Tools Ease WLAN Management

Wireless LANs give users a tremendous amount of freedom, but they also give network administrators a daunting task of management. Part of the difficulty of managing WLANs is due to their open nature -- wireless data does, after all, travel through the air.

Complicating matters is the fact that devices with intelligence equivalent to that of sophisticated switches are being pushed beyond the edge closet and farther from admins' chairs. Also, access points (APs) installed in enterprise ceilings and on walls, with their slew of configuration parameters and the ever-changing nature of radio frequency (RF), can make managing WLANs difficult and time consuming.

If you use a single access point vendor, solutions like Cisco's Wireless LAN Solutions Engine (WLSE) are enough. By adopting a vendor-agnostic (or nearly so) management platform, you'll give yourself room to maneuver when it comes time to upgrade and add on to your network.

That's where AirWave's and Wavelink's management platforms come in. They each support a multitude of AP vendors and models and aim to take the hassle out of administering vendor-diverse WLANs. They also promise to scale to meet the changing management requirements of your infrastructure as it grows.

In our Syracuse University Real World Labs, I set up a test bed subnet on which I installed both AirWave's AirWave Management Platform (AMP) 3.0 and Wavelink's Mobile Manager 5.7. To test their management capabilities, compatibility and their access point discovery abilities, I also placed a slew of diverse APs on the same subnet, both current and legacy devices. In addition, I put one AP a router-hop away on another subnet to test each platform's abilities to discover and manage APs on remote networks.We found both platforms to be similar -- in most ways. Once they support a given AP and firmware version, both systems enable you to manage all your APs, via SNMP, HTTP, and telnet using a single graphical interface. However, while the platforms have similar features sets and functionality, AirWave's AMP came away the clear victor for its ease of use and the flexibility it offers administrators thanks to its Web-based design.

AirWave Management Platform 3.0

Installation of the AirWave Management Platform was straightforward and easy. The hardened Linux-based server arrived in our lab preinstalled on a 1U Dell machine and only required IP address configuration through a command line interface. After that, I could access its Web-based configuration pages from any PC on my test network.

Unlike Wavelink's Windows application-based Mobile Manager, AirWave's AMP simplifies administration efforts by allowing multiple users to access the management interface at once. It also allows remote administration from any AP-reachable network. This, coupled with the easy, intuitive interface, made managing the test APs a breeze.

After initial setup of AMP, I had to configure it with appropriate SNMP, HTTP, and telnet credentials to manage my test bed of APs. AMP shares this time-intensive task with Mobile Manager, but AirWave's interface makes entering and keeping track of each entered credential easier. This entry process can be greatly lessened on both platforms in single-vendor environments and where consistent credentials are used.Discovery of all the access points on the test network, as well as the network a router-hop away was slightly easier and faster than Wavelink Mobile Manager. Presumably AP discovery need only be performed when new access points are installed and both solutions allow discovery to be scheduled so the task can run after hours.

After discovering the APs in my test bed, it took very little time to set up each AP to be managed by AMP. It was even able to quickly create a logical grouping into which I placed the access points. That eased management for general configuration settings such as extended service set identifier (ESSID) and security settings.

Grouping APs also makes it easier to apply settings profiles, which are preset configurations that can be applied to APs to ensure they are all properly configured. AMP can then routinely push this profile out to APs to compensate for any configuration deviations. Mobile Manager can perform these same functions, but its lack of an intuitive interface, coupled with its convoluted right-click-driven design, makes it a task to configure the server to handle these tasks.

Installation of Wavelink's Mobile Manager 5.7 was simple. The Windows-based application took little more than a double click and entry of a license key to get the server up and running on the test network. Once started, a setup wizard prompted me to input the management credentials of the APs and then it immediately scanned for them.

Slowly but surely, Mobile Manager found and managed all the APs in my test bed. Interestingly, the Intel 2011 AP on my test network, for which support is not offered under Mobile Manager, was recognized as a Cisco switch and I was able to change the device's IP address.After discovery and putting the APs into a logical group to ease management, I created a settings profile to ensure that all the APs were set with the same basic wireless network parameters. The test APs were then all properly configured and managed by Mobile Manager.

Mobile Manager, as with the AirWave Management Platform, does a fine job of wireless network health monitoring. I was able to both drill down to the individual AP level and gather statistics for the entire wireless LAN. Both management servers can show easy-to-read graphs depicting figures such as network utilization, capacity, number of clients, as well as a group of other statistics such as WEP and CRC error rates.

Though Mobile Manager provides more health information than most admin could ever digest, it can only gather such information while the server software is up and running. AMP is constantly running and therefore such statistical information is always being gathered.

Mobile Manager does trump AMP in one category: reporting. With a seemingly endless list of reporting topics, from network capacity information to details on packet errors and retries, Mobile Manager can quickly gather all required information and present it in HTML, PDF, and CSV formats. AMP will report on almost as many topics, but can only output statistics via email.

Mutual LimitationsWhile both WLAN management platforms have roughly the same feature set, they also share some shortcomings. Most noticeably absent in both offerings is reliable rogue AP detection and location.

Both can detect rogues by scanning APs that support the feature " both the Symbol 4131 and Proxim AP-2000 in my test bed could detect rogues. However, depending on which APs comprise your WLAN, you may be stuck without the ability to detect rogues at all or, in the case of the Symbol AP, rogue AP detection may require disrupting regular operation of the wireless segment in order to scan.

Once both management platforms detect rogue access points, they alert admin to their presence, but can only indicate which APs "heard" them and at what signal strengths The task of further location of these interloping devices will likely fall to a handheld analyzer and an administrator walking the halls.

Another shortcoming is that both management platforms support only a limited list of specific APs and firmware versions. This means that admins' future AP purchase orders are bound by their management platform's list of supported APs and that upgrading existing APs to latest firmware versions will likely render them unmanaged until support is available via a management server upgrade.

While these support limitations exist for both servers, Airwave's list of supported APs is noticeably longer, both in the vendors and specific models of APs they support.Wavelink's recent agreement with Proxim to handle their AP management needs will likely translate more as a marketing tool than as a guarantee they'll support Proxim APs sooner or better than AirWave will. In fact, not only did Airwave support Proxim's more recent offerings as well as Wavelink (neither offer support for the AP-4000 yet), but AirWave supports their legacy AP-500 and AP-1000 models, too.

Overall, though, both AirWave and Wavelink's multi-vendor AP management platforms can greatly simplify the overwhelming task of managing your WLAN. Though they lack the advanced functionality of the new wireless switching offerings such as automatic channel assignment and power output settings, and have limited support for access point types and firmware versions, these generic WLAN management systems can make central control and troubleshooting of your wireless network a manageable task.