Interoperability Issues Infest Wireless LANs

By Jacqueline Emigh | Mar 31, 2003 | Print this Page
http://www.enterprisenetworkingplanet.com/netsysm/article.php/2172691/Interoperability-Issues-Infest-Wireless-LANs.htm

With equipment prices falling and the number of hot spots rising, wireless LANs will become more predominant in 2003 than ever before. For network managers, though, vendor interoperability is expected to remain an issue across areas ranging from encryption to configuration management tools.

According to recently released research from Gartner Dataquest, worldwide end user spending on WLAN equipment grew 38 percent in 2002, but unit shipments almost doubled, including 15 million adapters and 4.4 million access points and gateways. Pricing fell 37 percent on average last year, and Gartner predicts a further price drop of 25 percent in 2003.

Analysts point to Intel's Centrino technology and hotspot initiatives as two additional factors that will fuel future market growth. "Intel is investing in the (Centrino) processor, chipset, and radio, as well as in branding and marketing test validation. There will be very much of a push to make wireless go," claims Mark Margevicius, a research director at GartnerGroup.

No Common Management Framework Yet

Progress has been made around security protocols, but WLAN technology still lacks a common management framework. "There is no common management infrastructure, and I think interoperability will continue to be an issue. Management is one of the ways in which vendors like to differentiate themselves. There is a difference between a $99 access point and one that costs several hundred dollars more, with better service and support," according to Margevicius.

Today's wireless access points (APs) are typically bundled with their own built-in administration tools. Vendors have already been responding, though, to growing demand for WLAN with new products for network management and security. Cisco and Symbol, for instance, already have products on the market for remote policy-based administration.

"Products like Cisco's Wireless LAN Engine and Symbol's Mobius save administrators from having to go to each access point to enter in MAC address filtering information, for instance," states Brian Moran, marketing manager at AirDefense, a hardware appliance for rogue detection, intrusion detection, and encryption monitoring.

Cisco has been supporting its Aironet WLAN management technology in edge switching products as well as in access points and wireless cards. Last fall, Symbol expanded its own Mobius technology to edge switching, too. In February, Proxim chimed in with Maestro, an upcoming switch-enabled lineup that will build on its previous Harmony architecture via access point aggregation and load balancing.

Meanwhile, vendors readily admit that their switching-enabled wireless LAN management architectures don't fully play together. "That's our competitors' problem, though, not ours," quips Larry Birenbaum, general manager of Cisco's Ethernet Access Group.

Page 2: Cisco Initiative and Proxim's Maestro

Cisco Initiative and Proxim's Maestro

A few weeks before Intel's Centrino announcement in March, Cisco unveiled a program offering free licensing of Cisco's Aironet wireless technology to makers of wireless cards and other mobile equipment. Intel has already opted in to Cisco's extensions program, along with IBM, HP, Texas Instruments, Agere Systems, Atheros, Atmel, and Intersil.

Compliant vendors will be able to use new Cisco Compatible branding, signifying compliance with Wi-Fi, 802.11, and the Cisco Wireless Security Suite, as well as compatibility with Cisco's "scheme for assigning wireless LAN clients to VLANs," officials report.

Intel is also permitting PC makers to use Centrino processors in conjunction with wireless chips and RF radios from other vendors. Yet PCs in this category won't be able to wear the Centrino branding, unlike those that are based on the entire Centrino package.

Beyond issues with VLAN schemes and cross-vendor management, wireless equipment can differ along a variety of other lines, running the gamut from encryption protocols to the types of RF radios used, according to Scott Ruck, business development manager at Proxim.

Under Proxim's forthcoming Maestro architecture, some non-Proxim access points will be manageable only at the SNMP level, Ruck acknowledges.

AirDefense's Moran suggests the use of the AirDefense appliance or packet sniffing software in conjunction with multiple other levels of security, including wireless vendors' management tools, firewalls, Radius servers, and VPNs. Outside of its other functions, AirDefense is geared to centralized, air-based rogue detection over a wider range than software packet sniffers.

Some of AirDefense's customers, though, have already run into interoperability problems with wireless vendors' management tools, according to Moran. "The obvious answer is to get all your access points from a single vendor. However, lots of organizations find that branch offices have already gone out and bought their own wireless equipments." Mergers and acquisitions can also result in a hodgepodge of multivendor equipment.

As another management solution, Moran points to third-party WLAN gateways. Bluesocket, for instance, provides policy-based installation, maintenance, and management across wireless architectures from multiple vendors.

Enterprise management vendors are also getting into the act. Computer Associates, for example, is now developing a module for CA-Unicenter aimed at supporting multiple vendors' WLAN architectures, sources at CA have revealed. Now in closed beta with general availability slated for spring, the product is known as Unicenter NSM Wireless Network Management Option.

Page 3: 802.11i to Resolve Security Issues?

802.11i to Resolve Security Issues?

The Wi-Fi Alliance's Wi-Fi Protected Access (WPA) is often seen as a transitional step to 802.11i, the IEEE's emerging wireless encryption standard. Wi-Fi, though, has no initiative under way for management tool interoperability, according to Brian Grimm, spokesperson for that organization. Instead, wireless vendors have been working on these interoperability issues through another IEEE effort known as 802.11f.

"802.11f, though, is not a proposed specification. Instead, it's only being proposed as a 'recommended practice,' meaning that vendor compliance is completely voluntary," Grimm continues. Still an unapproved draft, 802.11f targets roaming and AP registration issues.

The IEEE's emerging 802.11i draft, on the other hand, will be an actual specification. By and large, vendors are promising to support 802.11i as soon as the IEEE spec gets finalized.

However, industry reports are starting to surface that 802.11i does not offer backward compatibility with existing 802.11b wireless cards. Although 802.11b cards will soon be supplanted by dual-band 802.11a/802.11b cards anyway, there are certainly a large number of 11b cards already installed and running.

What's a Network Manager to Do?

What's a network manager to do? One common approach to interoperability problems is to wait for industry standardization. When it comes to WLAN management, though, that clearly won't work for a lot of organizations. Standardization around all of these issues will take too long -- either through industry groups or on a de facto basis -- if it ever happens at all.

One possible solution is to decide to stick with a single wireless vendor now and into the foreseeable future. Alternatively, you can keep your eyes open for management products that support multiple wireless LAN architectures -- possibly in conjunction with wired networks, too.


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