A Virtual Access Point (VAP) is a multiplexed representation of a single physical access point—it presents itself as multiple discrete access points. To wireless LAN clients, each virtual access point appears to be an independent physical access point, when actually only one physical access point exists. Virtual access points allow you to control wireless user access and security settings by setting up multiple custom configurations on a single physical interface. Each of these custom configurations acts as a separate (virtual) access point and can be grouped and enforced on a single internal wireless radio.
The benefits of using the VAP includes:
Radio Channel Conservation—Prevents building overlapped infrastructures by allowing a single physical access point to be used for multiple purposes to avoid channel collision problem. Multiple providers are becoming the norm within public spaces such as airports. Within an airport, for example, it might be necessary to support an FAA network, one or more airline networks, and perhaps one or more wireless ISPs. However, in the US and Europe, 2.4GHz networks can only support three usable (non-overlapping) channels, and in France and Japan only one channel is available. After the channels are utilized by existing access points, additional access points interfere with each other and reduce performance. VAPs conserve channels by allowing a single network to be used for multiple purposes.
Wireless LAN Infrastructure Optimization—Shares the same Wireless LAN infrastructure among multiple providers, rather than building an overlapping infrastructure, to lower down the capital expenditure for installation and maintenance of your WLANs.