overcome the limitations of Windows and greatly simplified the otherwise complicated process of putting a supported device into soft AP mode, configuring it, and routing Internet traffic over it. And to add more information, a number of community development tools and drivers exist which expand the functionality of the Nintendo Wi-Fi USB Connector beyond its initial design. While not officially supported by Nintendo, the USB Connector can function as a standard wireless adapter by using modified Ralink or Buffalo Technology drivers and can be used to send official game demos and homebrew software to the Nintendo DS through the Wireless Multi Boot (WMB) protocol. Criticism Proprietary authentication The product uses a proprietary authentication mechanism; because of this, the Wi-Fi USB Connector works only with approved devices, which is limited to the Nintendo DS and Wii consoles. This behavior is an intentional design decision on