Network administrators overseeing large-scale wireless local area networks (LANs) have the dizzying task of keeping...
thousands of wireless LAN access points (APs) performing as quickly and reliably as their wired networks. Wireless network management tools bring scalability to an otherwise daunting job.
"The management of our wireless network, when you boil it down, is three people. It's three busy people, but not three suicidal people," said Scott Ksander, executive director of networks and security at Purdue University in West Lafayette, Ind., where more than 6,000 802.11n access points cover 265 buildings. "[Remote management solutions] are mandatory tools in our environment because we simply cannot go out and touch thousands of things. It's just not possible."
Although the 802.11n-based wireless campus enhanced student learning at Purdue, it has also highlighted the IT team's need for strategic network monitoring as it supports 10,000 users each day. Network support is available 18 hours per day and five days per week, but the department also has a "crisis team" on-call and a pre-packed "go bag" of diagnostic and repair tools for network emergencies.
"We had to develop a different tool set, and we also had to develop a different response scenario. In the wired world, if someone told us something wasn't working, if we arrived an hour later, chances were it still wasn't working," Ksander said. "With wireless, if something isn't working now … you have this mystery you have to cope with [when you arrive]."
Using a controller-based architecture is a must for effective large-scale wireless network management, said Paul DeBeasi, senior analyst at The Burton Group. DeBeasi, who defines "large-scale" networks as those with thousands of APs, also recommends investing in wireless network training and certification programs.
"Size brings problems on a much greater scale," DeBeasi said. "But if you've got more modern equipment with controller-based architecture and tools, you're maintaining the software revisions, you removed your old equipment and you've got a good network design … then your staff is not going to be running around like chickens with their heads cut off."
Get visibility and control with wireless network management tools
Ksander uses Cisco Systems for his APs and controllers but said he also relies on Cisco's Wireless Control System (WCS), network management software that helps administrators design, implement, monitor and secure WLANs. The platform uses a heat map to show AP performance and allows some remote diagnoses and fixes.
The Purdue networking team uses Cisco's software to monitor the network, troubleshoot problems remotely, and determine which help-desk requests require a site visit, Ksander said. Once in the field, they use inSSIDer, an open-source wireless troubleshooting tool, or the Intel built-in tool for signal measurements.
WCS functions as a sort of controller of controllers and also allows users to upload building floor plans and specs to determine the best WLAN design, according to Chris Kozup, Cisco senior manager of mobility solutions.
"It's kind of the aggregator of information. You always have a single point of visibility into the network," Kozup said. "It's getting visualization into [radio frequency], which of course was previously something that was invisible."
But Cisco isn't the only player here. Aruba Networks markets its Adaptive Radio Management (ARM) platform while the Enterasys Network Management Suite (NMS) also offers a range of monitoring and control features, according Ronald Gruia, a principal analyst at Frost & Sullivan.
To make life easier -- and lessen site visits -- network administrators should also look for wireless network management tools with the ability to autocorrect problems and load balance APs, DeBeasi said.
"The big thing is moving toward a self-regulating and automated management … [to have] the ability to have the network adapt dynamically to what's happening in the environment so the human does not have to get involved," he said.
For wired speed, wireless LAN access points should be 802.11n
Deploying a large-scale wireless LAN as a network that matches wired speed and reliability means 802.11n is a necessity, industry analysts say.
"Sometimes you have single-radio APs that are supporting only 802.11b or g. That limits the number of available channels for coverage, so it ends up limiting the available channels for capacity," Gruia said. "[High-density areas] should be the ones to receive the new infrastructure. That's crucial because those are the chokepoints."
At Purdue, Ksander learned the hard way that large lecture halls with legacy Cisco 802.11bg APs could not tolerate 600 students logging in at the same time to access bandwidth-heavy applications for the class.
"We tried it in our [802.11b/g rooms], and the density factor just didn't work," said Ksander, who will be removing the older APs over the coming weeks.
Wireless networking with 802.11n also offers more security, using Wi-Fi Protected Access (WPA) versus Wireless Equivalent Privacy (WEP) encryption, Gruia said.
"On a large campus, that's a big issue, especially if you're talking about a public library with legacy access points that are supporting a weak encryption like WEP or they don't support any encryption at all," he said. "A smart hacker could come in and start sniffing on those networks."
Let us know what you think about the story; email: Jessica Scarpati, News Writer