Take your WLAN from thick to thin
Migration strategies to suit all sizes.
By Joanie Wexler, Network World | Network World US | Published: 16:00, 24 July 2006
You have an existing network of distributed, intelligent Wi-Fi access points and have decided that moving to a controller-based, thin-AP architecture will better suit your
management and security needs going forward. How do you make the transition?
Your strategy will depend on the size of your existing implementation, your budget, and your own ROI of moving to a centralised Wi-Fi architecture. You might choose one of the following options or some combination of them, for example:
- Convert your old APs into newer, thin APs by giving them a "brain transplant." This is possible for some older APs via programs offered by WLAN vendors, such as Aruba Wireless Networks' Aruba Certified Program and Trapeze Networks' Open Access Point Initiative (OAPI). Note: Not all thick APs are convertible. And of those that are convertible, some are not 100 percent convertible, meaning that not all functionality of the new controller-based management system becomes available with the conversion.
- Use an "attrition" approach, whereby you retain the old APs if they are still doing the job and begin introducing the centralised infrastructure, say, in a new site. Use third-party management software to manage the stand-alone and dependent AP environments during the transition.
- Leverage WLAN vendor/wireless management vendor partnerships to collapse heterogeneous management into one console, which helps you migrate to that specific WLAN vendor's centralised controller architecture. For instance, Aruba and third-party management software vendor AirWave Wireless say they have completed integration workween Aruba's controller and AirWave's server-based wireless management system. You gain the ability to use AirWave's basic Wi-Fi management and security capabilities for mixed-vendor networks and the Aruba-specific management features for its own APs from a single screen. You still buy both systems separately.
- Start over and replace your old APs with newer, thin APs and a corresponding WLAN controller - a.k.a. "rip and replace."
For some folks, the rip-and-replace strategy is viable. "You really have to look at it on a case-by-case basis. But I often advise companies that if they have [a WLAN] up and working to just keep it. It is easier to replace than to integrate," says Craig Mathias, wireless consultant at Farpoint Group.
Or you can combine approaches. For example, a Kansas school district is ripping and replacing but is also using Trapeze's OAPI to tide it over until the project can be completed.