Posted by: Paul DeBeasi
Many enterprises are considering Wi-Fi CERTIFIED™ 802.11n draft 2.0 deployment because it has significant advantages over existing wireless technologies. However, these advantages present the enterprise network manager with important deployment considerations. At the upcoming Burton Group Catalyst Conference in July, I will examine the various deployment considerations for 802.11n in the enterprise. Some of the topics I will discuss are listed below.
Most existing 802.11 devices operate in a single frequency band, (e.g., 2.4 GHz or 5 GHz). 802.11n is different because it is specifically designed to operate in both the 5 GHz and the 2.4 GHz frequency bands. So 802.11n presents an opportunity for enterprises to reconsider which frequency band(s) to use. I will discuss some of the tradeoffs and issues enterprise managers need to consider.
Legacy 802.11 access points (APs) have a maximum power draw that is very close to the IEEE 802.3af Power over Ethernet (PoE) maximum of 15.4 watts. However, many 802.11n APs will consume more power than legacy APs. Enterprise AP vendors have addressed this problem in several ways and enterprise IT managers must consider which approach they will select.
802.11b/g/a APs typically use Fast Ethernet ports to forward traffic onto the wired network. Because the 802.11n data rate is designed to exceed the 100 Mbps capacity of Fast Ethernet (especially when using 40 MHz channels), most new APs will use Gigabit Ethernet for wired Ethernet communication. Therefore, some enterprises may choose to upgrade a portion of their wiring closet switches, and possibly their cabling, to provide gigabit Ethernet links to their 802.11n APs.
WLAN controllers that perform the data-forwarding function must backhaul all wireless traffic from hundreds of 802.11n APs, and so each controller will likely need to support several Gigabit Ethernet connections. WLAN controllers that distribute the data-forwarding function to the AP will need only a single Gigabit Ethernet connection.
802.11n presents a new security challenge because existing hardware sensors, without software updates, may not be able to recognize 802.11n APs. Therefore, it is important for enterprise managers to update wireless intrusion detection systems (IDSs), regardless of whether or not they plan to deploy 802.11n.
802.11n will impact network management tools. For example, spectrum analyzers must be able to recognize MIMO spatial streams, and visually communicate network behavior to the user. Therefore, enterprise managers will need to upgrade their network management tools in order to manage 802.11n networks.
Please join me in beautiful San Diego, July 27 – 31, for a discussion of these issues and many other interesting topics. Learn more about the Burton Group Catalyst Conference here: http://www.catalyst.burtongroup.com/Na09/.
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