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John Cox has an interesting rundown on large installations picking 802.11n for client use instead of upgrading or adding more Ethernet: Cox, in a Network World story, starts with the observation that some companies and many colleges are finding huge numbers of unused Ethernet ports, which means they're paying depreciation and operating expenses on gear they're not using.
One school he speaks to has 80 to 90 percent of its Ethernet switch capacity unused. The CalState system performed careful analysis of current use and opted to cut 2,500 switches, which will save $30m in hardware-related spending, exclusive of HVAC/electricity savings.
At colleges, this is a simpler matter, because campuses can simply eliminate new spending for Ethernet in dorms and elsewhere and pull switch plates and switches, or reduce the number of jacks by a large number without impairing functions. While some students might have desktop computers, surveys keep finding that most arrive at campus with laptops or purchase them on arrival. Businesses may still need to have Ethernet active because of their heavier desktop use.
For instance, in a 2008 survey of incoming students at the University of Virginia, with 95 percent of students surveyed, a single person in the 3,071 asked did not own a computer. That number was as high as 26 percent (634 of 2,437) in 1997, but has dropped to a negligible amount since 2003 (30, 10, 18, 4, and 4 in successive years had no computer).
Now out of those 3,070 computer owners in 2008, only 36 had desktops. That's a lot of spending on Ethernet for 1 percent of students. And those desktop systems might have had Wi-Fi built in if they were Macs (Mac Pros are the only model that requires an add-on build-to-order Wi-Fi adapter) and most student/entry-level oriented Wintel systems.
802.11n found its way into colleges quite early, but enterprises now have a wide range of affordable options from major and minor vendors alike that are proving more cost effective than 802.11g or a/g was because of the greater capacity and range of 802.11n. Everything I hear from companies and read in reports shows that dual-band 802.11n overcomes almost ally of the gating factors that made 802.11g useful but not strictly a wired replacement for clients.
Most clients don't need anything like the 100 to 150 Mbps throughput that 802.11n can offer in ideal cases. Rather, each client may need from 1 to 10 Mbps in a more or less reliable and guaranteed fashion, and with a multi-channel switched WLAN, enterprises can easily deliver that.
College campuses have lower requirements, seemingly, with Cox noting that 1 Mbps is a reasonable threshold for common activities. In those cases, you need networks that can support massive concurrent users in relatively small areas, like classrooms or quadrangles, a very different requirement from the business network.
No one's suggesting Ethernet will be pulled out. It's still the only way to run critical services, and you need quite a lot of it to backhaul all the WLAN systems that are being put in. But there's a growing divide between client Ethernet and server/backhaul Ethernet that can let companies and colleges trim their IT budgets without reducing utility for their users.
You have nothing to lose but your cubicles and your sense of day-to-day security: Companies are starting to look big-time into allowing flexible work environment that don't lock people into a single cubicle or office. This allows them to use office space more densely but flexibly and lets people work more to their liking. Of course, some people like a cubicle, don't they?
One of the drivers for increased mobility is that thin APs require less management--a claim long made by thin AP makers and confirmed when Cisco bought Airespace--and greater flexibility. It's clear Microsoft chose Aruba not just because they were thin, but because their approach is commodity-driven with enterprise-class management: that is, magic in the APs is less important than magic in the central console. (Microsoft may also have chosen Aruba because of its remote AP option in which APs can be added using IPsec security over any remote Internet network.)
The other drive is, of course, 802.11i and its integration into branded standards as WPA2. With WPA2 Enterprise, companies finally feel like they have the strongest possible security at their disposal.
The companies discussed in this excellent article have found big cost savings across the board, but those also come with more worker satisfaction and increase productivity.
I'll be curious on a long-term if workers without a place to hang their hat reliably every day who do spend most of their time in an office feel less tied to a company. In a classic Dilbert, after offices are deassigned, Wally moves his stuff around in a grocery cart and engages in office graffiti.
Aruba beats out Cisco (Airespace), Trapeze: The Microsoft campus and worldwide offices will be upgraded from its current Cisco infrastructure to use 5,000 Aruba access points, part of a WLAN switched network. The Wall Street Journal reports the deal covers 281 buildings in 83 countries to support 25,000 simultaneous Wi-Fi sessions. One of Aruba's bits of magic is IPsec tunneled remote APs that can use a centralized switch located over a WAN.
This is an enormous win for Aruba, which has been accumulating customers, but it seemed that the safe money was on Cisco because of the Airespace acquisition.
Meru Networks has announced its multi-radio omnidirectional Wi-Fi switch: It took me a while in a briefing last week to understand Meru's approach, but I get it now. Meru puts four, eight, or 12 radios in a single switch which is deployed in zones around an office. Instead of using centralized network intelligence to manage the RF characteristics of their APs, they put many radios in a single box and don't deal with trying to avoid co-channel interference at all. They can use combinations of 802.11a channels and three 802.11b nonoverlapping channels or go all 802.11a.
When you deploy Meru equipment, each switch runs multiple channels at once using omnidirectional antennas. Zones touch other zones and the switch decides which clients are allowed to join which channel based on load. All radios on the same channel use a virtual MAC address that prevents a client from deciding which radio to switch to. Instead, the switch decides which clients are on which channels.
The value of this is that clients don't have to hop from channel to channel at zone interstices nor does the RF intelligence have to manage power in the same way that a network of APs operating on non-overlapping channels across coverage zones do.
A denser standard network involves adding more access points in given areas on non-overlapping channels to create more effective bandwidth. A denser Meru network involves creating more cells using their switches at the center.
Meru's approach is part of a new trend which Extricom and Xirrus are part of in which the switch is out in the office instead of in the server room, and Layer 2 decisions are made at the switch itself, reducing bottlenecks. Authentication and other Layer 3 issues are tunneled back to server rooms.
Putting switches out in the office means that you have to have service-level agreements that can cope with the failure of a device that might be serving 100s of users and be the only coverage for a given area. The integrators that resell this equipment have to meet the enterprise need. For instance, Meru doesn't have redundant, hot failover power supplies on their switches, which is common for server-room devices.