November 2010 E-newsletter
Wireless Management Matures
Wireless local area networks (WLANs) have come a long way since the 1990s when the technology was expensive and standards were new.
Much of wireless networking's success is that it's more stable, fast and cost-effective today, thanks to mature standards-based equipment. But just as important, network managers now have sophisticated, yet easy-to-use management and monitoring tools at their disposal – and these tools are getting even better at troubleshooting, measuring performance and boosting quality and service levels.
“For a period of time, wireless network management for manufacturers was a must-have sideshow,” says Jim Frey, research director with Enterprise Management Associates.
“A lot of the technology needed to mature, and now it has,” he says. “Wireless access points are supported by most of the management tools and brought under the same scrutiny and control as any other network node.”
The tools, available from all the major providers of wireless networking equipment, including Aruba Networks, Cisco Systems and Meru Networks, now have features that let network managers configure, test and monitor performance of access points, as well as enforce policies and compliance across the WLAN. Air quality measurement, known as spectrum analysis, is now also becoming an integral part of a WLAN, as opposed to a separate, manual tool.
Matt Barber, network and systems manager at Morrisville State College in central New York, leverages a number of features that support the eight controllers and more than 800 access points from Meru Networks,which make up the college's wireless network. The WLAN, which serves as the college's primary computing backbone, supports about 3,500 people, many of whom are students with notebooks, smartphones, Xboxes and other mobile devices.
Barber says the management tools let him reconfigure the network as new access points are added or changes are made. He says Meru Network's E(z)RF Service Assurance Manager “talks to all the controllers and culls statistics and information,” such as how many users are on the network and how much total throughput is used.
The E(z) RF Service Assurance Manager is a new tool that has been available for about nine months. Barber says the access points can be scheduled to run tests of throughput and latency, and the data is recorded. That data is then compared with Barber's defined service levels, and reports are compiled that indicate which parts of the network performed well and which didn't. He says the tool is helping him be more proactive. “I can run tests on a schedule and come in every morning and look at the reports,” he explains.
The range that 802.11n wireless devices can cover in a home, office or outdoors
Source: Wi-Fi Alliance
Like most network pros, Philippe Hanset, network architect in the office of IT at the University of Tennessee, Knoxville, has had to carry a manual spectrum analyzer to help pinpoint interference that affects the network's bandwidth and performance. Hanset oversees the university's vast, campuswide WLAN, which consists of seven controllers and 2,100 access points, all supporting 5,000 faculty and staff and 26,000 students.
Now, thanks to a new software feature in Aruba's 802.11n access points called Spectrum Analysis Module, Hanset can turn one of the many access points in his network into a spectrum analyzer that scans the airwaves for interference. Hanset says the new feature helps pinpoint whether poor performance is caused by interference or something else.
“Suppose there's a report that there's unacceptable coverage in a dorm room,” he explains. “If we've established that the user device is not the issue, we can use the spectrum analyzer to determine whether there is interference in the room. If there is, we will go to that room for further investigation. If not, we'll reassess the problem. It helps with your troubleshooting logic.”
Hanset also uses the VisualRF tool that's part of Aruba's AirWave network management software. VisualRF automatically generates a map of what the network looks like in real-time RF measurements gathered from active wireless access points and controllers.
“We can see what kind of theoretical coverage there is in an area, and we can see if there's enough coverage planned for an area of interest,” Hanset concludes.
Look for Integrated Spectrum Analysis
Radio frequency interference in a WLAN is a fact of life. That's because WLANs operate in the unlicensed bands of the radio spectrum, and regulations require that these bands accept any interference. Most interference isn't nefarious, but it can wreak havoc on your WLAN's performance. It can reduce data throughput and range, hurt the quality of voice and video applications, and can sometimes even bring down a link.
To uncover and remedy RF interference, most network engineers rely on stand-alone spectrum analyzers that have to be carried out into the field to check for problems. But increasingly, manufacturers are integrating spectrum analysis into the access points themselves. Aruba offers this via its Spectrum Analysis Module; Cisco Systems recently announced its CleanAir product line of new access points that integrate spectrum analysis functionality; and Meru Networks offers it via its Meru Air Traffic Control and Spectrum Manager.