Wi-Fi won't kill the office LAN ... yet
- — 29 October, 2010 05:19
While Wi-Fi has increasingly become the primary choice for office worker connectivity, it may be some time before it replaces wired networks altogether, according to panelists at the Interop conference, held last week in New York.
In many cases office wireless networks are more widely used than the wired networks in place, the panelists agreed. Which leads to the question: Do we need Ethernet-based LANs at all?
"The primary problem I see is that companies don't see their wireless networks as the primary edge, whereas users do," said Austin Hawthorne, a senior consulting systems engineer for Aruba Networks, during one panel on the future of Wi-Fi. "As a result, the wireless network [in many organizations] is underbuilt and overutilized, whereas the wired network is overbuilt and underutilized."
"You build your wireless networks to fill in coverage holes and to provide mobility, but it ends up being your primary network," agreed Joe Epstein, senior director of technology for enterprise wireless equipment at vendor Meru Networks.
This approach is both costly for the organization and frustrating for users, the panelists argued. Organizations have invested heavily to run cables, even if the employees then make more use of the office Wi-Fi, slowing its performance.
But are organizations ready to cut the cords?
"We're not quite there yet," said Scott Lindsay, a senior director of advanced technology for Hewlett-Packard. "Wired technology still does have a performance advantage, it is better understood. It is a gap that is starting to close, but it's still there."
Enterprise interest in Wireless Local Area Networks (WLANs) seems to be growing. In the first six months of this year, vendors shipped 422,300 802.11n access points, compared to 520,400 11n access points for the entire prior year.
And beyond the numbers there may be a cultural shift more difficult to quantify. Apple CEO Steve Jobs has commented, for instance, that iPads and iPhone are already being used or tested in 80 percent of Fortune 500 companies, with no push from Apple whatsoever on the enterprise market.
"Devices are changing and user expectations are changing," Epstein said. As a result, these devices are changing the workflow of organizations.
In terms of the enterprise, properly deployed WLANs can "do everything" that LANs can do, asserted Craig Mathias, a principal of the Farpoint Group analysis firm who moderated an Interop panel on the future of Wi-Fi. The security and reliability can be just as robust as on wired networks, and, in terms of bandwidth, the next generation of Wi-Fi devices should equal throughputs of Gigabit Ethernet, he argued.
The current standard for Wi-Fi, IEEE 802.11n, can offer bandwidth of up to about 100M bits per second, using either the 2.4GHz or 5GHz frequency bands. This falls short of the potential 1G bits per second offered by the Gigabit Ethernet cards now installed in most new personal computers and laptops.
That disparity will close over the next few years, the panelists argued. Engineers are working on two next-generation 802.11 standards that should produce Gigabit-level bandwidth: 802.11ac (which will use the 6GHz band) and 802.11ad (which will use a 60GHz channel).
The 802.11ac specification "is definitely something to keep watching; it will be the network" after 802.11n, said Bob Friday, a director of strategic initiatives for Cisco's wireless, security and routing technology group.
In either case, this next generation of 802.11 hardware may not show up until 2012 at least. "The chip manufacturers are investigating this, but as far as having something concrete to alpha test, they are not really talking about it. Until they can come to us and say here is our base code and chipset, it's not real," said Devin Akin, chief Wi-Fi architect for WLAN equipment provider Aerohive.
Comparing bandwidths between wired and wireless may not be a useful indicator anyway. Meru's Epstein noted that while many deployments today use Gigabit Ethernet connections, it hasn't been a driving requirement for the enterprise, which may not require that much bandwidth for each endpoint anyway. It is simply the standard that is in place.
Farpoint's Mathias noted that wireless offers advantages over wired networks. It's easier to add wireless than wired clients to networks, wireless networks don't suffer outages from faulty cables, and though electromagnetic noise can be a problem, Wi-Fi was built to work in noisy environments -- it can step down the bandwidth to work around noise issues caused by microwaves, XBox controllers and other Wi-Fi networks in its range.
Still, panelists agreed that Wi-Fi needs more management tools and practices before it can be considered a full-fledged alternative to LANs.
"It needs to be reliable to the point where you just put the network up and it works. You need to not worry about device behaviors, or load balancing or any of that. The system needs to figure out a lot of it itself," Epstein said. "With the right wireless technology, you can make wireless technology work like wired technology."
HP's Lindsay noted that while networking administrations understand much of wireless technologies, there are elements not well-known by those without wireless experience. "Engineering a wireless network is different than how a wired network is engineered," he said.
Aruba's Hawthorne noted that organizations have to think about scaling their wireless networks like they do their wired networks. For instance, most organizations set up subnets to organize their networks, yet this is not done as frequently for wireless networks. As a result, he has seen wireless networks with 4,000 clients on a single subnet.
Perhaps the best approach, for the short term, may not come in an either-or answer, but rather a hybrid approach.
Lindsay noted that while HP has the equipment that would allow an organization to set up an all-wireless infrastructure, in fact most customers go with a hybrid model, one that combines wires and wireless into a single network architecture.
"We'll architect a network any way the customer would like it architected," Lindsay said. "But what we end up finding is that [customers don't want] all wired or wireless, but both."