The emerging high-speed version of Wi-Fi, 802.11n, is a driver toward the "all wireless" enterprise. This is an assertion made regularly by wishful-thinking vendors but one that has also been verified by recent research. Indeed, the speed is there. But are all the availability, security, reliability and QoS pieces also in place that would allow Wi-Fi to usurp tried-and-true Ethernet?

In a recent Webtorials study of several hundred individuals involved in their companies’ WLAN projects, more than a third (35%) said that creating an all-wireless enterprise access network was one of the two most important business applications they foresee for 802.11n. And their willingness to deploy pre-standard 11n products doubled over last year.

Organizations have any number of mobility and cost reasons for wanting to extend their networks wirelessly as time marches on. And now that 802.11n – albeit a pre-standard 802.11n – offers Ethernet-like throughput of 150Mbps to 170Mbps in enterprise-class products, making the WLAN “the” enterprise LAN, rather than a mere network extension, becomes something enterprises can actually consider.

But let’s think beyond throughput. For example, how fast the network can run is really incidental if the network’s not operating. It’s also true that a highly available (HA) network is not particularly meaningful without the requisite security, QoS and performance. But let’s start with HA.

Redundancy and resiliency measures must be in place across several network segments to deliver the same or better HA experience that you get with Ethernet today:

1. In the RF network (over the air from the client device to the AP)
2. In the AP network infrastructure, including power backup to each AP
3. The AP-to-controller connection (in a controller-based architecture)
4. In the WLAN controller network segment (in a controller-based architecture)
5. In the relevant back-end servers, such as RADIUS

Today’s enterprise-class Wi-Fi vendors have varying and interesting strategies for ensuring HA. In forthcoming newsletters, I’ll examine how several of the enterprise vendor players distinguish themselves in meeting the HA challenge.

Joanie Wexler is an independent networking technology writer/editor in Silicon Valley.