Nine Facts About Microsoft Virtual WiFi at WLAN Book.com

September 7th, 2010

Nine Facts About Microsoft Virtual WiFi

by Zaib Kaleem

Nine Facts About Microsoft Virtual WiFi

Wireless Hosted Network is the official name of the WLAN feature supported on Windows 7 and on Windows Server 2008 R2 that allows for virtual WiFi. This feature implements two major functions – virtualization of a physical wireless adapter into more than one virtual wireless adapter and software-based wireless access point (AP) capability.

To receive the Windows 7 logo, a wireless driver must implement the wireless Hosted Network feature. This is huge…yes other operating systems like Mac OS X or Linux/Unix had Soft AP features but the number of wireless cards available was limited. A list of WiFi/wireless adapter that have received the Windows 7 logo is maintained by Microsoft here. Hardware may not have drivers for both 64 bit and 32 bit Windows 7 so best to check the list before making a purchase decision. If you are buying a new computer that ships with Windows 7 then you should be OK.

Wireless Hosted Network allows a physical wireless adapter to connect an access point (AP), while at the same time acting as a software AP allowing other wireless-capable devices to connect to it. This capability scares IT security managers. Now add a wired interface to the mix and and Internet Connection sharing (ICS) and things can get pretty interesting.

Layer 2 bridging is prohibited between the AP adapter and any other adapters in the system. This should make IT security managers feel a little better. Yes – a soft AP can be created but issuing out IP addresses from the corporate network is not possible.

If Wireless Hosted Network is running when the computer goes to sleep (standby), hibernate, or before the computer restarts, the wireless Hosted Network will be stopped. I guess this is suppose to prevent virtual access points from staying enabled by mistake. If you need this feature many third party apps like our WLAN Controller client and others virtual access point software apps can restart the soft AP.

SoftAP and ad hoc networking are mutually exclusive on the same physical adapter. This limitation makes sense..I don’t see any reason why both would be needed. I think in the past ad hoc networking was uses because an access point was not available so with virtual WiFi the need for an ad hoc station is reduced.

Wireless Hosted Network requires that all devices connected use the WPA2-PSK/AES. The end user can select the key using netsh wlan and also WiFi Protected Setup (WPS) is supported.

Internet Connection Sharing (ICS) can be used with Wireless Hosted Network. The public interface of ICS is the shared connection while the private interface is the virtual adapter hosting the SoftAP. The shared connection can be an Ethernet, wireless LAN, or wireless WAN connection. In the case of a wireless LAN connection, the public interface of ICS can be either from another wireless LAN adapter or the station virtual adapter on the same physical wireless adapter that hosts the SoftAP.

IT administrators can disable/manage the Wireless Hosted Network feature. For computers that are members of a domain, administrators can use group policy to disallow the wireless Hosted Network. Using netsh wlan commands, an administrator can enable or disable wireless Hosted Network locally on the computer.

Centrally Managed Virtual WiFi Access Point Software

Did I mention we have a Virtual Access Point software app that can be managed centrally called WLANController? :-)

WLANController Client and Dashboard

WLANController has two components, a software client that transforms Windows based computers into WiFi virtual access points and scanners and a web based dashboard that can manage multiple devices from a single graphical user interface. The WLANController Dashboard and client make the deployment and management of large WiFi networks quicker, simpler and less costly. We eliminated the need for any new hardware and software (other than our client) by using the Virtual Access Point capabilities available in Windows.

WLANController Requirements

Virtual Access Point: Windows 7 and a WiFi/wireless adapter that has received the Windows 7 logo
Virtual Scanner: Windows 7, Vista, or XP and any WiFi/wireless adapter
WLANController Dashboard: Modern web browser and Internet access