LAN/WLAN integration growing, but snags persist

Wired, wireless networks still not unified

Ethernet switch vendors that offer combined or unified LAN and wireless LAN gear say the ultimate goal is to get wired and wireless network technologies to appear as a single network access layer. However, switch vendors and industry experts say this is still a ways off -- both in terms of the technology, and the demand for unified gear from users.

"We're still in the early days of unified LAN/WLAN networks," says Craig Mathias, an analyst at Farpoint Group, a Massachusetts-based WLAN consultancy. "I wouldn't say any offering is really complete at this point. It's an enormous technological and marketing challenge to get everything integrated together" -- where switches, access points, management software are all unified with a single security architecture.

"It's going to take a while until we get to that point," says Mathias, who is a columnist.

Many analysts and industry observers say that corporate WLAN technology -- particularly, WLAN switch technology -- would be absorbed by LAN switch vendors in the long run. The thinking goes that business IT administrators would prefer wireless and management of the WLAN integrated into a wired infrastructure.

Vendors such as Cisco Systems Inc., 3Com Corp. and others have offered WLAN for more than 10 years. But this gear was based on the thick-access-point model, where an access point has its own IP address and is managed as a separate network element. In 2002 and 2003, WLAN switching emerged, with a new approach to wireless. Access points are managed as network-attached radios, tied to a centralized WLAN controller or switch, which provides central access settings, configuration and security. This is what is called an overlay network: The WLAN is essentially a second network, laid on top of the base Ethernet LAN. Security, physical-layer access and management are two separate realms.

Unification on the surface

Most LAN-switch vendors with WLAN offerings sell technology bought from, or acquired by, WLAN switch start-ups. They offer WLAN- and LAN-management tools that tie together policies, device management and other tasks for wired and wireless clients, even if these users are connecting via pieces of equipment that were not developed by the same company, originally.

"Cisco has made significant progress in that area, and they're probably the leader at this point," in terms of offering unified LAN/WLAN gear with a meshed network-management layer, says Mathias.

Ben Gibson, director of mobility solutions marketing at Cisco, says WLAN technology eventually will be absorbed mostly into Ethernet-switch infrastructure. But it will take time.

"The longer-range view is that this is the direction we'll go," he says. "But there is a need for organizations to deploy WLAN controllers, either in an integrated or stand-alone fashion, depending on what they need to do."

Cisco offers WLAN controllers that can be integrated into its switches, such as stackables and Catalyst 6500 chassis. It also has WLAN controllers that run as stand-alone appliances, for the true WLAN-overlay model; Cisco acquired this technology when it purchased Airespace in 2004.

What Cisco has focused more on in the meantime is bridging the network-management tools used to control security and configurations of Ethernet and 802.11-based gear. This is what users want the most.

"Not too many IT organizations that can afford to double the size of their network-management staffs," he says.

Other purveyors of WLAN/LAN gear say the level of integration between the two depends on the size of the company and what problems users of the gear want to solve.

"When people talk about unified networks, they talk about multiple things, and that adds to the confusion," says Suresh Gopalakrishnan, vice president of the emerging products group at Santa Clara, Calif.-based Extreme Networks. On one level, there is the overall appearance of a unified network. This involved setting policies for security or access that are the same for wired and wireless policies. It also involved management. Extreme Networks, for example, offers a network-management tool that allows users to configure access settings and physical device settings for Ethernet ports and WLAN access points.

Another level of unification is having WLAN access-point controller and management features built into LAN switches. This is more popular in smaller networks, with fewer LAN switches at the edge. Or in networks that are widely standardized on one vendor's specific product.

"If the LAN edge is homogenous," Gopalakrishnan says, "then having wireless technology in the edge switch is great. You have complete control of both types of networks."

Overlay, here to stay

Most networks are not so homogeneous -- even if a single LAN vendor is in place, a mix of older and newer switch models at the edge is closer to realty. This is what keeps many companies from adopting tightly integrated gear, others say.

"We don't feel or believe that unified WLAN and LAN technology has matured to the point where it can be tightly integrated successfully, without causing some degree of forklift upgrades down he road," says Bob Schiff, vice president and general manager of the enterprise business unit at Foundry Networks Inc., which is also based in Santa Clara.

"What we're seeing from customers -- and expect to continue to see for at least the foreseeable future -- is that customers will often choose an overlay model for the wireless," Schiff adds.

Like Extreme, Foundry has software and upgrade technology that can turn its LAN switches into WLAN access-point controllers. But customers are choosing Foundry's WLAN controller-based products -- and the overlay architecture -- the company offers.

The fundamental differences in WLAN and Ethernet LANs -- radio waves vs. electric currents over copper -- and the differences in deployment and management that stem from these differences, are the reason. Unrelated to the daily chores of maintaining a wired Ethernet LAN are site surveys, rogue access points, radio frequency and interference issues. This is why a relative degree of separation is good, Schiff says.

Scott Hilton, vice president of product management at 3Com, shares Schiff's view that no one wants to swap out a whole LAN edge layer to do wireless. "There isn't a good business reason for it," he says. "The overlay model will be around for a long time as a result."

3Com says tightly integrated LAN/WLAN gear is more popular among its small and midsize customers. For these users, it offers the SMB Unified Wireless Switch -- a LAN switch with built-in WLAN access-point controller technology. But this box is aimed at organizations with fewer than 500 employees, not large companies.

Later this year, 3Com plans to expand integrated LAN/WLAN technology with its Open Network Services (ONS) module -- a Linux -based blade that runs in its stackable and modular switches. Hilton says 3Com is working with WLAN partners to put a WLAN controller into the ONS blade, which will run on 3Com's 5500 series of high-end stackable switches.

Standards may drive adoption

One factor that could drive more integration of WLAN technology into switching in the near future is the completion of the 802.11n standard. This IEEE standard, ratified this month, supports speeds of up to 540Mbit/sec. and operates on both the 2.4 GHz and 5 GHz channel spectrums.

"Until recently, enterprises were noodling with WLANs, but not really deploying widely," says Mathias. He calls 802.11n "the linchpin" that could enable widespread WLAN adoption, as well as deeper integration of 802.11 technology into the Ethernet infrastructure.

When 802.11n is set and shipping, says Mathias, "there will be less worry on the part of enterprises about having to roll over their wired network to support some new [802.11] standard coming down the road."

This story, "LAN/WLAN integration growing, but snags persist" was originally published by Network World.

Copyright © 2007 IDG Communications, Inc.

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