Guide to Enterprise Wireless LAN Systems
Five questions you need to ask WLAN vendors before buyingBy Craig Mathias, Network World, 10/1/07
If you're working on a RFP for the purchase of an enterprise-class wireless LAN (WLAN) system, or even just beginning to think about a deployment of more than a few access points, here are five questions to ask potential vendors:
Radio is a notoriously difficult environment. While the principles of radio transmission are not too different from those applied to wire, radio performance can vary from moment to moment. So, when you're estimating workloads and response windows, it's important to ask a vendor how they provide assurance that the solution they'll be proposing will meet your performance objectives. It's important to be as quantitative as possible on the requirements side, and then carefully examine the proposed solution. Get a guaranty of performance – that's always a requirement in RFPs I prepare, and the list of specific performance requirements gets stapled to the purchase order – perform or refund.
It's easy to specify a solution that meets only current needs. But the demands on networks only grow over time, along with the number of users and applications. It's thus critical to ask how the solution will scale to a potentially much larger size in response. For example: will more access points (APs) be required, or will a wholesale swapout of the controller be required? Can the management appliance handle multiple sites, and not just multiple controllers? Can I use wireless mesh connections to link APs if I need more capacity but don't have the time (or the budget) to install more wire?
Traffic mix can almost never be estimated accurately in advance. And, with more time-bounded traffic – especially voice, but also streaming video in some venues – becoming part of the mix, support for traffic prioritization is critical. Provisioning such is complicated, though, by the statistical variability inherent in radio communications. What does the proposed solution do to improve the reliability and quality of time-critical communications?
Sure, you can install a WLAN yourself, but it's ultimately much cheaper (especially when performance guarantees are part of the deal) to have the vendor, VAR, or integrator do it. Professional installers have seen it all, and can work around installation challenges that would otherwise tie up resources more suitable to other tasks. Similarly, get a support contract, with a guarantee of response times when critical failures occur (they won't very often, but angry users are zero fun).
Despite rapid growth, the wireless-LAN business is ferociously competitive. Get several bids; that's obvious. But go through a best-and-final bidding round with vendors that qualify in every dimension – design, solution, installation, and support. You'll be surprised how hard they'll work to win your business.
Finally, formal RFPs aren't always required, but they're always a good idea if for no other reason than they'll help organize your thoughts, clarify your objectives, and get buy-in from the guys with the money.