Till now, wired and wireless switches have always adapted to new bandwidth with faster core capability, says Hockaday. "Why would a vendor want to switch at the edge?" he asked. "Cisco and Aruba have the ability to invest in high performance switching at the core, while other wireless switches may be built on PC platforms and the vendors can't afford to get the high performance silicon required for faster core switches."
In fact, Aruba already offers the option of splitting traffic and switching some nearer the edge for situations where it is useful, such as branch offices, he said. "We think centrally switching is the best way, but we give people all the options that are necessary."
Trapeze Networks responded by arguing that upgrades to the central switch are costly and not necessary, if distributed switching can manage the load. "Trapeze customers who upgrade to 11n use the controller they already have installed," said Michael Coci, director of technical marketing at Trapeze. "Aruba customers who upgrade to 11n must buy new APs, plus the controller hardware necessary to support them. That means higher costs, additional hardware, and added customer effort."
"If customers like the centralized forwarding path, Trapeze will certainly sell them hardware that is capable of 802.11n speeds," said Matthew Gast, director of consulting engineering at Trapeze. "The raw data throughput of switch fabrics isn't a barrier for us in the wireless industry. We can all buy switch fabrics that move data through the network at wire speed. The barrier is in performing all the crypto operations for client devices."
Coci likened Aruba and Trapeze's 802.11n upgrades to recent operating system upgrades from Microsoft and Apple: "If I'm a Microsoft customer who wants to upgrade to Vista, because of the heavier requirements I have to buy new hardware. If I'm an Apple customer and I want Leopard, I buy the new OS, and enjoy all the new functionality while running it on my existing hardware. Which vendor's customers are better served -- which vendor has the better architecture?"