Cisco introduced today its wireless LAN services module, an add-on to its Catalyst 6500 switch that integrates support for WLANs: Coupled with Cisco APs (wireless access points), the platform offers some of the functionality of other WLAN switch platforms but has some drawbacks. One of the most important capabilities that Cisco executives stressed during a Webcast this morning was the ability for users to roam between APs in 50 milliseconds--fast enough to support voice. The client is authenticated at the AP where traffic is sent through a secure roaming tunnel back to the Catalyst switch, which could be located anywhere in the network. As the client roams, its IP address stays the same, so voice calls, VPNs, and other applications aren't interrupted when the client associates with a new AP.

Because all traffic travels through the switch, roaming might not always happen in under 50 milliseconds. Cisco tested roaming between two APs that were located in Perth, Australia. The APs were connected to a switch that was located in Sydney, a distance away from Perth that is similar to the distance between Los Angeles and Miami. The handoff time increased to around 250 milliseconds, slow enough for an audible blip in a voice call. But applications are not dropped during that time.

Cisco also said that it is releasing an upgraded version of its wireless LAN solution engine (WLSE), Cisco's management software for APs across an enterprise. The new version not only detects rogue or unauthorized APs, but can remotely disable the switch port that the rogue is connected to. Also, with the new software, customers can set their Cisco APs to scan-only mode. Customers who may not be ready to deploy a WLAN may still want to ensure that rogue APs aren't being deployed. "Over time they will deploy a WLAN, and the same APs they use for scan-only can be used as regular APs," said Bill Rossi, general manager of Cisco's wireless unit. (Airespace, a WLAN switch developer, has a similar offering, which has the added feature of deassociate signal bombing a rogue AP to prevent clients from successfully remaining connected to it.)

The upgraded WLSE also supports instant AP deployment without having to configure the AP before adding it to the network. When the switch module recognizes that a new AP has been plugged in, it alerts the WLSE system, which sends the configuration file to the new AP. In the previous version of WLSE, the management software would monitor as well, but this newer method provides a more direct and instantaneous configuration.

The WLSE also optimizes frequency use. IT managers can set thresholds for capacity or coverage, and if the network exceeds those thresholds the engine will boost or decrease power in individual APs to optimize the environment. The WLSE also supports self-healing, so if one AP goes down, other nearby APs increase coverage and change channels to cover the open spot.

The switch module supports as many as 300 APs from a single switch and only works with Cisco APs. End users cannot roam between APs that are attached to different switches, however. Executives said that capability should be available some time in the future.

Cisco also introduced a new AP series, the Cisco 1300, that can be deployed indoor or outdoor.

Many of the capabilities of the new platform are also offered by the startup WLAN switch developers. Cisco has an advantage because it's a large, established company with a large base of Catalyst switch customers. Cisco also touted the fact that its platform can support 300 APs, a number it says is far greater than that supported by other WLAN switches.