How will 802.11n wireless LANs affect the corporate net?
Summary
A surprising number of wireless LAN vendors have recently announced enterprise access points based on the draft IEEE 802.11n standard, promising throughput of 100 Mbit/s to 200 Mbit/s per frequency band, or from three to six times that of todays 11g and 11a nets. Whether network managers opt for the draft 11n products, certified interoperable by the Wi-Fi Alliance, or wait for the final IEEE ratification in late 2008 or early 2009, they could face any of these four issues: overloading part of the wired infrastructure; overloading existing, older wireless LAN switches; forcing an upgrade to higher-powered Power-over-Ethernet; and repositioning and rewiring some number of existing wireless access points. Vendors have been upgrading their controllers over the past year with 11n in mind, sometimes also offloading the packet switching functions to the access points, creating a distributed data plane. "The PoE infrastructure may have its upper limits tested by 11n deployments [that are] used to their maximum capabilities," says Chris Silva, analyst at Forrester Research. At least one vendor, Trapeze, has created new code that can let its just-announced 11n access point make use of existing PoE injectors, but there are tradeoffs in terms of performance.