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802.11n — Why now, why not?

September 4, 2007 - 4 Comments

There has certainly been a good deal of industry discussion, or should I say a good dose of vendor hype, around the new emerging standard for Wi-Fi, 802.11n. Through all of the wild-eyed claims of performance increases and radical shifts in the world of enterprise networking, I thought I would offer up some humble (or maybe a bit beyond humble) perspectives on the state of enterprise Wi-Fi, the emerging 802.11n standard, and what customers really need to consider on this front:1. First and foremost — 802.11n certainly represents an intruiging step forward for the wireless industry. It promises to deliver a significant step up in performance, which has been well covered in press. What is not as well covered, but perhaps even more compelling for customers today, is the substantial improvement in overall reliability that 802.11n will bring to networks. No customer is expecting an immediate “0 to 100%” shift to 802.11n users and clients. With the backwards compatibility of .11n, for existing .11b/g users, the compelling ‘why to migrate’ now case will often lie with reliability for all Wi-Fi clients across the business.2. Make no mistake — moving to 802.11n is both a wireless AND wired decision. Given the theoretical available bandwidth in a dual-radio .11n access point of 600 mbps (300 mbps per radio — expect closer to 130 Mbps, no matter what vendor release you read) there is an obvious need to provision a 1 Gbps Ethernet port to backhaul the AP traffic. Another critical deployment consideration is how to power these new access points. Any competitive 802.11n AP requires more power than is provided via a standard 802.3af power-over-Ethernet port. Workaround options include provisioning two 802.3af ports (not high on any IT department lists of desireable activities — run more wire to the AP…) or my personal favorite, utilize one 802.3af port, and run a dual radio AP in “pico cell” mode (code for running at half-capacity and performance). External power injectors are always an option, as are the ole AC power outlets, but the latter could put a crimp in any deployment.3. Here is where having a nice Ethernet switching franchise comes in handy if you are a vendor in this space (and where claims of 802.11n representing a major vendor market share shift fall way short). Cisco is announcing today its new Enterprise WLAN 802.11n offering today, and it is about more than the access point (which is quite a nice, modular platform). It is equally about delivering a true wired and wireless solution that actually considers how a customer could actually deploy with as much simplicity, and as little network architecture disruption as possible. Cisco will be delivering an auto-negotiating, single port extended power capability across switches in its Catalyst 3750, 4500 and 6500 families. This means, with a large number of customers out there, customers will be able deploy 802.11n and utilize their existing wiring closet switches to deliver the extra power required to take advantage of those wireless performance and reliability kickers that 802.11n offers. Delivering the easiest power solution for 802.11n may not make for the best headlines, but it is one of those fundamentals that must be addressed.4. So that brings me to my last thought — I’ve been reading some recent comments by a Enteprise WLAN vendor wondering aloud to the press why any vendor would ship a 802.11n draft 2 solution today. The reasoning centered around two key points: the final standard has not been ratified, and Cisco hasn’t announced a product. Well — to comment on the Cisco point, we have announced a product, and it has everything to do with customer demand and supply chain reality. Customers are starting to ask for 802.11n. Chipset manufacturers like Intel and others are shipping 802.11n silicon. PC manufacturers are releasing 802.11n-capable product. The market seems to have spoken, and to follow the lessons learned from earlier Wi-Fi days — clients will drive the infrastructure. Cisco chose a deliberate approach to this space — get Wi-Fi Alliance (and it turns out, the only to date..) certification, participate in the test bed, and then bring 802.11n product to market. On the final standard ratification point — I’d offer that given the supply chain momentum and rising customer interest in 802.11n draft 2, it becomes hard to argue why any serious vendor wouldn’t have an offering. While there is no 100% guarantee, it is truly hard to imagine any upgrade beyond software to bring an 802.11n draft 2 product into compliance with the final standard. So to the vendor that just last week asked why .. I’d respond .. why not? So to be sure, the emergence of 802.11n for businesses will be met by a distinct, early adopter market over the next year. Such customers certainly deserve both an easy, deployable solution, and also information to set expectations on the performance, reliability and reach of this new technology. Please visit on an ongoing basis for more information on 802.11n, including soon to be released information on benchmarking testing between Cisco and Intel. Enough of pre-announcement press releases — let’s dig into the reality of 802.11n. What are your expectations for performance, reliability, and reach? Any plans to deploy soon? Next year? Three? Never? Please share!

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  1. Assuming the 802.11n draft is developed further, will there be firmware upgrades available to support any changes that are bound to come up before ‘release’ as it were…?Customers are worried that draft n kit will be obsolete come 2010.

  2. In all of the Cisco 802.11n articles I’ve read or glanced at, none talk about preferred wiring specs. Is CAT5e okay to use? If yes, should it be recertified for Gig speeds? Or, will we have to replace all of the CAT5e with CAT6 for the AP’s to eventually run 802.11n?

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  4. good article