Management challenges

Enterprise network managers report that WLANs pose the same management challenges as their wired counterparts -- multiplied by 10.

For one, disassociating network availability from a specific switch, cable or port increases the difficulty of troubleshooting performance and connectivity problems. Diagnosing poor application or client performance also remains a challenge because it is nearly impossible to recreate the exact scenario that occurred to learn the root-cause of the degradation.

"The wired net is static and each device has a history that goes a long way toward troubleshooting performance problems. A port on a switch can tell a lot about a network connection," says John Tuman, director of network services at WakeMed Health & Hospitals in the US. "There is little history to tap into with wireless, and most performance problems are reported long after the fact, both of which make it very difficult to find or reproduce the error and stop it from happening again."

Tuman upgraded from an older pre-802.11 WLAN to a controller-based WLAN from Aruba Networks in 2005. More than 800 Aruba thin access points are distributed in 14 WakeMed buildings, with nine Aruba controllers. About 350 wireless phones are linked to the "nurse call" system, which has streamlined voice communications between patients and nurses, and among nurses and physicians. Another 300 phones are used by doctors, IT staff, administrators and facilities personnel. He previously used Aruba's management platform, but now Tuman says he is looking at AirWave's suite because it offers a potential improvement over what he has now.

The AirWare purchase brought to Aruba an agnostic WLAN management application, meaning it can manage different brands of equipment, and one of even fewer that can manage different types of wireless networks including mesh and WiMAX. For Tuman, he hopes the AirWave buy will provide more granular details around coverage maps and reduce some manual tuning that still must be done on access points.

"I'd like to see more intelligence in the tools, for them to have more management savvy," he says. "The coverage maps are not gospel, they give you a coarse understanding of what the coverage is, but we still need to send someone out to verify coverage and manually tune access points."

On top of performing advanced wireless network analysis manually, network managers must still take into account myriad physical considerations such as access point location, construction and microwave oven use -- just to name a few -- to ensure their non-physical network continues to keep users connected.

"With wireless, we have to deal with outside influences causing interference and rogue access points popping up. Things not connected to our network, things in the air, cause the most performance problems and could bring the wireless net down," says Matt Barber, network analyst at Morrisville State College in New York. (See the latest in our ongoing coverage of Morrisville's pioneering 802.11n WLAN deployment.)

Barber has 720 AP320 802.11n dual radio Meru Networks access points installed, supporting about 3,300 students and 1,000 to 1,500 clients at any given time. He uses Meru's management software provided in the E(z)RF Application suite and says he'd like to see a better interface and dashboard from the vendor. He also keeps the wired network management stats provided by the Enterasys NetSight application separate because the Enterasys console couldn't give him the details he is able to see from Meru's tool.

"Keeping the wired network up is critical because it feeds all the access points. Without it, the wireless net is useless. But wired and wireless have to be managed by two completely separate tools," he explains. "I would not be able to get enough wireless-specific information, but the idea of centralization is a good thing. It helps to be able to look at my wired or wireless net from anywhere."