Enterprise Wireless SolutionsBy David Strom | Posted 2008-03-31 Email Print
10 questions to ask before your next wireless deployment.
6. How will the wireless management software work with my wired network management tools?
If you have a wired infrastructure management system that you don’t want to replace, you need to find out how the wireless management software will interact with this system, if at all. Do your network monitoring staffs have to run two separate consoles to keep track of both infrastructures? Cisco’s MARS, for example, is still a year or so away from a fully integrated solution, although the company has begun to pull wireless tools into the product, including the ability to accept security alarms from their access points.
Another strategy is to see what wireless features are available in your existing network management tool from CA, Hewlett-Packard or IBM. Aruba’s management software—bolstered with technology Aruba acquired when it bought AirWave Wireless in January—also works with non-Aruba equipment, which is handy if you’re going to have a mixture of wireless suppliers.
7. Do I need a single wireless vendor?
Sometimes not. The latest wireless installation for Carnegie Mellon University has two suppliers, Aruba and Xirrus. Aruba is used on the majority of the campus, with Xirrus supplying wireless coverage in the dormitories and lecture halls where population density is higher. The IT staff picked the two vendors as an experiment in interoperability and also as a way to examine the benefits of both solutions.
8. Am I replacing existing 802.11 a/b/g networks or installing a new 802.11n network?
Understanding your 802.11n strategy and deciding how soon you want to implement it are key factors in determining which products to buy. The 802.11n networks are compelling because their performance is a step up from the older a/b/g networks.
Some of the earliest 802.11n adopters have been shipping their products for months, while others have just begun delivering gear that incorporates improved second-generation 802.11n chipsets. (See “Enterprise Wireless Solutions,” above.)
Part of understanding 802.11n strategies is taking stock of your existing wireless infrastructure and determining what you plan to keep versus what you’ll replace. You also need to understand which applications will benefit most from 802.11n’s increased throughput.
That said, vendors point out that the cost of 802.11n has dropped recently, reducing any price premium over the older a/b/g networks. And since 802.11n is backward-compatible with the older networks, it often makes the most sense for new deployments.
“Almost all the vendors have announced their 802.11n products, and some are shipping now,” says Mathias. “The testing that I have done says they are ready for prime time. It’s silly to be deploying 802.11g when you have four times the performance at twice the price [with 802.11n], and the pricing is very negotiable at that.”
However, if you don’t want 802.11n now, take a look at those vendors that offer in-place radio upgrades of their older products to make the migration easier and cheaper down the road.
9. How will I connect the access points, and where will they be located?
The hard part of providing a total wireless solution is the wiring: You’ll still need to cable up your access points and make sure that you can provide power to them in the best locations. “It is amazing how much wire a typical wireless network actually requires,” says Mathias. Getting this installed isn’t always easy, but several vendors—including Mobile Access, LGC and others—offer unified wiring for multiple wireless networks, including cellular and paging in addition to Wi-Fi.
10. What is the best wireless architecture for my needs?
Finally, when you have all your answers, consider the fact that each vendor has its own wireless controller architecture and there are implications for each method.
Meru puts all of its APs on the same channel and simplifies roaming by using controllers rather than individual clients for the handoffs between APs. Xirrus bulks up their APs with up to 48 radios each, which makes for less cabling and switch infrastructure. Aruba goes in the opposite direction, having an AP that is so light and small you can hang it anywhere. Aerohive doesn’t use controllers at all, which can make capacity planning easier. Trapeze uses controllers, but adds traffic management to improve performance and efficiency.
A welcome turn of events is that “the architectures are getting more flexible,” says Mathias. Notable in this respect is Aruba, which can operate as fully centralized management, distribute its management and do remote switching (like Trapeze and Meru), or do split tunneling and route traffic to the appropriate destination for improved performance.
This is certainly the wave of the future, as larger and more complex wireless installations require additional flexibility.